Metallurgical Abstracts : general and non-ferrous, Vol. 2, Part 7

METALLURGICAL A B S T R A C T S

(G E N E R A L A N D N O N -F E R R O U S )

V olum e 2 JULY 1935 P a rt 7

I.— PROPERTIES OF METALS

(Continued from pp. 273-279.)

♦Young’s Modulus of Aluminium Rod Composed of Large Crystal Grains.

M iyabi Sugihara {Mem. Coll. Sci. Kyoto Im p . Univ., 1934, [A], 17, 392-396).—

[In English.] M etals composed of large grains are generally very soft. S.

measured the Young’s m odulus of alum inium rods, composed of crystal grains of various sizes, by elongation tests and by the acoustical vibration method. The value of Young’s modulus rem ained nearly th e same irrespective of the sizes of th e crystal grains, b u t th e lim it of elasticity decreased considerably w ith the grow th of th e crystal grains.—S. G.

High-Grade Aluminium. (Metallurgist (Suppt. to Engineer), 1935,10, 26-28).—A critical review of a paper by Je a n Calvet, Compt. rend., 1935, 200, 66-68; see Met. Abs., this volume, p. 137.—R . G.

♦Thermal Expansion of Monocrystalline and Polycrystalline Antimony.

P eter H idnert (./. Res. N at. B ur. Stand., 1935, 14, 523-544; Research Paper No. 784).—Measurements of therm al expansion were carried o u t on 11 sam ples of single crystals of antim ony and 3 samples of polycrystalline antim ony a t various tem peratures betw een 20° an d 560° C., an d th e d a ta were correlated w ith the results obtained by previous investigators to 300° C. The linear expansion depends on the direction along which th e m easurem ents are made.

For example, th e linear expansion along th e trigonal axis (0° orientation) of a single crystal is ab o u t twice as large as th e expansion along a direction perpendicular to this axis (90° orientation). E quations were derived which show the relationships betw een th e coeffs. of expansion an d th e orientations of single crystals. The linear therm al expansion curves of polycrystalline antim ony show th a t there is no polymorphic transition betw een 20° and 560° C. The differences in the linear expansion of different samples of poly­

crystalline antim ony are a ttrib u te d to variations in th e average orientation of th e crystals. A n illustration compares th e linear therm al expansion of monocrystalline an d polycrystalline antim ony.—S. G.

♦Metallic Gadolinium. F . T roube {Bull. Soc. chim. France, 1935, [v], 2, 740-742).—Pure gadolinium can be prepared by electrolysis a t 625°-675° C.

of a fused m ixture of gadolinium chloride 44, potassium chloride 44, and lithium chloride 12%, using 7-8 amp. a t 10 v. w ith a m olten cadm ium c a th o d e ; the resulting cadm ium -gadolinium alloy is distilled in vacuo a t 450° C. u n til all the cadm ium is rem oved, an d th e residual gadolinium is th en tre a te d a t 1230°-1250° C. in a high vacuum to produce a sintered mass w hich does n o t oxidize on exposure to a ir an d is n o t atta c k e d by boiling w ater.—A. R . P .

♦Making and Testing Single Crystals of Lead. B. B. B e tty {Amer. Soc.

Test. M at. Preprint, 1935, Ju n e, 1-8).—The creep characteristics were d e te r­

m ined for specimens composed of only one cry stal to elim inate the effect of m ovem ent a t th e grain boundaries, which, together w ith th e deform ation of the grains them selves, appear to determ ine th e creep in polycrystalline lead.

The m ethod of casting th e crystals, including th e tem perature an d tem p era­

ture gradient control necessary, is described. A n inexpensive, ra p id and sufficiently accurate m ethod for determ ining th e crystallographic orien tatio n of the crystals is presented, w hich obviates th e labour an d tim e of th e X -ray

♦ Denotes a paper describing the results of original research, f Denotes a first-class critical review.

A A

334 M etallurgical Abstracts

m ethod. R esults of creep tests of 3 specimens are given. Planes of slip are identified w ith definite crystallographie planes know n as octahedral planes.

— is. lx .

♦Estimation of the Thickness of the Contamination on the Surface¡of Metallic Lead. Shin’ichi Shim adzu {Mem. Coll. Sci. Kyoto Im p . U niv., 1934, |AJ, 17»

79-84).— [In English.] Pow der photographs of surfaces of lead contam inated by oxidation showed th a t th e contam ination was composed, m ostly of the m icrocrystals of tetrag o n al lead oxide. By com paring th e in ten sity of the diffraction lines due to th e contam ination an d th a t of th e lines of th e lead underlying, the thickness of th e contam ination was estim ated to be betw een 50 an d 200 pp..— S. G.

The Lead Cable Borer [Insect] in Japan. T akejiro N a k a ta (J. In st.

Teleg. Teleph. Eng. Japan, 1932, (109), 578-589).— [In Japanese.]—S. G.

♦Total Radiation from Soot-Covered Nickel and from Sand-Blasted Molyb­

denum. Tsuneo H arad a (Tokyo Elect. Rev., 1932, 7, 11-14; Ja p . J . Eng.

A bs., 1935, 12, 46).— [In English.] The effects of sand-blasting an d soot- covering in increasing th e to ta l ra d ia tio n from nickel an d m olybdenum surfaces were investigated b y m easuring th e to ta l ra d ia tio n from these surfaces. The to ta l em issivity of soot-covered nickel is betw een 0-46 and 0-85, according to th e thickness of th e coating; th a t of sand-blasted m olyb­

denum is betw een 1-99 an d 2-36 tim es th e value for polished surfaces. The range of tem p eratu re investigated w as betw een 800° an d 1100° K . for soot- covered nickel an d betw een 1000° a n d 1800° K . for sand-blasted m olyb­

denum . The effect of sand-blasting is greater a t lower th a n a t higher

tem p eratu res.—S. G. .

The Hardness of Single Crystals of Tin. --- (Metallurgist (Suppt. to Engineer), 1934, 9, 178-179).—A critical sum m ary of a p ap er by E . Schmid, M etallwirtschaft, 1934, 13, 301; see M et. Abs., 1934, 1, 552. R . G.

*Effect of Bismuth as an Impurity on the Structure and Allotropic Trans­

formation of Tin. C. W . Mason an d W . D. Forgeng (Metals and Alloys, 1935, 6, 87-90).—Cast “ Chem pur ” tin , w hen etched w ith a 5% solution of nitric acid in absolute alcohol, shows a peculiar netw ork stru ctu re w hich disappears on annealing a t 200° C. for 50 hrs. an d reappears after quenching or rapid cooling of th e m olten m etal. T in absolutely free from bism uth fails to show th is phenom enon, whereas i t reappears on ad d itio n of ab o u t 0-003% of bis­

m uth. The stru ctu re is a ttrib u te d to coring, since th e solid solubility of b ism uth in tin is a b o u t 1% a t room tem perature. T in showing th e cored stru ctu re undergoes th e usual w h ite >- grey m odification on cooling, whereas w hen th is stru ctu re is rem oved b y annealing an d the bism uth is all in solid solution, th e transform ation to grey tin does n o t occur. B ism uth-free tin m ay be m ade b y electrolyzing a solution containing 250 grm . of stannous chloride crystals an d 10 c.c. of nitric acid per l i t r e ; th e colloidal m etastannic acid form ed absorbs th e bism uth im purity.—A. R . P .

♦The Effect of the Oxygen Content on the Electrical Characteristics of Valvular Films of Tungsten, Tantalum, and Niobium. O. Mohr (Z. PhysiJc, 1935, 93, 298-314).—The electrolytic valve action of tungsten, ta n talu m , an d niobium is investigated.—J . S. G. T.

On the Emission Characteristics of Tungsten Filaments. T ak u ji K uno (M atsuda K enkyu Jiho, 1933, 8, (1), 4 1-54; Jap. J . Eng. A bs., 1935,13, 52).—

[In Japanese.] The ripples of tem p eratu re an d th e em ission due to th e a.c.

heating of filam ents are described, as well as th e phase difference betw een the filam ent voltage an d th e tem p eratu re ripple. K . also describes a m eth o d for obtaining th e emission characteristics a t wide ranges of th e p late voltage and th a t of th e p late c u rren t b y th e cathode-ray oscillograph. The S chottky effect is considered in particular, an d th e relatio n betw een th e area of th e active surface and th e shape factor determ ined.—S. G.

1935

/ . — Properties o f Metals 335

fThe “ Single-Crystal ” State of Metals. (Sir) H . C. H. C arpenter (Trans.

Inst. M in . M et., 1933-1934, 43, xli-lxii).—See Met. Abs., 1934, 1, 555.

—I. M.

*The Effect of Fluid-Pressure on the Permanent Deformation of Metals by Shear [Copper, Steel]. G ilbert Cook (Inst. Civil Eng. Selected Eng. Papers, 1934, (170), 1-17).—According to the m axim um shear-stress and m axim um shear-strain-energy hypotheses, applied fluid-pressure should be w ithout effect on the resistance of m etals to plastic flow ; on the other hand, M ohr’s theory relating shear-stress and norm al pressure, an d H aigh’s to ta l-stra in - energy theory oppose th is view. M easurements were m ade of th e perm anent set of m ild steel and copper w hen subjected to pure shear in a m edium of glycerine under 1 and 2500 atm . K now n values of torque were applied to the specimens, which were in the form of helices, by means of axial loading.

The steel helices were annealed a t 900° C. and th e copper a t 500° C. for 20 minutes in vacuo. W ith m ild steel, the. perm anent set below th e yield-point was on the average increased 2-5 tim es by a fluid pressure of 2500 atm . This result indicates a lowering of th e proportional lim it by pressure, b u t is in only qualitative agreem ent w ith the total-strain-energy theory. The yield-point was n o t affected by pressure. W ith copper, the resistance to plastic flow was very slightly increased by pressure, and it appears reasonable to conclude th a t plastic flow is determ ined to a very close degree by th e principal shear- stress.—J . C. C.

*A Theory of the Plasticity of Crystals. G. I. T aylor (Z. K rist., 1934, 89, 375-385).—Cf. Met. Abs., 1934, 1, 379. [In E nglish.] The experim ental facts indicate th a t plastic d isto rtio n usually consists of th e sliding of one plane of atom s over its im m ediate neighbour so th a t a perfect cry stal is reformed after each jum p. T. assumes th a t slipping occurs over lim ited lengths, L , of the slip-plane giving rise to “ dislocations ” a t th e ends of those len g th s; this avoids th e need for assum ing large forces to account for th e dis­

placem ent of th e whole slip-plane a t once. I t is assum ed th a t a t a sufficiently high tem perature these dislocations can m igrate through th e crystal under the sm allest shear-stress, an d in th is w ay a picture of th e mechanics of plastic distortion is obtained. The theory gives a parabolic relation betw een stress and strain, an d th is is confirmed experim entally for m etals which crystallize in the cubic system . The m igration of th e dislocation is assum ed to be stopped by an internal fa u lt surface, an d in th is w ay th e theory is connected w ith those involving mosaic or lineage stru c tu re s; the dim ensions of th e blocks indicated by this theory are of the order 10 4 cm. in agreem ent w ith th e evidence from o th er sources.—W. H .-R .

On the Effects of Thermal Stress and Strain on the Process or Mechanism of the Failure of Materials. M otoiti K odam a (J. Soc. Mech. Eng. Tokyo, 1933, 36, (192), 261-264).— [In Japanese.]—S. G.

On the Process and the Mechanism of Failure of Metals. M otoiti K odam a (J. Soc. Mech. Eng. Tokyo, 1933, 36, (193), 315-320).— [In Japanese.]—S. G.

On the Study of the Fatigue of Metals. Y u k iti A sakaw a (J. Soc. Mech.

Eng. Tokyo, 1933, 36, (193), 321-322).— [In Japanese.]—S. G.

*The Process of Creep of Metals. A tum aro Sim idu (J . Soc. Mech. Eng.

Tokyo, 1933, 36, (189), 7 -11; J a p . J . Eng. Abs., 1935, 13, 5).— [In Japanese.]

By combining a m echanical lever or m echano-optical device w ith a ro ta tin g drum , more m inute tim e-elongation curves for steel a n d alum inium were obtained w ith a m agnification of deform ation of 100 or 180 tim es. Sum ­ marizing th e results, S. holds th a t creep is n o t a mere plastic flow of m etal, as generally expressed, nor is i t a mere rep etitio n of sudden yielding, depending only on th e te m p e ra tu re ; it is a n altern ate rep etitio n of two kinds of deform a­

tion.—S. G.

* Abnormal Creep of Metals and Alloys During Transformation. Keiji Y am aguchi (Bull. I.P .C .R ., Tokyo, 1933, 12, (7), 594-608; J a p

1935 13 14). r in Japanese.] The ra te of creep of m etals an d alloys d u n 0 cooling an d heating increases ab ru p tly w hen th e ir m icro stru ctu re changes.

The phenom enon was recognized for tin -b ro n ze , brass, an d alum inium zinc alloy in th e case of eutectoid transform ation as well as in th e secondary separa­

tio n or dissolution of proeutectoid constituents. The sam e w as ak o ex­

perienced in th e g rap h itizatio n of cast iron in th e A 1 tran sfo rm atio n of eutectoid steel an d in th e A 3 transform ation of iron. Sim ilar phenom ena can be seen to a lesser degree in th e transform ation of (3-brass near 470 C., whereas alm ost nothing could be seen in th e A 2 change of iron. -S. G.

♦Relation Between Ordinary Strength and Creep Strength. A tum aro Sim idu (J. Soc. Mech. Eng. Tokyo, 1933, 36, (200), 831-834; J a p J . Eng. Abs., 1935, 13 i i ) . [In Japanese.] P a r t of a general research on th e creep of m etals.

S. 'w ho o-ives a theoretical explanation of creep stren g th a t high tem peratures, describes th e existence an d m eaning of creep lim it, an d th e relatio n as d eter­

m ined by experim ent betw een ordinary stren g th an d creep stren g th .—b. D.

♦Measurement of Solid Viscosities of Metals [Aluminium, Duralumin, Copper, Brass] by Means of the Flexural Vibrations of a Bar. K a tu ta d a Sezawa and K ei K ubo (Rep. Aeronaut. Res. In st., Tokyo Im p . U niv., 1933, 7, (89), 190- 231; Jap. J . Eng. Abs., 1935, 13, 15).— [In Japanese.] D escribes th e experi­

m ental determ ination of th e coefi. of solid viscosity for alum im um , D uralum in, copper, and brass, by m eans of th e flexural v ib ratio n of a b ar, th e resistance of a solid body due to dam ping being assum ed to be proportional to th e viscosity of the deform ation of th a t body. I t w as found th a t th e greater th e am plitude, the greater becomes th e coefl. of solid viscosity. S. G.

♦The Scattering of Light by Thin Metallic Films. S. R am a Sw am y (Proc.

Indian Acad. Sci., 1934, 1, 347-353).—The lig h t scattered b y sufficiently th in films of silver, alum inium , an d tin is found to exhibit th e anomalous depolarization characterizing m etallic surfaces. T his phenom enon is th u s essentially a surface effect an d n o t th e o rd in ary R ayleigh ty p e of colloidal scattering. Film s th in enough to show th e effect are found to ex h ib it no m etallic reflection and to have a very large electrical resistance. I t is sug­

gested th a t m etallic films have 3 possible different states, viz. a crystalline sta te w ith m etallic properties, a tw o-dim ensional gaseous sta te w hich is not m etallic an d is non-conducting, an d an interm ediate sta te w ith high electrical resistance. A n evaporated silver film in the first sta te scatters little li g h t;

in th e interm ediate sta te i t scatters b rig h t orange yellow light, an d in the tw o-dim ensional gaseous sta te i t scatters b rig h t green lig h t.—J . S. G. T.

3 3 6

Metallurgical Abstracts

I I — PROPERTIES OF ALLOYS

(Continued from pp. 279-284.)

♦Creep Characteristics of Alumimum Alloys. R . R . K ennedy (A m er. Soc.

Test. M at. Preprint, 1935, Ju n e, 1-14).—A lum inium alloys are widely used in a variety of applications in w hich th ey are exposed to elevated tem peratures.

The short-tim e tensile properties a t these tem peratures have been stu d ied by a num ber of investigators, b u t little a tte n tio n has been p a id to th e long-tim e tensile properties or creep characteristics. N ine alum inium alloys th a t have been used or proposed for use a t elevated tem peratures were selected for investigation. The creep characteristics of these alloys were determ ined a t 400° an d 600° F . (205° and 315° C.). The creep rates of the alloys v aried over a wide range. Sand-cast alum inium -copper-nickel-m agnesium alloy h ad th e best creep characteristics of th e alloys tested. Some of th e new er w rought an d cast alloys were m arkedly inferior to th is alloy in th a t respect, although th e ir

1935

I I . — Properties o f Alloys 337

mechanical properties a t room tem perature were superior in some cases and they have b e tte r casting and forging properties. A bibliography of 9 refer­

ences is given.—S. G.

♦Effect of Composition on Mechanical Properties and Corrosion-Resistance of Some A l u m i n i u m Alloy Die-Castings. E . H . Dix, J r ., and J . J . Bowman (Metals Technology, 1935, 2, A.I.M .M .E. Tech. Publ. No. 616, 1-12). See Met. Abs., th is volume, p. 212.—W. H .-R .

♦Hardening Effects of Heat-Treatment on Aldrey-Type Light Alloys. Sakichi Kishino (N ippon Kwagalcu K w ai S h i (J. Chem. Soc. Japan), 1935, 56, 230-235;

C. Abs., 1935, 29, 3283).— [In Japanese.] W hen A ldrey in th e completely annealed state is heated above 350° 0., its hardness increases. This is owing to the solution of Mg2Si. W hen quenched A ldrey is heated, its hardness in ­ creases suddenly a t ab o u t 250° C. owing to the appearance of Mg2Si crystals.

From 250° to 450° C. the hardness decreases. Above 450° C. th e hardness increases owing to th e solution of Mg2Si. The d ilatatio n shows anomalies a t 250° and 450° C.—S. G.

♦On the Mechanism of the Ageing and Tempering of Quenched Aluminium Alloys. Takeo Takeuchi (J. M ining. Inst. Japan, 1932, 48, (569), 873-898;

Jap. J . Eng. Abs., 1935, 12, 54).— [In Japanese.] D ilatation, electrical resist­

ance, and hardness m easurem ents were carried o u t on quenched alum inium alloys containing copper or m agnesium and silicon. F rom these experim ents, T. concludes th a t the solute atom s in th e supersaturated solid solution are concentrated from place to place prio r to th eir precipitation as CuA12 or Mg2Si. This affects th e distortion of th e m other lattice, an d th e alloy is hardened. The d isto rtio n will reach its lim it, b u t slight heating causes soften­

ing by precipitation of th e compound. These phenom ena are repeated during th e tem pering and ageing of quenched alum inium alloys.—S. G.

♦Mechanical and Ageing Properties of Duralumin. Tsuneo W atase (Suiyd- kwai-Shi, 1932, 7, (38), 424rA31; Jap. J . Eng. Abs., 1935, 12, 55).— [In Japanese.] A nnealed an d cold-rolled, an d aged and cold-rolled m aterials were all hardened w ith increase in th e am ount of cold-work. The m aterial th a t had been cold-worked to the e x te n t of only a few % im m ediately after quenching was very i n f e r i o r i n mechanical properties, while th e effects of hardening were first observed after reduction of 10-12% . Age-hardening after cold-work was studied by m easurem ents of hardness an d electrical resistance. H ardening decreased w ith the am ount of cold-work. Severe-cold-work, e.g. 50-65% reduc­

tion, caused no more hardening after working.—S. G.

♦Investigation of the Al-Rich A l-Fe-Si System. H ideo N ishim ura (Tetsu-to- Hagane, 1932,18,849-860).— [In Japanese.] See a b stra c t from E nglish source, Met. Abs., th is volume, p. 147.—S. G.

♦The Constitution of the Antimony-Tin-Zinc Alloys. R o b ert Blondel and Paul Laffitte (Compt. rend., 1935, 200, 1472-1474).—-The alloys of th e anti- m ony-tin-zine system have been studied b y therm al analysis, taking recognized binary system s as bases. These la tte r were verified b y therm al analysis an d by m etallography, w hich established a range of tin-rich solid solutions in th e tin -zin c system , an d confirmed th e allotropic transform ation a t 325° C., an d th e com pound Sb2Sn3, observed b y Iw asA The therm al analysis of th e tern ary system was carried o u t in v ertical sections parallel to th e binary system tin -zin c, an d th e results are incorporated in a plane equilibrium diagram . Three tern ary peritectics were found, p x (antim ony 0-5, tin 91-5, zinc 8-0%), p 3 (antim ony 8, tin 91, zinc 1%) an d p 3 (antim ony 53, tin 40, zinc 7% ), giving rise to 3 transform ations : p 1 : liquid p t + ZnSb crystals ^ Zn crystals -f- c crystals a t 197-5° C .; p 3 : liquid p2 -j- b crystals c crystals + ZnSb crystals a t 235° C .; p 3 : liquid p 3 + a crystals ^ b crystals + c crystals a t 395° C. The crystals a, b, an d c correspond, respectively, to th e binary solution lim it a t 95% of antim ony, th e tern ary solution lim it a t 42% of antim ony (nearly Sb2Sn3), an d th e sum m it y of th e te rn a ry solid solution c

338 Metallurgical Abstracts

rich in tin . The m elting point of th e peritectic, p v was found b y differential analysis to be 197-5° C., higher th a n th a t of th e nearly b inary eutectic Sn-Z n (196° C.). The existence of th e tin-rich tern ary solid solution, c, w as con­

firmed b y m icro-exam ination and electrical-resistance m easurem ents of specimens annealed a t 150° C. for 11 days. The results seem to show th a t of all the compounds of zinc and antim ony, only ZnSb plays an y p a r t in the tern ary system , and is consequently th e only one stable in the presence of tin.

— J . H . W.

*0n Two Intermetallic Compounds of Beryllium with Iron. L. Misch (N aturwiss., 1935, 23, 287-288).—The beryllium -iron system contains a ferro-m agnetic phase FeB e2, the transform ation p o in t of w hich is 521°-524° C., an d th e direction of the strongest m agnetism in w hich is in th e hexagonal base. The phase has the MgZn2 stru ctu re w ith a = 4-212 an d c = 6-834 A .;

th e d is 4-65. A second com pound in th is system is FeB e5, w hich is non­

m agnetic a t ordinary tem perature b u t becomes so a t th e tem p eratu re of liquid air. I t has a body-centred cubic stru ctu re w ith a = 5-878 A. an d d = 3-17.

—B. Bl.

Aluminium-Bronze : Its Properties and Applications. --- (Metallnrqia, 1935,12, 35-37).—A discussion on th e composition, mechanical, an d corrosion- resisting properties of cast and hot-w orked “ alum inium -bronzes ” an d some of th e ir applications.—J . W . D.

*The Effect of a Third Element on the Ageing of a Binary System. I.—The System Copper-Aluminium-Nickel. V. G ridnev an d G. K urdjum ov (Domez, 1934, (11—12), 6 1-65; C. Abs., 1935, 29, 3635).— [In R ussian.] The addition of 2% nickel to th e system copper-alum inium raises th e eutectic from 570°

to 605° C. an d narrow s th e a-field from 9-8 to 8-6% alum inium . Below the eutectic no change of solubility of nickel w ith tem p eratu re was observed.

— S. G.

Cadmium-Copper for Overhead Lines. G. W . P resto n [Elect. Rev., 1935, 116, 372-373).—A brief review of th e m echanical a n d electrical properties of cadm ium -copper as used for electrical conductors.— S. Y. W .

*On Transitions in the CuAu Alloy.— II—III. W . S. Gorsky (Physilcal. Z.

Sowjetunion, 1934, 6, 69-76, 77-81).— [In English.] (II.— ) In continuation of previous w ork ( J . In s t. M etals, 1928, 40, 575), a n account is given of m easure­

m ents of th e velocity of tran sitio n of th e cry stal lattice of th e alloy CuAu to th e equilibrium state. The ra tio o/c of the cry stal lattice is expressed as a function of th e annealing period. No m athem atical form ula capable of expressing the results was found. (I I I .— ) The effect of strain , due to a change of the ax ial ra tio a/c, on equilibrium in th e ordered lattice of th e alloy is investigated m athem atically.—J . S. G. T.

Wrought Copper-Nickel 'Alloys. D . K . C ram pton an d H . P . Croft (Metals and Alloys, 1935, 6, 79—84).—R ecent w ork on new nickel—copper alloys is reviewed, an d th e properties of the 92 : 4 : 4 an d 91 : 7-5 : 1-5 copper-niclcel- alum inium are discussed. The m elting points are 1090° an d 1120° C., respec­

tively, an d th e m echanical properties are :

92 : 4: 4 Alloy. 91: 7-5:1-5 Alloy.

Annealed. Reduced 80%. Quenched. Precipitation- Hardened.

Tensile strength, lb./in.2 . Yield-point, lb./in.2 . Elongation, % Reduction in area, % Modulus of elasticity, X 106

45.000 20.000

00 80 21

120,000 80,000 12 50 18-5

48.000 30.000

50 80 21

110,000 80,000 10 35 18

1935

I I . — Properties of Alloys 339

B oth alloys can be hot-worked, welded, and brazed, and b o th have a good resistance to corrosion.—A. R . P .

*Some Tests on Tin-Bronzes at Elevated Temperatures. J . W . B olton (Amer. Soc. Test. M at. Preprint, 1935, Ju n e, 1-9).—The alloy specified in A.S.T.M. S tan d ard Specifications for Steam or Valve Bronze Sand-Castings (B—61), an essentially solid-solution structure, is shown to have a “ lim iting creep strength ”• of ab o u t 8000 lb./in.2 a t 500° F . (260° C.) an d to be free from em brittlem ent. A t 600° F . (316° C.), th e alloy has low “ creep-strength ” and is of low d uctility after exposure to this tem perature for long periods. The alloy specified in A.S.T.M. S tan d ard Specifications for Sand-Castings of the Alloy : Copper 88, T in 8, Zinc 4% (B-60) (the composition, copper 88, tin 10, zinc 2% , falling w ithin this specification is the one specifically referred to), consists of an essentially solid solution m atrix, throughout which a high tin component (the a -8 eutectoid) is dispersed in sm all particles. This alloy’s load-carrying characteristics a t 500° F . (260° C.) are inferior to those of alloy B-61, and there is evidence of em brittlem ent on exposure to a tem perature of 500° F. (260° C.). Microscopic study, especially of m aterial exposed to a tem perature of 600° F . (316° C.), shows clearly th a t this em brittlem ent is due to penetration or form ation of the brittle eutectoid stru ctu re along grain boundaries.—S. G.

♦Impact and Static Tensile Properties of Bolts [Steel, Monel Metal, Bronze, Brass]. H erbert L. W hittem ore, George W . N usbaum , and E dgar O. Seaquist (J. Res. N at. B ur. Stand., 1935, 14, 139-188; Research Paper No. 763).—This investigation was carried o u t to determ ine the properties of bolts under im pact tensile loading an d also und er static tensile loading. 360 specimens were tested, representing all possible com binations of 5 different m aterials (chrom- ium -nickel steel, cold-rolled steel, Monel m etal, bronze, and brass), 4 different bolt diam eters ( f , £ , | , f - in.), and 3 different forms of screw threads (American N ational coarse, American N ational fine, and D ardelet). These threads are often used by U.S. engineers for bolts. The U.S. S tan d ard threads are alm ost the same as the A m erican N ational coarse threads and the S.A.E. threads alm ost the same as th e A m erican N ational fine threads. The bolts of different d ia ­ m eters were geom etrically sim ilar, th e length betw een the head and the bearing face of th e n u t being 5 tim es the diam eter, th e th re a d extending inw ard from the face of th e n u t 1 diam eter. I n all cases th e im p act w ork for bolts w ith American N ational coarse threads was less th a n for bolts of th e same size and m aterial w ith A m erican N ational fine threads. E x cep t for the brass bolts and those cold-rolled steel bolts which showed b rittle failures, th e im p act w ork for bolts w ith American N ational fine threads was approxim ately th e same as for bolts of th e same size and m aterial w ith D ardelet threads. I n all cases th e im pact work for bolts w ith D ardelet threads was m uch greater th a n for bolts of the same size an d m aterial having American N atio n al coarse threads.

Sim ilar relations were observed for the sta tic w ork an d the m axim um static load. F o r bolts of the sam e size an d having the sam e th read s th e b o lt effi­

ciencies were approxim ately th e same for all of th e m aterials.—S. G.

♦Influence of Iron, Aluminium, and Silicon on the Impact Values of Brasses at Higher Temperatures. M asaichi N ishikaw a and E iichi Ito (Sniydkw ai-Shi, 1934, 8, 625-629; G. Ahs., 1935, 29, 3283).— [In Japanese.] Brasses were prepared containing 62-65% copper an d sm all am ounts of im purities of iron, alum inium , an d silicon less th a n 1% , and th e ir C harpy im p act values a t higher tem peratures were m easured. Iro n d id n o t have a g reat influence on the im p act value of these brasses, an d th ey showed m axim um im pact values a t 750°-850° C. according to th e copper content. A lum inium and silicon, however, h ad a m uch greater effect on th e im p act value, an d th e tem peratures showing th e m axim um im p act value were displaced to th e lower tem peratures 500°-700° C. an d 450°-650° C., respectively, in th e brasses

containing alum inium an d copper.— S. G,

340 Metallurgical A bstrads

♦Gold Cobalt Resistance Alloys. Jam es L. Thom as (J . Res. N at. B ur.

Stand., 1935, 14, 589-593; Research Paper No. 789).—-G old-cobalt alloys containing 0-75 to 5% cobalt were prepared an d investigated to determ ine if they are suitable for use in th e construction of electrical resistance standards.

The tem perature coeff. of electrical resistance of the alloys containing 1-5

to

2-5% cobalt is sm all a t room tem peratures, b u t th e therm oelectric pow er of the alloys against copper is large. These alloys were found to be inferior to gold-chrom ium alloys of ab o u t the same proportions.—S. G.

♦A Study of Lead Cable Alloys. H isakichi Sbim ba (Suiyokai-Shi, 1932, 7, (39), 432-443; Ja p . J . Eng. Ahs., 1935, 12, 55).— [In Japanese.] Tensile a n d bending tests were carried o u t on age-hardened lead cable alloys con­

taining antim ony, tin , an d calcium ; th e electrical an d fatigue properties were also measured. L ead alloys containing 1% antim ony should be quenched a t tem peratures above 225° C. for age-hardening. Air-cooling also causes hardening. The properties of lead alloys containing 0-96% calcium are greatly im proved by quenching in oil a t 100° C. from tem peratures of more th a n 235° C. The effects of th e addition of 0 -2 -l-5 % tin to lead alloys containing 0-04-0-08% calcium were exam ined. The stren g th of alloys ex tru d ed a t 255° C. is decreased b y th e ad d itio n of tin ; ageing a t 60° C., however, increases the stren g th to 600 kg./cm .2. A n alloy containing 1%

antim ony has superior fatigue properties to one containing 3% tin , while a lead alloy containing 0-04% calcium has far b e tte r fatigue properties. T en­

sile stren g th an d elastic lim it are m arkedly reduced by long loading, the lim it being 10% (15 kg./cm .2) of th e tensile strength. The fatigue failure of lead occurs a t the cry stal boundaries. W ork an d age-hardening increase the endurance lim it.—S. G.

*The Surface Tension of Molten Lead Alloys under Oxidizing Conditions.

H . Vance W hite (Metals and Alloys, 1935, 6, 53-56).—The surface tension of m onotype m etal containing lead 76-5, an tim ony 16-5, an d tin 7% is reduced by 30% by ad d itio n of 0-05% of sodium an d increased b y 28% b y addition of 0-2% of zinc. Potassium an d cadm ium increase the surface tension by about 4 % . A ddition of sodium to lead is ju s t as satisfactory as addition of arsenic for m aking spherical shot, b u t i t has practically no hardening effect.—A. R . P.

♦Bearing Analysis Determines Permissible Speeds. W illiam A. Rowe (Machine Design, 1935, 7, (1), 30—32).—T he value of th e following bearing m etals for use in centrifugal fans has been exam ined : (A) lead 75-7, tin 11-6, antim ony 12-2, copper 0-5% ; (B ) lead 50, tin 38, antim ony 11-5, copper 0-5% ; (C) tin 89-5, antim ony 7-5, copper 3% . I n all cases the increase in tem perature a t journal velocities (F ) of 10^10 ft./second has been p lo tte d against P V , where P is th e u n it pressure p er in .2 of projected area. W ith V n o t exceeding 20 ft./second A gives th e best results, b u t B is satisfactory up to V = 30 ft./

second. A t higher values of V the tin-base alloy C is m uch superior to the others. The best criterion for evaluating th e perform ance of a bearing m etal is considered to be the value of P F 2 for a definite rise in tem perature. F or an increase of 70° F. (39° C.) P F 2 = 9000 for A , 24,000 for B , an d 18,000 for C. These figures show th a t alloy B m ay be used as a su b stitu te fo r th e expensive tin-base alloys w hen F does n o t exceed 30 ft./second.—A. R . P .

♦The Constitution of the Lithium-Bismuth Alloys. (Zintl an d B rauer.) See p. 343.

♦The Constitution of the Lithium-Cadmium Alloys. (Zintl a n d Schneider.)

See p. 343. ’

♦On the Equilibrium Diagram of the Magnesium-Zinc-Tin System Bun- ta ro O tani (Tetsu-to-Hagane, 1933, 19, (7), 566-572; Ja p . J . Eng. A hs., 1935, 13, 62).— [In Japanese.] The te rn a ry diagram of th e m ag n esiu m -zin c-tin system was investigated by therm al an d microscopic analyses. I t was found

1935

I I . — Properties o f Alloys 341

to consist of 12 prim ary crystallization surfaces, 15 u n iv arian t lines, and invariant points. The in v arian t points are sum marized as follows :

Mg.

Composition.

Zn. Sn.

Temperature,

"C.

Reaction.

2 6 92 175 Liq = Zn -)- Sn -f- e

4 88 8 346 Liq = Zn + e -+- s

4-5 87-3 8-2 354 Liq + y — s + e

45 53 2 351 Liq + V = / + €

46-3 53-2 0-5 340 Liq = y' + « +

s

46-3 53-2 0-5 340 Liq = v + v ' + *

—S. G.

♦Working Properties of Magnesium Alloys. Shiro Ishida (Tetsu-to-Hagane, 1932, 18, 705-742; Jap. J . Eng. Abs., 1935, 12, 52).— [In Japanese.] The cold- and hot-working properties of alloys of magnesium w ith alum inium and zinc were studied. I t is concluded th a t magnesium alloys should be hot- rolled a t 300° C., th e tem perature of th e rolls being m aintained a t 250°- 300° C. Magnesium alloys containing up to 7% alum inium an d m agnesium - zinc alloys w ith up to 5% zinc can be hot-rolled; th e m axim um lim it of cold-rolling being a reduction of 10%. The tensile stren g th of m agnesium alloys is n o t increased by cold-work so m uch as h ard n ess; elongation and reduction of area are decreased. The tem perature of recrystallization was found, by th e X -ray m ethod, to be 170°-200° C .; annealing should be carried o u t a t 300° C. Of the m etals zinc, manganese, beryllium , cadm ium , &c., zinc and manganese affest th e w orking properties of m agnesium -alum inium alloys more favourably th a n th e others.—S. G.

♦Electrosynthesis of Silver, Tin, and Zinc Amalgams, and Their Chemical Structure. K azim ierz Duezko ( Wiadomości Farm ., 1934, 61, 633-636, 667- 671, 683-686, 698-700 (700 in G erm an); G. Abs., 1935, 29, 2859).—The amalgams are prepared by th e modified electrosynthetic m ethod of K erp (Z. Elektrochem., 1898, 3, 308) and b y m ixing electrolytically dispersed silver w ith mercury. The silver amalgams differ in hardness, electrical conductivity, and electrode potential, depending on th e m ethod of preparation, an d m ust be regarded, therefore, as different substances. On th e basis of th eir m ercury % content, th eir volum e changes, specific conductivity, electrode potential, and photom icrographs, these am algams are classed as binary alloys showing a crystallographic stru ctu re and possessing AgHg as th e sim plest chemical com­

pound. T in amalgams are crystalline chemical com pounds of th e form ula Sn7H g w ith a volum e increase of 8 % ; th ey can exist in an equilibrium w ith free m ercury. Zinc am algams represent a common physical m ixture as has been reported b y P uschin (Z. anorg. Chem., 1903, 36).— S. G.

♦Intermetallic Compounds Formed in Mercury. V.— Compounds in the Zn-Mn, Zn-Co, Zn-Ni, A l-Fe, Sn-Mn, and Sn-Co Systems. A lexander S.

Russell, T. R . K ennedy, an d R . P . Lawrence (J. Chem. Soc., 1934, 1750-1754).

— A num ber of compounds, including some new ones, has been found by th e m ercury m ethod. The em pirical formulae agree w ith those obtained by therm al and X -rays m ethods.— S. V. W.

♦Aluminium-Copper-Nickel Alloys of High Tensile Strength Subject to Heat-Treatment. W . A. Mudge an d P au l D . Merica (Metals Technology, 1935, 2, A.I.M .M .E. Tech. Publ. No. 619, 1-12).—A brief description of the m echanical properties of “ alum inium -M onel m e ta l11 m ade by adding 4% alum inium to ordinary Monel m etal containing a b o u t 68% nickel; d a ta

342 Metallurgical Abstracts

for o th er alum inium -copper-nickel alloys are also given. These alloys are soft and ductile when quenched from 1200° F . (649° C.) or above, th e m axim um softness occurring after quenching a t or above 1500° F . (815° C.). On slow cooling from tem peratures betw een 1200° an d 2100° F . (649° an d 1148° C.), they become h ard, w ith high tensile strength and m oderate ductility. Tensile strengths of th e order 100,000 to 150,000 lb ./in .2 can be obtained, w ith elongation values betw een 15 an d 30% . B oth th e soft an d th e h a rd forms of th e alloy appear as homogeneous solid solutions w hen exam ined m icro­

scopically, and the n atu re of th e transform ation is unknow n. T he corrosion- resistance of th e “ alum inium -M onel m e ta l” is sim ilar to , o r slightly b etter th a n th a t of o rdinary Monel m etal.—W. H .-R .

*Influence of Stress on the Magnetic Properties of Super-Permalloy. Masaru F u k u d a an d R yôtarô N om iyam a {Bull. Tokyo Univ. Eng., 1933, 2, (7), 396- 398; Jap. J . Eng. Abs., 1935, 13, 43).— [In Japanese.] The influence of m echanical stresses on th e perm eability of iro n alloys of high perm eability was investigated as a m a tte r of technical as well as scientific interest. The paper also deals w ith the m agnetic skin effect of th e alloys.— S. G.

*The Ferromagnetism of the Platinum-Chromium Alloys. E . Friederich an d A. K ussm ann (P hysikal. Z ., 1935, 36, 185-192).—The region of composi­

tio n w ithin w hich th e platinum -chrom ium alloys are ferrom agnetic extends from 7 to 20% chrom ium ; th e corresponding atom ic-% of chrom ium are 22- 48-5%. Magnetic satu ratio n in th e case of the alloy containing ab o u t 10%

chrom ium (30 atom ic-% ) corresponds to a field-strength of ab o u t 3000 c.g.s.

units. M icrographie an d X -ray investigations show th a t crystalline super­

stru ctu re, based on th e presence of a com pound, ap p aren tly P tC r3, is present in th e ferrom agnetic alloys an d extends to high chrom ium content, an d th a t the ferrom agnetic range is entirely a tran sitio n region.—J . S. G. T.

*Reactions in Solid Metallic Systems [Silver-Aluminium Alloys]. André H one {Rev. trimest. canad., 1934, 20, 376-391 ; C. A bs., 1935, 29, 3209).—•

The v ariatio n of electrical conductivity w ith tim e was m easured for alloys of silver containing 38-00, 28-45, 19-85, 11-18, an d 4-78% alum inium , a t const, tem peratures of 331°, 304°, 265°, an d 220° C. A m athem atical developm ent, based on th e kinetic theory of gases, is presented to explain th e course of decomposition of th e alloys. T he “ energies of activ atio n ” for th e reaction 8 -phase >- y -phase are for the conditions of tem p eratu re used 22-0, 22-6, 25-6, 15-7, an d 9-3 cal./grm . mol., respectively, for th e alloys in th e order given above.—S. G.

Special Alloys. ——- (Oiesserei-Praxis, 1935, 56, 36, 37, 100, 122).— See also M et. A bs., 1934,1, 125,172, 346, 495, 575, a n d th is volum e, p. 219. [Note : I t seems th a t th is list of alloys will continue to ap p ear in alphabetical order ; th e continuations of th e series will n o t be referred to in M et. A&s.] The com position an d some properties an d applications are given fo r: Forbe’s m etal, F ra ry m etal, F o n tan e’s m etal, F ra ry lig h t m etal, F ricke’s new silver (nickel-brass), F risch m u t alum inium solder, Gedge’s brass, Gemma bearing m etal, genuine B a b b itt, G erm ania w hite bronze, Genelit, G lievor bearing m etal, gold-copper, an d G iuschi-Buischi.—J . H . W.

III.— STRUCTURE

(M etallography; M acrography; C rystal S tructure.)

(Continued from pp. 284-291.)

f Preparation of Lead and Lead-Rich Alloys for Microscopic Examination.

W . H . B assett, J r ., an d C. J . Snyder {Metals and Alloys, 1935, 6, 125-129).—

R ecent m ethods for preparing sections of lead alloys for micrographie exam ina­

tio n are reviewed, an d th e sphere of usefulness of 8 etching reagents is indicated.

C haracteristic photom icrographs of num erous alloys are shown.—A. R . P .

1935

I I I . — Structure 343

Mounting Concentrates and Tailings for Microscopic Study. P au l H . B ird (Eng. and M in . J ., 1935, 136, 233-234).—W hilst m ainly directed tow ards the m ounting of geological specimens, th e m ethods suggested m ight he employed in m etallurgical work. Synthetic resins, such as Bakelite, are used as th e cem enting m edia.—R . Gr.

*Melting of Metal Crystals at Their Boundaries, and a Theory of Recrystal­

lization. U saburo Y oshida an d K azuo K oyanagi (M em. Coll. Sci. Kyoto Im p . Univ., 1935, [A], 18, 9-16).— [In English.] I t is found th a t when the te m ­ perature of a m etal is increased to a value ju s t below its m elting point, the m etal m elts a t its crystal boundaries. On th e assum ption th a t th e m etal melts a t its crystal boundaries a t its recrystallization tem perature, a theory of the recrystallization of m etals is proposed.—S. G.

The Structure of Metallic Coatings, Films, and Surfaces. (M etal­

lurgist (Suppt. to Engineer), 1935, 10, 22-24).—A review of a General D iscus­

sion held b y th e F arad ay Society; see M et. Abs., th is volume, pp. 284-289.

—R. G.

*Structure and Properties of Nickel Deposited at High Current Densities.

W illiam Blum and Charles K asper (M onthly Rev. Am er. Electroplaters' Soc., 1935, 22, (5), 19-30).—See M et. A bs., th is volume, p. 287.—A . R . P.

*X-Ray Studies of the System Iron-Chromium-Nitrogen. Sten Eriksson (Jernkontorets A n n ., 1934, 118, 530-543; C. Abs., 1935, 29, 2829).—Ir o n - chromium nitrides were prepared by passing N H 3 over th e heated alloys. An interm ediary phase (a') of th e form ula FeCr was confirmed, and is probably to be considered a deformed a lattice. The sym m etry, however, is low and either tri- or mono-clinic. I n the chrom ium -nitrogen system th e hexagonal [1-phase has a “ super stru ctu re,” w ith a volum e 3 tim es th a t of th e close- packed hexagonal lattice. The length of th e c axis is th e same for b o th cells b u t th a t of th e a axis is T732 tim es th a t of th e close-packed lattice. The homogeneity lim its are 11-9-9-3% nitrogen. The dim ensions range from a = 4-750 A. (2-742 A.), c = 4-429 A. (4-429 A.) and c/a = 0-933 (1-615) a t the lower lim it to a = 4-796 A. (2-769 A.), c = 4-470 A. (4-470 A.) an d c/a = 0-932 (1-614) a t th e upper lim it, th e num bers in parentheses referring to th e hexagonal close-packed cell.— S. G.

The Alpha-Phase Boundary in the Copper-Tin System. —— (Metallurgist (Suppt. to Engineer), 1 9 35,10, 30-32).—A sum m ary an d discussion of a paper by T. Isaw a an d I . O binata on “ X -R ay Investigations on T in-B ronzes,”

Metallwirlschaft, 1935, 14, 185-188; see M et. Abs., th is volume, pp. 56, 289.

—R . G.

*The Constitution of the Lithium-Bismuth Alloys. E . Z intl an d G. B rauer (Z. Elektrochem., 1935, 41, 297-303).—In agreem ent w ith th e results of therm al analysis an d conductivity m easurem ents of G rube, Vosskiihler, an d Schlecht, 2 stable interm ediate phases were found b y X -ray analysis in th is system a t ordinary tem peratures. T hey contain 50 (a-LiBi) an d 75 atom ic-%

of lithium (Li3Bi), an d have a range of hom ogeneity of undetectable dimensions. L i3B i is cubic (a = 6-708 A.) w ith 16 atom s per cell; face- centred lattices begin a t 0 0 0 (Bi), \ \ \ , j- \ \ , f f f (Li). a-LiB i has a te tr a ­ gonal space-centred stru ctu re like th e previously described N aBi, w ith a = 3-361 A., c = 4-247 A., c/a = 1-264; B i in 0 0 0, L i in ^ J J. The tetrag o n al lattices of a-LiB i an d N aB i arise from th e [f-brass lattice b y distortion, in which th e bism uth atom s are bro u g h t together in planes parallel to th e basic plane b y m u tu al contact.—J . H . W.

*The Constitution of the Lithium-Cadmium Alloys. E . Z intl an d A.

Schneider (Z. Elektrochem., 1935, 41, 294r-297).— The existence of 4 in te r­

m ediate forms of crystals has been found in th e lithium -cadm ium system by X -ray analysis, in agreem ent w ith th e therm al analysis an d conductivity an d dilatom etric m easurem ents of G rube, Vosskiihler, an d Vogt. One of these

344 Metallurgical Abstracts

phases (¡3) exists only a t higher tem peratures an d has possibly cubic sym m etry. The p' phase, w ith range of homogeneity ab o u t 25 atom ic-

% of lithium , corresponding to th e form ula LiCd3, has the ^ o s t c ose y- packed hexagonal stru ctu re (a = 3-083 A., c = 4-889 A., c/a == 1-586, 2 a °m s p er cell), w ith static distribution. The m ixture-phase (Mischungsstucke) betw een an d cadm ium satu rate d w ith lithium (a-phase) shows tw o different ty p es of hexagonal packing, th e axial ra tio of th e one being over 1-8, and t h a t of th e o th e r being 1-63 (the ideal ra tio of th e closest spherical packing).

The y-phase (LiCd) has a space-centred stru ctu re of th e N aT l ty p e (a = 6-687 A.). Alloys w ith a lithium co n ten t of ab o u t 75 atom ic-% consist of crystals (■/') w ith a face-centred cubic lattice an d sta tic atom ic arrangem ent (a = 4-250 A.).—J . H . W.

*A Manganese-Silicon Alloy with the Tungsten (A2) Type of Structure.

F ritz Laves (Z . K rist., 1934, 89, 189-191).—B oren {Met. A bs., 1934, 1, 178), who w orked w ith pure vacuum -distilled m anganese, found X -ray evidence for th e com pounds Mn3Si an d MnSi, b u t n o t for the ad d itio n al com pound Mn5Si3 claim ed by Vogel an d BedarfE (M et. A bs., 1934,1, 295), who exam ined less pure alloys by therm al an d microscopic m ethods. The alloys used b y Vogel and Bedarff have been exam ined by X -ray crystal analysis, w hich shows th a t the M n5Si3 phase of Vogel and Bedarff is identical in stru ctu re w ith th e M n3Si phase of B oren, w hich is hexagonal. The M n3Si phase of Vogel an d Bedarff has a body-centred cubic lattice w ith a = 2-85 ± 0-01 A., an d a random d istrib u tio n of atom s. These discrepancies are probably due to th e im purity (about 3% , chiefly oxide, iron, an d alum inium ) in th e alloys of Vogel and Bedarff.—W . H .-R .

The Nature of Twinning Planes. E . G. Ananiaschw ili an d D. B. Gogo- beridse (Physihal. Z. Sowjetunion, 1934, 6, 184r-185).— [In G erm an.] I t is suggested th a t in th e process of tw inning th e cry stal lattice is n o t m aterially altered, an d th a t v ery fine crystalline m aterial is present in interstices between the tw ins.—J . S. G. T.

t*The Mechanical Properties and the Real Structure of Crystals. E . Orowan (Z. K rist., 1934, 89, 327-343).—The discrepancies betw een th e theoretical and actu a l strengths of crystals are described, an d th e different theories discussed critically. M any examples of th e g re a t effect of surface cracks or flaws are described, a n d i t is shown how weakness in plastic deform ation can be accounted for w ith o u t assuming th e existence of a very deep crack. 0 . concludes th a t theories of secondary mosaic or block stru ctu res are u n ­ necessary, an d th a t all th e effects can be ascribed to th e presence of flaws.

—W . H .-R .

♦New Evidence, Setting an Upper Limit of 500 A. or Less, to Dimensions of Mosaic Blocks (if Any) in a Crystal. H arold E . Buckley (Z. K rist., 1934, 89, 41CMT5).— [In English.] O ptical interference effects have been observed for lig h t reflected betw een th e opposite parallel faces of m any crystals, an d these require a degree of perfection w hich is difficult to reconcile w ith th e existence of block structures w ith dimensions of th e order 10,000 A. B. concludes th a t a block stru ctu re is n o t a fundam ental characteristic of a crystal.—W . H .-R .

fThe Theory of Real Crystals. Adolf Sm ekal (Z. K rist., 1934, 89, 386-399).

—-A review of experim ents on th e structure-sensitive properties of crystals, especially of rock-salts, an d of S.’s theories of flaws in crystals.—-W. H .-R .

fSome Applications of X-Ray Crystallography to Industry. J . T. R andall and H . P . R ooksby (G.E.C. Journal, 1934, 5, 189-196).—The underlying principles of th e subject are briefly explained, an d illustrations are given of in d u strial applications covering such subjects as th e behaviour of refractory m aterials, m anufacture of glass, wire-drawing, radio valves, an d h o t cathode discharge tubes.—S. V. W.

1935

I V . — Corrosion 345

I V — CORROSION

(Continued from pp. 291-296.)

What May Not Be Made With Aluminium? R ichard Schulze ( R .T .A . Nachr., 1935, 15, (21), 3-1).—P ure alum inium m ay be distinguished irom alum inium alloys by dipping the m etal in 10-20% caustic soda. The con­

ditions in which alum inium should n o t be w orked into tubes, arm atures, screwed joints, &c., because of th e danger of corrosion, are discussed^ ^

fBasic Copper Carbonate and Green Patina. W. H . J . V ernon (J. Chem.

Soc., 1934, 1853-1859).— S. V. W.

*On Hardenable Bronzes on a Nickel-Copper-Tm Base. IV.—Influence of Precipitation-Hardening on the Resistance to Corrosion. E . F etz (Korrosion u. Metallschutz, 1935, 11, 100-107).—The resistance to corrosion of copper- rich alloys containing nickel an d tin has been determ ined i n 3 / 0 nitric acid, and in 3 an d 10% hydrochloric acid after different heat-treatm en ts and m conditions of to ta l im mersion w ith free access of a ir in statio n ary media.

The rate of dissolution of precipitation-hardened alloys in nitric acid is greater the greater is the am ount of th e new phase precipitated in a highly dispersed form ; w ith progressive coagulation of th e disperse phase the resistance to corrosion approaches th a t of the annealed m etal. I n 3% hydrochloric acid the hardened alloys become coated w ith a com pact protective layer w hich reduces the ra te of a tta c k below th a t of homogenized allo y s; a sim ilar effect is obtained in 10% hydrochloric acid, b u t th e protective layer is n o t so adherent.

The presence of oxidizing agents accelerates corrosion in hydrochloric acid.

Annealed alloys of the tern ary system show approxim ately th e same resistance to corrosion as th e binary alloy of copper and the predom inating elem ent;

w ith increase in nickel content th e resistance to nitric acid decreases an d th a t to hydrochloric acid increases. No appreciable deterioration of th e m echam cal properties of th e 7 - 5 : 8 : 86-5 n ickel-tin-copper alloy occurs a fter exposure for a m onth to running aerated sea-w ater under static loads. A . K . Jr.

♦The Electrolytic Corrosion of Lead Cable-Sheath. Masaie H orioka and Takao K yogoku (J. Inst. Teleg. Teleph. Eng. Japan , 1932, (106), 37-57).— [In Japanese.] See Met. Abs. (J . In st. Metals), 1933, 53, 21.—-S. .

♦A Simple Method for Determining the Electrolysis of Lead Cable. Masaie Horioka an d Takao K yogoku (J. In st. Teleg. Teleph. Eng. dapan, 1932, (107), 254—257; Jap. J . Eng. Abs., 1935, 12, 30).— [In Japanese.] Chemical a n a ­ lyses were carried o u t to ascertain w hether the corrosion of lead cable-sheath is or is n o t due to electrolysis, and also to te s t the presence of lead peroxide on th e cable surface. Chemical analysis in th is field is difficidt. Since in m ost electro­

lysis surveys qualitative analysis is sufficient, a very simple m ethod was devised, in which a n acetic acid solution of te tra m e th y l y-p'-diam inophenyl-m ethane is poured over the lead surface, w hen the presence of lead peroxide is clearly indicated by a deep blue colour. The same resu lt m ay be obtained w ith an acetic acid solution of benzidin N H 2-C6H 4-C6H 4-NH2. These solutions also indicate, by colouring, traces of lead ions in the soil around th e concrete duct, through which the lead ions ooze o u t by electrolysis into th e surrounding soil, th u s rendering it possible to obtain, from outside, a rough idea of electrolysis of the cable-sheath enclosed in th e concrete duct. -S. G.

On the Corrosion of Type Metal in Contact with Red Beechwood. Kruno Schulze (Z. dent. Buchdrucker verwandte Gewerbe, 1934, 46, 880-881; Chem.

Zentr., 1935, 106, I , 786).—Type m etal stored in red beechwood boxes fre­

quently becomes severely corroded, especially if th e boxes are new. This is a ttrib u te d to vapours of volatile organic acids, probably acetic acid, evolved from th e wood.—A. R . R.

346 Metallurgical Abstracts

*On the Topochemistry of Metallic Magnesium (A Contribution to the Know­

ledge of Metallic Corrosion). A ntonín Vyskocil (Ghem. L isty, 1934, 28, (15- 16), 201-207).—See M et. Abs., 1934, 1, 303.— R. P.

The Corrosion of Magnesium. L. W h itb y (Korrosion u. Metallschutz, 1935, 11, 88-89).—Polem ical against K roenig an d P avlov (cf. M et. A bs., th is volume, p. 60). The statem en t th a t hydrogen is evolved from inclusions in m ag­

nesium alloys during corrosion is co ntradicted by th e w ork of V ernon and W hitby. The protective action of m anganese in magnesium alloys is a tt r i­

b u ted to the form ation of films w ith a high cathodic overvoltage an d n o t to the form ation of protective films w ith a high co n ten t of m anganese hydroxide.

—A. R . P.

On the Corrosion of Magnesium Containing Manganese. W . K roenig and S. Pavlov (Korrosion u. Metallschutz, 1935, 11, 89).—A reply to W hitby (preceding abstract). K . an d P . m ain tain th e ir previous in terp re tatio n of the observed phenom ena.—A. R . P .

In con el: An Alloy for Textile Wet-Processing Equipment. P . L. L a Que (Amer. D yestuff Reporter, 1935, 2 4 ,114—119; C. Abs., 1935, 29, 3284).—Inconel contains (approxim ately) nickel 80, chrom ium 14, an d iro n 6% , an d is resistant to a very wide v ariety of acid an d alkali corrosives. M echanical and physical properties of the alloy are tab u lated , an d also the rates of corrosion in h y d ro ­ chloric, sulphuric, an d n itric acid solutions of various strengths. H ypo­

chlorite solutions are less corrosive to Inconel th a n to Monel m etal, though it should n o t be used in continuous co n tac t w ith chlorine bleaching solutions of an y strength.— S. G.

*The Properties of Zinc of Exceptional Purity Compared with those of Other Specimens of Zinc. Louis B ouchet (Compt. rend., 1935, 200, 1535-1537).—

A com parison has been m ade experim entally betw een th e action of redistilled w ater an d chemically pure acid solutions on a specimen of very pure zinc containing, according to spectroscopic analysis, n o t more th a n 0-0001% of im purities, w ith th a t on o th er specimens of fineness from commercial p u rity up to 99-995%. (1) 15% hydrochloric a c id : after im m ersion for 5 hrs., th e p u rest zinc lost 2-2% of its w eight, th e loss increasing w ith th e am o u n t of im p u rity up to 25% for 99-978% zinc ; (2) 20% sulphuric a c i d : th e action was sim ilar, b u t to a sm aller e x te n t; (3) concentrated n itric acid (40° B e ): the e x tra pure zinc rapidly dissolved w ith the evolution of copious n itrous fumes, while com m ercial zinc lost only .(

of its w eight in 10 m in u te s ; (4) redistilled w ater (conductivity = 0 - 9 5 x 1 0 '6, Pu = 5-9): the e x tra pure zinc ap peared to increase slightly in w eight, b u t th is m ay have been due to experim ental e rro rs; th e other specimens all corroded in the same m an n er as (1) an d (2), b u t to a sm aller extent. The action of nitric acid can be explained by the tendency of certain im purities to cause passivity, an d by secondary reactions w hich m ay be represented by th e e q u atio n : 9 H N 0 3 + 4Zn = 4 Z n (N 0 3)2 + 3H 20 + N H 3. I t should be possible to estim ate the am o u n t of im purities in zinc by th e ra te of solution of the m etal in the ap p ro p riate liquid.

—J . H . W.

Tube Corrosion. F . J . Bullen (Metallurgist (Suppt. to Engineer), 1934, 9, 183—186).—-See also M et. . 1 bs.., th is volume, p. 162. Cases of corrosion are described in which the perforation of tubes was a ttrib u ta b le to the presence of oil inside. I n one case th e same ty p e of tu b e h a d been used in condensers in the sam e power statio n w ith success, an d th e reason for its failure in an oil cooler (coolmg w ater inside) was obscure u n til ex tractio n of th e scale deposit w ith eth er showed the existence of oil. The fau lty fitting of th e tube in th e end-plates h ad been initially responsible for the failures. The effect of a drop of oil settling on the tu b e surface is to set u p corrosion b y differential

1935

I V . — Corrosion 347

aeration. This was confirmed by laboratory experim ents. Sim ilar features were shown by tubes from an oil-tanker, an d in the case of failures occurring in m otor lifeboats the introduction of oil was traced to th e im pregnation of the tape w ith oil prior to packing. Oil was th u s present in the w ater outside the tubes and tended to settle on the to p surface. Illustrations of corroded tubes are shown. The detection of oil as th e direct cause of tu b e failures is seldom easy, b u t it m ay exist long enough to in itiate local corrosion which then proceeds independently.—R . G.

♦The Control of Corrosion in Air-Conditioning Equipment by Chemical Methods. C. M. Sterne (Amer. Soc. Test. M at. Preprint, 1935, Ju n e, 1-10).—

Corrosion a tta c k of the metallic p arts of air-conditioning system s can be so severe th a t perforation of ferrous sheets and pipes m ay take place in as sh o rt a tim e as 4 m onths if the w ash w ater or condenser w ater is n o t chemically treated . Practically every type of corrosion a tta c k is common to these system s. Service corrosion tests and analyses of the recirculated w ater show very clearly the causes and degree of severity of th a t attack . The tests also show th e degree of protection th a t m ay be obtained by proper chemical treatm en t. S. has carried out corrosion tests in over 200 separate air-conditioning systems, handling both comfort and industrial conditioned spaces in m any types of ind u stry an d in various cities throughout th e U nited S ta te s ; representative cases are reported in this paper. Check exam inations of these system s by the au th o r an d others have shown conclusively th a t by proper chemical tre a tm e n t and supervision the corrosion a tta c k m ay be reduced to a m inim um .— S. G.

♦Propeller Cavitation. Y oshiyuki A m ari (Journal of Zosen K iokai (Soc.

Naval Arch. Japan), 1932, 4 9 ,153-161).— [In Japanese.] A fter discussing the causes and n atu re of the various kinds of cavitation of m arine screw propellers, A. describes his own m ethod for dealing w ith the effect of cavitation on propeller design. The principle of th e “ th r u s t indicator,” w hich is th e m ost convenient apparatus for the stu d y of the cavitation problem , is explained.

Some results of experim ents on cavitation are given in th e appendices to th e paper.—S. G.

♦The E.M.F. Between Metals in Sea-Water. J . W. W illstrop (Aeronaut.

Res. Cttee., R . and M . No. 1611, 1934, 9 p p . ; an d (sum m ary) Light M etals Research, 1935, 3, 340-342).—The potentials of various m etals and alloys against the A-calom el electrode in sea-w ater have been determ ined a t 25°

and 40° C. 18 : 8 chrom ium -nickel steel an d Monel m etal have the m ost positive potentials, an d these are followed in order by brasses an d bronzes, D uralum in, and copper-alum inium alloys, ordinary steels, alum inium alloys free from copper, cadm ium , zinc, an d magnesium .—A. R . P .

Corrosion-Testing Methods. H . E . Searle an d F . L. L a Que (Am er. Soc.

Test. M at. Preprint, 1935, Ju n e, 1-12).—A tten tio n is directed to th e practical advantages of field corrosion te sts as a n aid in selecting m aterials to be used in equipm ent th a t m ust resist corrosion. A simple an d inexpensive device is described th a t has broad application in field corrosion testing. B ased on 8 years of experience in the use of th is an d o th er devices, i t is considered to be the m ost practical y e t developed. Exam ples are given to illustrate the accuracy w ith w hich perform ance in service has been predicted thro u g h its use. I t is suggested th a t standardization of ap p aratu s for field corrosion te s t­

ing will be of greater u tility th a n a sim ilar standardization of laboratory testing equipm ent.—S. G.

C O R R O S I O N -R E S IS T A N T M A T E R I A L S .

Materials Recommended for Oil-Refinery Pumps. A. E . H arnsberger (Chem. and M et. Eng., 1935, 42, 144-145).—Bronze is used fo r casings an d impellers of centrifugal reflux pum ps in severe corrosive conditions, an d for casing w earing rings, in ad d itio n to Monel m etal an d S tellited steel. H ard ,