METALLURGICAL A B STRA CTS
(G E N E R A L A N D N O N -F E R R O U S )
Y o l u m e 3 1 9 3 6 P a r t 13
I.— P R O P E R T IE S OF M ETALS
(C o n tin u cd fro m p p . -187-503.)
♦M echanical Properties of A lum inium and Its Alloys A fter Prolonged H eating.
A. von Z eerleder a n d R . Irin a m i (./. In s t. M etals, 1936, 59, 111-124; d is
cussion, 125-127).—Tho stre n g th o f pu re alum inium a n d yario u s alum inium alloys w as in v cstig atcd a fte r h eatin g for long periods a t 75°-300° C. T he stre n g th p ro p ertie s o f th e sam e m aterials w ere d eterm ined also in th e sta to o f com plete stabilization. T he h eatin g periods em ployed cxtended ovcr approxi- m ately 2 years. A fte r tre a tm e n ts o f different d u ra tio n a t elevatcd tem pora- tu res, som e specim ens were coolcd a n d te s te d a t room te m p e r a tu r e ; others were te s te d a t th e tr e a tm e n t te m p e ra tu re . F o r com plete softening a t 250° C., for instance, to o b ta in th e p ro p erties observed in com pletely stabilizcd sam ples, h eatin g periods o f a t le a st 6 m o n th s are required in tho case o f puro alum inium a n d A nticorodal, an d o f m ore th a n 2 y ears for A vional a n d “ Y ” alloy. A still longer h e atin g tim e is necessary in th e case o f th e alloy
“ R .R . 59.” T o determ ino th e decrease in stre n g th o f a n y m a te ria ł a fte r heatin g for long periods a t elev a ted te m p eratu res i t is necessary, therefore, to carry o u t te s ts o f long d u ratio n . T he values o f th e yield -p o in t observed in th e norm al sh o rt tim e te s t a fte r h e atin g periods o f 1 y e a r form a basis for calcula- tions for engineers. T he perm issible loads can be fo u n d only by obseryation of th e creep lim it, a n d th is p ro p e rty is being stu d ied b y th e a u th o rs.—A. v. Z.
♦The Conductivity of S uper-Purity A lu m in iu m : The Influence of Smali M etallic Additions. G aston G. G au th ier (J. In s t. M etals, 1936, 59, 129—
146; discussion, 147-150).— T his p ap er deals w ith th e effect on th e con- d u c tiv ity o f su p e r-p u rity alum inium (excecding 99-99% ) o f ad d itio n s o f those elem ents w hich m ay occur as im p u rities in com m ercial alum inium . I t is show n t h a t alum inium follows th e uniyersal law t h a t th e co n d u ctiv ity a n d the te m p e ra tu re coeff. o f co n d u ctiv ity b o th increase w ith tho p u r i t y : M atthicssen’s Law has been confirm ed. T he d a ta p resented in th is p a p e r on tho effect o f sm ali ad d itio n s on th e c o n d u c tm ty o f alum inium aro o f valuo in t h a t th e y have been determ ined u n d er favourable experim cntal conditions, owing to tho ex trem e p u rity o f th e basis m etal an d tho large a m o u n t w hich has been available. T his high p u rity lias m ade i t possible to determ ine, w ith a s ta te d aceuracy, th e effect o f each one o f th e ad d ed elem ents in th e alm o st com pleto absence o f o th e r i m p u r i t i e s . F u rth e r, th e f i g u r e s g i v e n f o r i r o n an d S il ic o n ,
for these elem ents w ith tita n iu m a n d v an ad iu m , a n d for m agnesium a n d Silicon, m ake i t possible to calculate th e c o n d u c tm ty o f aluminium o f accur- a te ly know n p u rity . N o rb u ry ’s L aw docs n o t a p p e a r to hołd in th e case o f alum inium .— G. G. G.
The Influence of Therm al Expansion on the Electrical R esistance of Con- ductors, and its Influence on M easurem ents of T em perature-R esistivity Coefficients [of A lum inium ]. O. S carp a (A llu m in io , 1934, 3, (2), 63).— T he erro r in tro d u ced in to determ in atio n s o f th e te m p e ra tu ro -r e s is tm ty coeff.
o f alum inium by th e th e rm a l expansion o f th e m a te ria ł is show n to be con
siderable, an d S. em pliasizes th e d esirab ility o f sta tin g w h etlier o r n o t th e necessary correction has been applied if th e above coeffs. are to be given.
— P . M. C. R .
♦ Denotes a paper deseribing th e results of original research.
f Denotes a first-class critical review.
U U
630 Metallurgical A bstracts
Yo l. 3*On the A verageV alue to be Given to th e T em perature Coefficient o£ the E le c tri
cal R esistance of A lum inium Conductors. O. S carp a (A llu m in io , 1935, 4, (3), 145-148).— V arious a tte m p ts w ere m ado b y tlie In te rn a tio n a l E lectro tech n ical Comm ission to fix th e valuc o f th is coeff. A ccu rate m easurem ents w ere m ade by S., a n d th e yalue suggested for alu m in iu m con d u cto rs in th e a s d ra w n s ta te is + 0-00405. Tho resistance o f a n alu m in iu m co n d u cto r can be o b tain ed th erefo re by tho e ą u a tio n : r, = 2-S40[l + 0-00405(i — 2 0 )]- |p , w here 2-840
20
is th e resistiv ity a t 20° C. o f d raw n alum inium ; /20 a n d S 20 being, respectiyely, tho len g th in cm ., a n d ayerage cross-sectional a re a in cm .2 a t 20° C. F o r alum inium conductors tr e a te d fo r 4 h rs. a t 250° C. th e suggested y a lu e is + 0-00410, a n d th e re s istiv ity can be o b tain ed , tlierefore, from th e e ą u a tio n : p, = 2-777[l + 0-0041(i — 20)]. T h e re sistiy ity o f annealed alu m in iu m a t 20° C. is 2-777. F ro m exp erim en ts carried o u t in th e sam o la b o ra to ry on I ta lia n alum inium , i t w as fo u n d t h a t th e averagc speeifie w eight o f alum inium conductors in th e annealed s ta te is g re a te r th a n t h a t fo r th e n o n -tre a te d m etal.
T h e av erag e speeifie w eight a t 20° C. o f n o n -tre a te d d raw n alu m in iu m is 2-705, a n d fo r tlie sam e m a te ria ł tr e a te d 4 hrs. a t 250° C. is 2-709.— J . K .
♦Electrical and Optical Investigation of th e T ransform ation from Non-Metallic to Metallic A ntim ony. R . S u h rm an n an d W . B e rn d t (P h y sik a l. Z ., 1936, 37, (5), 140-149).—E x p e rim e n ts are described in w hich th e changes o f electrical resistan ce a n d op tical a b so rp tio n o f th in films o f an tim o n y w ere used to show th e tra n sfo rm a tio n from am orphous to m etallic a n tim o n y . T h e films, w hich w ere p rep ared b y condensation a t liąu id a ir te m p e ra tu re in a y aeu u m , liave high resistances a n d te m p e ra tu re coeff. o f resistance com pared w ith tho m e t a l ; a fte r h e a tin g to a te m p e ra tu re w hich depends on th e thickness an d is betw een 270° a n d 320° A ., th e y becom e n o rm al in resp ect o f b o th resistance a n d o p tical ab so rp tio n . Tho films w ere from 15 to 109 m p th ic k .—B . C.
*The Vapour Pressure of B arium . J . A. M. v a n L ie m p t (Hec. trav. chim ., 1936, 55, (6), 468-470).— [I n G erm an.] F o rm u ł aa are given for th e y ap o u r pressure a n d yelocity o f y ap o rizatio n o f b a riu m in vacuo. Values o b tain ed b y H a rtm a n n a n d Schneider fo r tho la te n t h e a t o f y ap o rizatio n , boiling point, a n d T ro u to n ’s const. are considered to be too h ig h .— E . J . G.
*The Influence of Oxygen, Carbon Dioxide, Nitrogen, and M ercury on the Photoelectric Effect of B ariu m and Potassium . A. V. A fanasieya a n d Y u. I.
L u n ’k o y a (Z h u rn a l Tehnicheskoy F iz ik i (J . Tech. P hysics), 1935, 5, 1 0 0 0 - 1006).— [I n R ussian.]— S. G.
fP roperties and Alloys of B eryllium . Louis L . S to tt (T ra n s. A m er. In st.
M in . M et. E ng., 1936, 122, 57-73).—See M et. A b s., th is vol., p. 440.— S. G.
*The M agnetic P roperties of B ism uth. D av id Shocnberg (Abstracts o f D issertations U niv. Cambridge, 1935-1936, 120-121).—T h e m agnetic su scep ti
b ility o f b ism u th w as m easured b y th e F a ra d a y m ethod. Abovo 50° K . th e m agnetization-field curve is lin e a r ; below th is te m p e ra tu re i t is m ore compli- cate d , as a lrcad y n o te d by do H aas a n d v a n A lphen. D etails o f b o th tho n o rm al a n d th e do H a a s -v a n A lphen effect, a n d also th e influenco o f sm ali a d d itio n s o f lead a n d tellu riu m h av e been in v estig ated . T ho tran sv erse m ag n eto strictio n o f single cry stals w as m easured, a n d th e resu lts, w ith K a p itz a ’s earlier lo n g itu d in al d a ta , give a com plete schem e o f m ag n eto strictio n m oduli. T he effect o f foreign ato m s a n d t h a t o f te m p e ra tu re c a n n o t be ex- p lain ed by change o f la ttic e dim ensions. I t is eoncluded t h a t th e tlieories of Jo n es a n d Peierls provide too sim ple a p ic tu re o f th e electronic s tru c tu re o f b ism u th .— A. G. D.
*The H all Effect in a Circular B ism uth P late. L. H o w ard P etersen (Proc.
In d ia n a Aead, S ci., 1935, 45, 214-215).—Y o lterra (Nuovo cimento, 1915, 9, 23) developed a Priticiple o f R eeiprocity for th e H all effect in a circular p late. A lim enti (N vovo cimcnto, 1915, 9, 109, a n d 1916,11, 217) e ste n d e d th e
1936
I .— Properties of Metals 631
principle. L e t th e c u rre n t c n te r a n d leave a circular p la tc a t th e m id-points of p erp en d icu lar r a d i i ; A lim enti found four p o in ts on th e plato w here th e p o te n tia l dillerence betw een th e p oints in all conibinations of 2’s is th e sam e w hen th e field is excited. P . failed to confirm A .’s results in th e ease o f a circular b ism u th p late. A special caso occurs w hen th e curren t-carry in g electrodes aro situ a te d on th e circuraference o f th e plate. T h is is V .’s so-called
“ th eo rem o f four v erticcs.’! T h is theorem is confirm ed by P .—J . S. G. T.
The N orm al Cathode P otential Drop a t the M elting P oint in B ism uth. H . K u rzk e (A n n . P h y sik , 1936, 25, 68S-696).—T h e dependenco o f cathode d rop on te m p e ra tu ro w as in v estig ated by a m easu rem en t of tlie y a ria tio n o f cathodo p o te n tia l a n d te m p e ra tu re sim ultaneously d u rin g cooling. I t is shów n t h a t th e cathodo d rop inereases by a b o u t 2 v. on solidification for b ism u th , w hile for tin a n d lead it deereases. T h e change in eleefcron em ission w ork is related to th e figures o b tain ed fo r th e cathode d ro p .—B. C.
*The V apour Pressure of Ceesium. J . A. M. v a n L iem p t (Rec. trav. chitn., 1936, 55, (3), 157-160).— [In G erm an.] A t 300°-1000° abs. th e v a p o u r pressuro o f caosium is given b y tlie expression :— log p (m m .) = — (3701/21) + 6-62, a n d th e ra to o f su b lim atio n a t 270°-300° abs. b y th e c x p re s sio n : log p ~ — (3813/T ) + 5-74 + £ log T .— A . R . P .
*Atomic W eight of Calcium in Old P otassium -R ich M inerals. W . W . S m ith a n d T . T a it (Proc. R oy. Soc. E dinbunjli, 1933-1934, 54, (1), 88-101).— Values o f 40-089 a n d 40-092 w ere fo u n d fo r calcium e x tra c te d from tw o different sources.—S. G.
*The Diffusion of W ate r Vapour th ro u g h Copper. J . H . de B oer a n d J . D . F a s t (Rec. trav. ćhim ., 1935, 54, (12), 970-974).— [I n G erm an.] A t 800° C. th e ra te o f diffusion o f w ater y a p o u r th ro u g h 1 cm. o f copper is 1-9 X 10~12 m o l./cm .-/seco n d /atm . com pared w ith a value o f 23 X 10~12 m ol./cm .2/se c o n d /a tm .ł for hydrogen. N itrogen does n o t diffuse th ro u g h copper u n d er th ese conditions. W a te r y a p o u r does n o t diffuse th ro u g h ch ro m iu m -iro n alloys, w hereas n itro g en diffuses a t tlie ra te o f > 6-9 x 10~12 m ol./cm .2/s e c o n d /a tm .ł.— A. R . P .
*The R eaction of A tom ie H ydrogen and M etallic Copper. F ran cis A. Mc- M ahon a n d P e te r L. R obinson (J. Chem. Soc., 1934, (Ju n e), 854-855).—A tom ie hydrogen passed a t th e ra te o f 0-5 litre /h r. ov er copper w hich has been oxidized a n d reduced, o r roughened, gives a black Cu1 h ydridc soluble in 7 0% hydro- chloric acid in abscnce o f air.— S. G.
*Effect of Tim e on Tensile Properties of H ard-D raw n Copper W ire. A lb e rt J . P hillips an d A. A. S m ith , J r . (Proc. A m er. Soc. Test. M a t., 1936, 36, (I I), 2 6 3 - 27 3 ; discussion, 274—275).—Tho o b ject o f th is p a p e r is to show th e effect o f tim e on th e flow o f h a rd -d ra w n copper w ire u n d e r su stain ed loads. A n a c c u r
a te d e te rm in a tio n w as also m ade o f th e m odulus o f elasticity for b o th so ft an d h ard -d raw n copper w ires. T e st w ires wero fasten ed by sw ivel clam ps a t th e top, th re a d e d th ro u g h brass tu b in g a n d d ead w eights suspended a t tlie b o tto m by m eans o f su itab le clam ps. D eterm in atio n o f s tra in w as m ade w ith a p o rtab le m icroscope, m easuring th e distance betw een a knife edge a t th e b o tto m o f th e brass tu b in g a n d a n o th e r knife edge on a sm ali sleeve th re a d e d ov er tho wire. T he gaugc-lcngth was 60 in. a n d th e accuracy was ± 0-000004 in. p er in.
F ro m th e d a ta o b tain ed i t is concluded t h a t : (1) h a rd -d ra w n copper w ire will creep a t room te m p e ra tu re fo r m an y d ays even u n d er loads o f only 5 0 % o f th e tensile s t r e n g th ; (2) th e creep ch aracteristics o f different copper w ires aro sim ilar for a given percentage o f th e ir respectivc tensile stre n g th s ; (3) creep ch aracteristics are sim ilar fo r m te rm itte n tly a n d continuously lo ad ed w ires for tensile loads n o t exceeding 78% o f th e tensile s t r e n g th ; (4) th e m odulus o f elasticity o f eertain h ard -d raw n copper wires is 18,000,000 lb ./in .2 ± 400,000 lb ./in .2 ; (5) th e m odulus o f e lasticity o f ee rta in an n ealed copper w ires is 13,400,000 lb ./in .2 ± 5 0 0 ,0 0 0 lb ./in .2.— S. G.
632 Metallurgical Abstracts
Vo l. 3♦Principal E lastic Constants o! Single Crystals of Copper, Gold, and Lead.
E . Goens (P h y sik a l. Z ., 1936, 37, (9), 321-326).— A n acco u n t is given of m easurem ents o f th e prin cip al elastic co n stan ts o f copper, gold, a n d lead, using a preyiously deseribed dy n am ical m ethod. T he yalues o f th e co n stan ts aro given in d etail.— B. C.
♦Resistom etrical M ethod fo r D eterm ination of the E lectrotherm ic H om o- geneous Effect an d Gas ło n Effect [Copper ; Platinum ]. C. B enedicks, C. W.
B orgm ann, a n d P . Sedcrholm (A rkiv M at. A stron. F y sik , 1935, [A], 25, (9), 1-2S).— [I n E nglish.] A resistom etric m eth o d is in tro d u ced fo r th e d eterm in atio n o f th e electro th erm ic hom ogeneous effect in m etal wires.
T he m eth o d h as been used on w ires cxposcd to a gas atm osphere o f definite low pressure. I t is based on th e use o f a W h eatsto n e bridge, th e indications of w hich are d e p e n d e n t on tho d ireetion o f th e cu rren t. C opper gavo very reg u lar resu lts, o f correct sign, a t a b o u t 26° C .; a v a ria tio n o f pressure b e tw een 10~5 a n d 10-1 w as found to e x e rt a ra tlie r w eak influence on th e co n stan t o f th e effect. T his proyes th e . m eth o d to be reliablc. I n p la tin u m certain irregularities w ere observed w hich d epend on th e pressure o f th e gas surround- ing th e te s t w ire. I t is necessary to distinguish betw een (a) th e electrotherm ic hom ogeneous effect o f gas-free p la tin u m , being negative (“ m etal e ff e c t” ), a n d (b) a n electrotherm ic hom ogeneous effect depending on gas ions, causing a positive effect (“ gas e ff e c t” ). I n copper th e electrotherm ic hom ogeneous effect was likewisc found to som e e x te n t to bo d e p e n d e n t on th e gas pressure.
— S. G.
♦P aram agnetism of Metallie G adolinium Above Its Curie P oint. F elix T ro m b e (Com.pt. rend., 1935, 201, 652-653).— T h e specific su seep tib ility , y , o f gadolinium w as d e te rm in e d from 16° to 360° C. Tho p a ram ag n etic a n d ferrom agnetic Curio p o in ts aro a t 29-5° a n d 16° C., respectively.— S. G.
♦On the E lectrical R esistance of Gold a t Low T em peratures in Transverse M agnetic Fields.— I., II. E . J u s ti a n d H . Scheffcrs (P hysikal. Z ., 1936, 37, (10), 3 8 3 -3 8 4 ; (13), 475-481). (I.— ) I n spito o f th e cubic stru c tu re o f gold, tho o rie n ta tio n o f th e cry sta l axis to th e applied m agnetic fleld h as a considerable influence on tho resistance. Curyes are given show ing th is a n g u lar dependenco o f th e ra tio o f th e resistanco w ith a n d w ith o u t a m agnetic field (21-7 kilogauss) a t 20-38° a n d 14-0° abs. ( I I .— ) T he previously deseribed an iso tro p y o f gold crystals a t low te m p e ra tu re s w ith rcsp cct to electrical resistiv ity in transverso m agnetic fields is fu rth e r in v estig ated . I t is show n t h a t th e ra tio b y w hich th e resistance changes owing to a m ag n etic field depends on th e angle betw een
th e cry sta l axes a n d th e d ireetion o f th e field.— B . C.
♦The M agnetic Properties of L an th an u m , Cerium , and N eodymium . E.
T rom be (C om pt. rend., 1934, 198, 1591-1593).—T h e m etals co n tain ed n o t m ore th a n 0-05% Silicon a n d 0-02% ir o n ; th e y wero te s te d a t 16° C. in d ifferent fields. A t 3000 gauss th e yalues found fo r th e m a g n etic s u s e e p tib ility X X 10° w ere : la n th a n u m 1-21, cerium 17-94, neodym ium 39-48. Curves of y a ria tio n o f 1 /y_ w ith te m p e ra tu re show t h a t th e re is a slig h t docreaso o f th e su seep tib ility o f la n th a n u m a n d cerium w ith stro n g er fields, b u t t h a t of neodym ium is p ractically c o n sta n t. T h ere are tw o s ta te s o f cerium betw een 100° a n d 200° K . F o r lan th an u m a n d cerium th e re aro slig h t discontinuities a t 110° a n d 109° K ., respectively.— S. G.
♦Some Creep Tests on Lead and Lead Alloys. A lb e rt J . P hillips (Proc. A m er.
Soc. Test. M a t., 1936, 36, (I I), 1 7 0 -1 8 2 ; discussion, 183-193).— C reep te s t d a ta on lead a n d load alloys from te s ts o f 3 y e a rs’ d u ra tio n are p resen ted to show t h a t i t is unsafe to ex tra p o la to ereop ra te s calcu lated from sh o rt-tim c te s ts. M any alloying elem ents w hich inerease th e tensile s tre n g th o f lead decrease th e resistance to creep u n d e r low loads. C opper a d d ed to lead im proves th e creep resistance yery m arkedly. A n tim o n y decreases th e creep resistance ex cep t in th e age-hardened condition w here th e elongation u n d er
1936
I . — Properties o f Metals 633
fairly hig h tensile loads is p raetically nil. Such a m etal will fra c tu re , how eyer, w ith o u t flow u n d er su stain cd loads, m aking i t difficult, if n o t im possible, to calculate a safe w orking stress. T in likewise decreases th e crccp resistance of lead, b u t in th e h e a t-tre a te d condition tho alloy shows cxcellent crecp re s ist
ance w ith o u t serious loss in d u ctility . T ellurium a d d ed to lead decreases its creep resistance u n d e r Iow loads in b o th th e h ard -ro lled a n d th e annealed conditions.— S. G.
The Effect of Prolonged Tension on Lead and Its Alloys. H . S him ba (D en ki G akkwai Zasshi (./. In s t. Elect. E ng. Ja p a n ), 1930, 56, (5), 593-594).— [In Ja p a n e se .]—S. G.
*R elation between Field S trength and M agnetic Induction for Supercon- ducting Lead. J . N . R ja b in in a n d L. W . Schubnikow (P h ysika l. Z. Souyjet- u n io n , 1934, 6, (6), 5 5 7 -5 6 8 ; S ci. A bs., 1935, [A], 38, 439).— [I n G erm an.]
Two difTerent m ethods o f m easuring tho m agnetic in d u c tio n o f supercon- d u cto rs for different fields a n d tem p eratu res are described in d etail. A t tho te m p e ra tu re o f 4-24° K . th e dependence o f th e m agnetic in d u ctio n o f super- conductors on th e field w as in y estig ated , a n d a n a b r u p t inerease in th e in d u ctio n from B = 0 to B = I I w as fo u n d in generał a t th e tra n sitio n fro m th e supereonducting sta te . I n th o reverse process thero is also an a b ru p t change o f in d u ctio n for th e sam e fields. T h e process is n o t reversible, b u t is aecom panied b y m ark ed hysteresis.-—S. G.
*Methods for O btaining M agnesium Single Crystals from a Melt. M. D.
M ochaloy (Z h u m a l 'Tehnicheskoy F iz ik i (J. Tech. P hysics), 1936, 6, (4), 6 0 5 - 607).— [In R ussian.] A fuli descrip tio n is given o f th e m ethod o f pro d u ctio n o f m agnesium single cry stals (5 X 7 X 150 m m .) in a n iro n m ould plaeed h orizontally in th o furnace.— N . A.
*Constants of Elasticity, E lectrical R esistance, and T herm al E xpansion of M agnesium Crystals. E . Goens a n d E . Sclim id (P hysikal. Z ., 1936, 37, (11), 385-391).— B y m easurem ents on single-crystal rods o f m agnesium o f different crystallographic o rien tatio n s, th e a u th o rs d eterm ined th e prin cip al co n stan ts o f e lasticity a n d th e principal yalues o f th e specific resistance a t room tem p e ra tu re , th e re la tiy e electrical. resistan ce y alu es th e regiou + 100° to — 269° C., a n d th e prin cip al yalues o f th e th erm al expansion in th o ran g ę + 200° to — 253° C. Tho experim ental resu lts are discussed in com parison w ith th e corresponding yalues for zinc an d cadm ium .— P . W . R .
*Investigations on the N itriding of M agnesium and A lum inium . P . L affitte, E . E lcliard u s, a n d P . G ran d ad am (Rev. In d u st. minerale, 1936, (375), 8 61- 867).— T he te m p e ra tu re o f m cip ien t n itrid in g o f m agnesium b y n itro g en is show n to dep en d on preyious exposure to a ir in ad d itio n to th e u sual co n d itions o f pressure, r a te o f heating, &c. T he n itrid in g curve o b tain ed w hen am m onia w as used show ed a b reak a t 275° C., corresponding w ith a n an o m aly in tho te m p e ra tu re -re sis tiy ity curve o f m agnesium , a n d i t is suggested t h a t a n allotropic tra n sfo rm a tio n o f th e m etal m ay occur. A sim ilar b re a k in th e case o f alum inium is a ttrib u te d to im purities. N itrid in g -sp e e d curves a t d ifferent te m p e ra tu re s a re given fo r b o th m etals. T he n itrid in g te m p e ra tu re rangę fo r alum inium in am m onia is re s tric tc d b y th e dissociation o f th e p ro d u ct, w hich begins a t 265° C.— P . M. C. R .
Theory of Constant Param agnetism . Its A pplication to M anganese. L ouis N ćel (Com pt. rend., 1936, 203, (4), 304-306).—Cf. M et. A bs., th is vol., p. 201.
E x te n d e d generalizations d eriv ed from N .’s p reyious d em o n stratio n s o f su scep tib ility in d ep en d en t, a t Iow tem p eratu res, o f te m p e ra tu re . E x cellen t agreem en t is o b tain ed in th e case o f m anganese betw een th e o re tic a l a n d ex p erim en tal results.— E . J . G.
*Optical E xam ination of T hin Film s. I.— Optical Constants of M ercury.
L eif T ro n sta d a n d C. G. P . F eachem (Proc. Roy. Soc., 1934, [A], 145, 115-
634 Metallurgical Abstracts
Yo l. 3126).—T h e values o f th e op tical co n stan ts o f m ercury w ere m easured for Xk 4350, 5460, a n d 5780 A . ; th e y aro discussed in relatio n to previously pub lish ed values for w ave-lengths in th e visible region o f th e spectrum .
— S. O.
*The Electrical Conductivity o£ T hin Metal Film s, P articu larly oi Molybdenum Film s. J . H . de B oer a n d H . H . K ra a k (Rec. trav. chim ., 1936, 55, (9/10), 9 4 1 -9 5 3 ; a n d Laboratoria N .V . P h ilip s' Gloeilamp. Eindhoven, Separaat 1142,1936).— [In G erm an.] A n in v estig atio n o f th e co n d u ctiv ity o f sp u tto re d m olybdenum films as d ep en d en t on film thickness, an d w ith tlie glass basis surface a t different tem p eratu res, b o th d u rin g sp u tto rin g a n d d u rin g m easure- m e n t o f co n d u ctiv ity . A t all te m p e ra tu re s below th o m ax im u m to w hich tho film lias been su b jected , y a ria tio n s w ith te m p e ra tu ro aro p ractically rever- s ib lo ; abovo tho m ax im u m , how ever, th e c o n d u c tm ty increases irreversibly.
T h e th e o ry evolved rescm bles t h a t o f W ilson fo r sem i-conductors.— E . J . G.
*The E vaporation o£ Niekel in a V acuum . George B ryce (•/. Chem. Soc., 1936, (O ct.), 1517-1518).— F ro m ex p erim en ts on tho ra te o f o y ap o ratio n o f niekel atom s from a filam ent h e a te d a t 1318°-1602° abs. in a high vacuum (10-5 m m . o f m ercury) th e energy o f v ap o rizatio n o f niekel ato m s is deduccd to bc 85 kg.-cal. I f c is th e condensation coeff. o f niekel ato m s on a niekel surface a t T ° abs. a n d p is tho v a p o u r pressure o f niekel in m m . o f m ercu ry , th e n it can be show n t h a t log10 (cp) = 9-148 — 2-00 X 10'1/ T . —A. R . P .
♦The R ate of A dsorption of E thylene by Silica and Niekel. E . W . R . Steacie a n d H . V. S tovel (J. Chem. P hysics, 1934, 2, (9), 581-584).—T he ad so rp tio n o f ethylene b y reduced niekel w as stu d ie d from — 80° to 150° C.
D efinite slow effects a n d te m p e ra tu ro h ysteresis w ere observed. Since diffusion in to th e cry sta l la ttic e (“ s o lu b ility ” ) is oxtrem ely unlikely in th is case, m ore definite conclusions can be reached th a n h av e beon possible in previous investigations.— S. G.
*The Modulus of Torsion of M agnetized Niekel a t H igh T em peratures.
W . M óbius (P h ysiką l. Z ., 1934, 35, 8 0 6 -8 1 1 ; S ci. A bs., 1934, [A], 37, 1245).—
A co n tin u atio n o f w ork described in an earlier p ap er (M et. Abs. (J . In st. M etals), 1932, 50, 419). G reater field stre n g th s w ere em ployed an d m ore ac c u ra te te m p e ra tu re m easurem ents m ade, p a rtic u la rly in th e region o f th e C urie p o in t.— S. G.
*The M agnetic B ehaviour of Niekel a t T em peratures up to the Curie P oint.
W . S chnabl (A n n . P h ysik, 1936, 27, (2), 169-185).— T he depondencc o f m agnetic losses on freąu en ey is show n to be m ark ed betw een 0-50 and 500 H z, w hile betw een 50 a n d 500 H z am p litu d es dep en d stro n g ly on freąueney.
D ifferenees observed c a n n o t be a ttrib u te d to e d d y c u rre n t losses. A t higher te m p e ra tu re s th e freąu en ey effects deerease m ark cd lj', a n d p a rtia lly vanish.
— E . J . G.
t*R esistance, Spontaneous M agnetization, and Curie P oint of Niekel. W.
G erlach, H . B ittel, a n d S. Vekiyos (Sitzber. math.-naturu). A b t.b a y e r. A ka d . JFjss. M unchen, 1936, 8 1 -1 3 6 ; C. A bs., 1936, 30, 7401).—Tho resu lts o f m an y invcstigations on th o m agnetic a n d clectrical p ro p erties o f various specim ens o f niekel a re review ed, a n d anom alies in th e resistance are corrclated w ith changes in m agnetic properties. T h e p ap er is d m d e d in to 6 sections. (I.— ) T he re s ista n c e -te m p e ra tu re curves o f sam ples o f niekel o f v ary in g p u rity a re considered, a n d i t is show n t h a t by th e ap p licatio n o f M atthiessen’s ad d itio n rule th ese can all be red u ced to th o r - T curve fo r p u re s t niclccl (r, — R J R 0).
(I I.— ) D escribes in d e ta il new experim ents o f th e hig h est precision by B. an d V . on th e resistance o f niekel o f vario u s p u ritie s in th e rangę — 200° to + 600° C. (cf. M et. A bs., th is vol., p. 194). These resu lts confirm th e v a lid ity o f th e deductions o f Section I . ( I I I .— ) T he generał v a lid ity o f th e quan- tita tiv e interdependence o f tlie resistancc anom aly a n d tho sąu aro o f th e spontaneous m ag n etizatio n is show n, as well as t h a t th e p ro p o rtio n ality
1936
I . — Properties of Metals 635
const. is in d ep en d e n t o f tlie p u rity . (IV .— ) A diseussion is given o f a n in te r- p re ta tio n o f th e resistance anom aly proposed by B orelius (A n n . P h ysik, 1931, 8,261), whoso “ reduced resistance ” is co n trad icted by th e exp erim en tal d a ta . (V.— ) C onsideration o f th e resistance anom aly d em o n strates t h a t an in n er spontaneous m ag n etizatio n can bo d e te c te d far abovo th e te m p e ra tu re h ith e rto ta k e n as th e C urie p o in t. (V I.— ) E x p e rim e n ta l d a ta collected in th is seetion dem o n strato t h a t nickel g rad u ally loses its spontaneous m ag n etizatio n , an d w ith it also th e possibility o f ferrom agnetic m ag n etizatio n , first fa r above tlie previously assum ed Curie p o in t.—S. G.
*Tem perature V ariation o£ the S tructural D em agnetizing F acto r in Nickel and Cobalt. T heodore K a h a n (Compt. rand., 1934, 199, 349-351).— S. G.
^Ferrom agnetic Curie Points for Electrodeposited Nickel Film s. S. Procopiu a n d T. F arcas (Compt. rend., 1934, 198, 1983-1985).— See M at. A b s., th is vol., p. 194.— S. G.
*The B ehaviour of H ydrogen Dissolved in Palladium . K . F . H erzfeld a n d M aria G oppert-M ayer (Z. physikal. Chem., 1934, [B], 26, (3), 203-208).— S. G.
The In terp retatio n of th e D issociation Pressures of th e P alladium -H ydrogen System. M ax H . H ey (./. Chem. Soc., 1935, (Scpt.), 1254-1258).—Cf. H oy, M et. A bs., th is vol., p. 493. An e ą u a tio n dcvelopećl from sim ple kinetic th eo ry is show n to give a reasonably satisfacto ry acco u n t o f th e dissociation pressures o f th e p a llad iu m -h y d ro g en system , on th e assum ption t h a t th e re is only one phase p re s e n t th ro u g h o u t. T he lim iting com position o f tho system is P d H , w hich possibly has a sodium chloride ty p e stru c tu re . T he e q u atio n is p ro b ab ly a first ap p ro x im atio n to th e tr u th .— S. G.
*The D ependence of the Modulus of E lasticity, E lastic Lim it, an d U ltim ate Strength of P alladium on the H ydrogen Content. F . K ru g e r a n d H . J u n g n itz (Z. tech. P h y sik , 1936, 17, (9), 302-306).—T he m odulus o f elasticity , elastic lim it, a n d u ltim a te stre n g th o f a p allad iu m w ire are show n first to underg o a sm ali in itial inerease a n d th e n to decrease alm o st in p ro p o rtio n to th e gas co n ten t, u p to th o lim it o f sa tu ra tio n . T h e inerease coincides w ith ab so rp tio n in th e ato m ie form , th e su b scąu en t decrease w ith th e e n tr y o f m olecular hydrogen.— E . J . G.
Expansion Pressures of M etallic Hydrogen and D euterium . A. R . U bbc- lolide (N aturę, 1936, 138, (3498), 845).—Differerices in th e expansion o f th e spacc-lattice o f p allad iu m w hen alloyed w ith m etallic hyd ro g en an d d eu te riu m are ad d u ced as evidenco t h a t tho h ydrogen in c e rta in m etallic h y d rid es exists in th e m etallic s ta te .— P . M. C. R .
*Electronic Specific H eat in Palladium . G. L. P ic k a rd (N aturę, 1936, 138, (3481), 123).—T he specific h e a t o f palladium w as m easured betw een 2-5° an d 22° K ., an d th e resu lts are considercd in term s o f th o electronic th e o ry o f M o tt.
An expression is given fo r th e specific h e a t in th e rangę n am ed .— B . C.
tM etals of the P latin u m Group. Ores, Recovery and Refining, F abrication and Uses, an d Properties. R . H . A tkinson a n d A. R . R a p e r (./. In st. M etals, 1936, 59, 1 7 9-206; diseussion, 207-210).— A n a tte m p t is m ade to p resen t u p -to -d a te m etallurgical inform ation a b o u t th e 6 m etals o f th e p la tin u m group.
A fter a b rie f description o f tho discovery o f th e m etals a n d a n acco u n t o f th e ores, p a rtic u la r a tte n tio n is d ev o ted to tho recovery a n d refining o f tho m etals p roduced from th e C anadian nickel in d u stry . T h is is followed b y a fuli description o f th e m ethods o f fab ricatio n o f th e m etals a n d th e ir alloys. I t is show n t h a t th e tw o ductilo m etals o f th e group, p la tin u m an d p allad iu m , are read ily w orked, while rhodium a n d iridium are w orked w ith m uch g re a te r difficulty. T he tw o m etals osm ium an d ru th en iu m , belonging to th e hexagonal sy stem , h a v e n o t u p to th e p resen t been thoro u g h ly in yestigated. F in ally , a n acc o u n t is given o f th e p ro p erties o f th e m etals a n d th e ir uses.— R . H . A.
*The Adsorption of Oxygen on P latinum , Iro n Oxide, and Chrom ium Oxide.
B ern h ard N eu m an n a n d E ric h Goebel (Z. Elektrochem., 1934, 40, 754r-764).—
636 Metallurgical Abstracts
Yo l. 3T h e ad so rp tio n o f o sy g en on p la tin u m w as m easured over th o rango 20° to 400° C. T lie iso b ar for oxygen on p la tin u m inereased w ith inereasing te m p era tu ro betw een 20° a n d 300° C. a n d deereased a t higher tem p eratu res. A com parison is m ade o f tlie m easured values w ith th e eq u atio n s o f F reu n d lich a n d o f L a n g m u ir; th e agreem en t for b o tli e ąu atio n s is good for p la tin u m a n d iron o x id e ; fo r chrom ium oxide th o L an g m u ir e ą u a tio n gives tlie b e tte r ag reem ent.— S. G.
*The K inetics o! the A dsorption of H ydrogen and D euterium by Platinum . E d w a rd B. M axtcd an d C harles H . Moon (J. Chem. Soc., 1936, (O ct.), 1542- 1546).—T he early stages o f ad so rp tio n o f hydrogen a n d d e u teriu m b y p latin u m closely follow a n e ą u a tio n o f tho ty p e log a/(a — x ) — kt", in w hich a is th e sa tu ra tio n eap acity . F o r hy d ro g en k = 0-0955 a n d n = 0-326 a n d n k (which is a tr u c m casure o f th e ra te o f adso rp tio n ) is 0-0311 a t 18° C. T h e ra tio of th e values fo r n k for hydrogen a n d d eu teriu m is 1-4-1-5.— A. R . P .
*The Catalytic P roperties and Structure of Metal Film s. H .— The E lectrical Condition o£ P latin u m Film s. G. I . F in c h a n d A. W . I k in (Proc. R oy. Soc.,
1934, [A], 145, 551-563).—T he surface p o te n tia ls a n d ra te s o f charging-up of s p u tte re d p la tin u m films in c o n tac t w ith electrolytic gas a t room te m p e ra tu re w ere d eterm in ed , a n d th e film stru c tu re s exam ined by electron diffraction.
E lectrically activ e films w ere also cata ly tically activ e, w h ilst electrically n e iitra l films w ere in e rt as cata ly sts. T h e ra te s a t w hich activ e films pro- m oted th e u n io n o f oxygen a n d h ydrogen w ere d irectly p ro p o rtio n al to th e ir ra te s o f charging-up. W ith th e m ore aetiv e films, th e cry stals were array ed a t random , w hereas w ith in activ c films a considerable p ro p o rtio n o f crystals possessed a com m on d irectio n o f o rien tatio n . T h e diffuse back g ro u n d in electron d iflrac tio n p a tte rn s o b tain ed from ac tiv e film s inereased in in te n sity w ith inereasing a c tiv ity . H eatin g ra p id ly d estroyed tho la te n t a c tiv ity o f a film, a n d w hen sufficiently prolonged also broke dow n th o cry sta l stru c tu re . F ro m tliese facts in conjunction w ith those se t fo rth in P a r t I (M et. Abs. (J.
In s t. M etals), 1933, 53, 611) it is concluded th a t , u n d er th e conditions o f th e e x p e rim e n ts : (1) c a ta ly tic actio n w as d eterm in ed b y a p rio r in teractio n betw een th e surface a n d one o r b o th c o n stitu en ts o f th e com bining m ix tu re, w h ereby th e e a ta ly st becam e electrically e h a rg e d ; (2) a c tiv ity w as n o t d eterm in ed b y e ith e r cry stal size o r o r ie n ta tio n ; (3) c a ta ly tic a c tiv ity m ay h ave been cen trcd aro u n d atom s o f p la tin u m n o t form ing p a r t o f a n y ordered a rr a y o r s tru c tu re .— S. G.
*Variations of the R esistance of a [P latinum ] M etallic Conductor of Smali V olume. J . B e rn a m o n t (Compt. rend., 1934,198, 2144—2146).— M easurem ents w ere m ade o f th e v ariatio n s o f resistance o f a p latin u m w ire o f 1 ij. d iam eter to w ard s c u rre n ts o f freąuencies u p to 8 kc.— S. G.
*Conductivity of Tliin M etallic Film s [G o ld ; P latinum ] in a n E lectrostatic Field. E . P cru cca (A tli R . Accad. Sci. Torino, 1934, 69, (1), D isp. 2, 166-170 ; Sci. A bs., 1934, [A], 37, 717).—M etallic films o f gold a n d o f p la tin u m deposited on ą u a rtz , haying a resistance com prised betw een ~ 1012 an d ~ 1010 ohm s, h av e show n a co n d u ctiv ity stro n g ly v ariab le in a reversiblc m an n er w ith th e e lec tro static charge. T he effect consists alw ays in a n increase o f th e con- d u c tiv ity b y th e a ctio n o f th e e x tern al field, w h atev er m ay be th e sign o f th e charge. Inereases o f c o n d u c tm ty u p to 4 0 % h av e been observed.— S. G.
*P aram agnetic Susceptibility of Colloidal Pow der of P latinum . N oboro T a k a to ri (Sci. R ep. Tóhokii Im p . U niv., 1936, [i],' 25, (3), 489-503).— [In E nglish.] See a b s tra c t from jo u rn al published in ja p a n e se , M et. A bs., th is vol., p. 239.—S. G.
*Tke Optical Constants of P otassium . H e rb e rt E . Iv e s a n d H . B . B riggs (./. Opt. Soc. A m er., 1936, 26, (6), 238-246).—T h e m etliod o f V oigt w as used fo r d eterm in atio n o f th e op tical co n stan ts for th e u ltra -v io le t region. P o ta s s
iu m w as condensed on a ą u a rtz p la te an d covered w ith glass, th e m etal being
1936
I . — Properties of Metals 637
su b se ą u e n tly m elted to give com plete co n tac t. D a ta aro givcn show ing y ariatio n in rcflecting pow er o f th e m etal over th e rango 250 0 -6 0 0 0 A. an d cal- cu lated transm ission fo r thicknesses o f m etal o f 1-25 to 7-5 X 10-5 cm . T he transm ission falls ra p id ly above a w avc-lcngth o f 3000 A.— R . G.
♦Atomie W ork-F unction of T ungsten for Potassium . R . C. E v a n s (Proc.
Roy. Soc., 1934, [A], 145, 135-144).— S. G.
M agnetochem istry of R henium . N icolas P erak is a n d L ćan d re C apatos (J. P hys. R a d iu m , 1935, 6, (11), 462-468).— Cf. M et. A bs., th is vol., p. 239.
— S. G.
♦Transparency of Sodium and P otassium Film s in the Schum ann R egion.
W . H . W atson a n d D. G. H u rs t (N aturę, 1936, 138, (3481), 124).—Tho tran s- p aren cy o f th in films o f sodium an d potassium in th e fa r u ltra -v io le t was d eterm ined. I t is p o in ted o u t t h a t tho resu lts confliet w ith th e th eo ry o f th e optical properties o f m etals.—B . C.
Calculated and E xperim ental P hotoelectric E m ission from T hin Film s of Potassium . H e rb e rt E . Iv es a n d H . B . B riggs (J. Opt. Soc. A m er., 1936, 26, (6), 247-250).— E x p e rim e n ta l d a ta su p p o rte d th e th e o ry o f Iv e s respccting photoelectric em ission from th in films. I n vicw o f th is, it is concluded t h a t th e oecurrenco o f sp e c tra l m ax im a o f em ission w ith b u lk alkali m etals m u s t be regarded as a c tu a lly th in film p henom ena.— R . G.
♦The Catalytic and Electrical Properties of Metallie Surfaces. I.— A Silver Surface Catalyzing th e Combustion of Carbonic Oxide. B . W . B rad fo rd (J.
Chem. Soc., 1934, (Sept.), 1276-1283).— S. G.
♦Changes of Resistance of M etallie Film s D ue to Charging [Silyer, Gold, Copper, B ism uth]. A lexander D eu b n er (A n n . P h ysik, 1934, 20, 449-462).
♦A New Interference Phenom enon in the Passage of F ast E lectrons T hrough Crystals [Silver]. F . K irc h n e r a n d II. Lassen (A n n . P h ysik, 1935, 24, 113-123).—A new ty p e o f cry stal la ttic e interference has been fo u n d in th e stu d y o f th in silyer layers. T he in terference p o in ts form a cross. T h is phenom enon is aseribed to th e irra d ia tio n o f m any sm ali silyer crystals, w hich are sp read on th e surface, orien ted cx actly parallel.— S. G.
♦Dispersion of the Phase Change for Reflection of Light from Thin M etallie Layers [Silver, Gold, P latinum ]. J . B a u e r (A n n . P h ysik, 1934, 20, (5), 4 8 1 - 501).—T h in layers o f silver, gold, a n d p la tin u m w ere produced p a rtly by cathodic sp u tte rin g an d p a rtly by yapo rizatio n in high vacuo, a n d th e m easure
m en ts in th o yisible region w ere m ade by m odifying F a b ry an d B uisson’s m ethod. T h ere is a close connection betw een th e p hase change a n d th e ab so rp tio n coeff. T he tw o m odifications o f silyer fo u n d b y F a b ry a n d B uisson were show n to be identical w ith those o f R itschl. W ith non-hom ogencous layers th e phase change is n o t th e sam e a t different points. A th eo retical stu d y shows t h a t tho dependence o f th e phase change on w ave-length is duo to reflection w ith in th e m etallie layers a t th e b o u n d ary surface. T hus, w hile form erly th o interference phenom ena w ith th e F a b r y - P c r o t g ra tin g were considered as a tw o-surface problem (A iry form uła) th e y are conceived here as a four-surfaee problem . I t provides fo r th e different m etals th e relatio n o f ph ase change a n d w ave-length found ex p erim en tally .— S. G.
♦The E nergy D istribution of Photoelectrons from Sodium. A. G. H ill a n d L . A. D uB ridge (P hys. R ev., 1936, [ii], 49, (11), 877).— A b stra c t o f a p ap er read before th e A m erican P hysical Society.—-S. G.
♦The Creep of Tin and Tin Alloys.—I. D. H an so n a n d E . J . S andford (./.
In st. M etals, 1936, 59, 159-1 7 6 ; discussion, 176-178).— D escribes results o f creep tests o f long d u ra tio n on tin a n d som e o f its alloys in th e rolled con- dition. Silyer u p to 3 '5 % g reatly im provcs th e creep-resistance o f tin . B is m u th -tin alloys a re m ore re s ista n t to flow th a n pu re tin a t stresses above a b o u t 300 lb ./in .2, b u t a t low er stresses th e y are inferior to pu re tin . A ntim ony im proyes th e creep properties o f tin : th e alloy containing 8-5% a n tim o n y
638 Metallurgical A bstracłs
Yo l. 3w itlistan d s a stress 3 tim es th a t o f p u re tin for a n eq u al d u ra tio n . C ad m iu m - tin alloys are g reatly im proved by h e a t-tre a tm e n t a n d ofler considerablo resistance to creep. Tlie m echanism o f failure o f these alloys is discussed.
R esu lts are giyen o f te s ts on le a d - tin solders a n d on th e c a d m iu m -tin eu tectic alloy : these flow u n d e r stresses as Iow as 130-150 lb ./in .2. I t is show n th a t in m an y cases th e re is no relatio n sh ip betw een resistance to creep a n d u ltim ato tensile stre n g th .— D . H .
*A R elation betw een H eat of T ransition and T ransition P oint of E n an tio - tropie Modifications [Tinl. J . A. M. v a n L iem p t (Rec. Iran. chim ., 1935, 54, 9 3 4 -9 3 6 ; B rit. Chem. A b s., 1936, [A], 276).— [I n G erm an.] A n e ą u a tio n is dcrived connecting h e a t o f transm ission w ith te m p e ra tu re , a n d th e ato m ie freąuencies a n d densities o f th e m odifications a t th e tra n sitio n te m p e ra tu re . D ire c t confirm ation is lacking, owing to abscnce o f d a ta , b u t b y s u b s titu tin g th e ra tio o f th e a to m ie freąuencies by th o ra tio o f th e absolute te m p e ra tu re a t w hich th e form s h ave e ą u a l specific h eats, th e calcu lated tra n sitio n te m p e ra tu re s fo r tin a n d su lp h u r a re o f th e sam e order as th e exp erim en tal yalues.
— S. G.
♦The Adsorption of H ydrogen on T ungsten. W . F ra n k e n b u rg e r an d A.
H o d ler (N a tu n m ss., 1935, 23, (35), 609).—T h e phenom ena o f “ a c tiv a te d ad so rp tio n ” are stu d ie d for hydrogen on tu n g s te n ; th e y are show n to bo n o n -ex isten t i f b o th m a te ria ls aro ex trem ely pu re, an d it is suggested t h a t th e y depend on “ fractio n al self-purification ” o f tho m etallic surface in th o presence o f sm ali a m o u n ts o f oxygen a n d organie com pounds. A dsorption isobars fo r p u re tu n g ste n are repro d u ced , as are th e curves previously o b tain ed by T ay lo r.—P . M. C. R .
♦Adsorption of Nitrogen on Tungsten. J . K . R o b e rts (N a tu rę, 1936, 137, (3468), 659-660).— I t is show n t h a t th e ad so rp tio n o f sm ali ą u a n titie s of n itro g en on tu n g ste n tak es place rap id ly , p ro v id ed t h a t th e ą u a n tity o f n itrogen is less th a n sufficient to cover th e surface o f th e w ire.— B . C.
T ungsten-T horium Problem , n .—-The A nom alous A ctivation. E . Chalfin (Physikal. Z . Sow jetunion, 1934, 5, (6), 838-847).— [In G erm an.] Tho anom alies o f th e a c tiv a tio n o f th o ria te d tu n g ste n arc caused b y fluctuations o f th e d is trib u tio n o f th o riu m ato m s on th o surface o f th e tu n g sten . T he electron em ission from a th o ria te d tu n g ste n surface depends n o t only on th e n u m b er b u t also on th e d is trib u tio n o f th e th o riu m atom s on th e surface. Cal
cu latio n o f th e surface covered is possible only w hen th e a c tiy a tio n curve is n o rm a l; in th e a b n o rm al region larg er values th a n th e tr u e valuc o f th e surface covering aro o b tain ed .— S. G.
♦Picture of the [Electron] E m ission Process from T horiated T ungsten and Thoriated M olybdenum. E . B riiche a n d H . M ahl (Z. tech. P h ysik, 1935, 16, (12), 6 2 3-627; 1936, 17, (3), 8 1 -8 4 ; (8), 262-266).— I n th e first tw o p apers o f th is series th e electron m icroscope h as been ap p lied to o b ta in p ictu rcs o f d etails show n b y th e surface o f th o ria te d tu n g ste n d u rin g th e processes o f electron emission. P h en o m en a associated w ith th e processes o f h eatin g , red u ctio n , a c tiv a tio n , a n d d e-activ atio n are observed a n d discussed in con
siderable detail. T he th o riu m m etal is n o t uniform ly dispersed th ro u g h o u t th e superficial cry stal la ttic e o f th e su p p o rtin g tu n g ste n m etal b u t occurs a t a n u m b e r o f discrete pointa o f th e surface, a n d can m igratc over th e surface.
I n th e th ird p a p e r it is show n t h a t th e process a n d m echanism o f electron em ission are th e sam e from th o ria te d m olybdenum as from th o ria te d tu n g ste n .
— J . S. G. T.
♦The Properties of Metallic U ranium . H . A. M ayor (Abstracts D issertations Dr. P hil. U niv. Oxford, 1936, 8, 118-119).—T h e a to m ie h e a t o f u ran iu m , m easured betw een 30° a n d 60° ab s., is in ag reem en t w ith th eo ry . A t higher tem p eratu res, how eyer, th e m easured yalues inerease ab o v e th e th eo retical
1936
I . — Properties of Metals 639
value, a n d a p p e a r to continue to increase, reach in g th e value o f 6-7 cal. a t 00° C.— C. E . 11.
* Growth of Crystals of Zinc Containing Cadm ium by the C zochralski- Gomperz Method. H aro ld K . Schilling (P hysics, 1935, 6, (3), 111-116).— I n previous experim cnts i t was found im possible to d u p licate resu lts of H oyem an d T y n d all (Phys. R ev., 1929, 33, 81), w ho found a “ r a n g o ” for th e suc- cessful grow th o f single crystals o f zinc. M ost specim ens w ere “ optically m osaic.” I t is now show n th a t , by a d d in g cadm ium to zino o f highest p u rity , single crystals can be grow n, an d t h a t a “ rango ” is connccted w ith th e ir grow th. T h e rango is sim ilar to , b u t n o t id en tical w ith , t h a t o f H oyem a n d T yndall. M oreover, th e shape o f th e rangę is d ep en d en t on th e cadm ium c o n te n t a n d on th e speed o f g ro w th o f th e crystals. O ptical m osaics as well as th e changes o f H oyem a n d T y n d all aro fo u n d outsido th e rangę. In generał, o p tical m osaics are less fre ą u c n t th o higher th e cadm ium content.
C ertain surface m ark in g s a p p e a r on tlie crystals even for only 0-20% cadm ium ; these aro belicved to bo identical w ith m arkings previously described by R o sb au d a n d Schm id an d by S trau m an is, a n d p ro b ab ly in d ieate co n cen tratio n o f cadm ium along basal p lanes.— S. G.
*Creep and Twinning in Zinc Single Crystals. R ich ard F . Miller (T rans.
A m er. In s t. M in . M et. E ng., 1936, 122, 1 7 6-190; discussion, 190-191).— See M et. th is vol., p. 343.— S. G.
*“ Ju m p ” -Like D eform ation of Zinc Crystals. E . S. Jak o v lev a an d M. V.
J a k u to v ic h (Zlm rnal Tehnicheskoy F iz ik i (J. Tech. Physics), 1935, 5, (10), 1744-1759).— [I n R ussian.] A survcy is given o f lite ra tu rę on “ ju m p ” -liko d eform ation. A m icro-study w as carried o u t 011 zinc crystals o f th e d is tri
b u tio n o f d eform ation, corrcsponding to a series o f consccutive jum ps. Curves o f in d m d u a l a n d o f a series o f consccutive ju m p s du rin g extension o f zinc crystals w ere o b tain ed photographically. T he force diagram s o f soparato ju m p s w ere ob tain ed graphically. E e c o v e ry curves o f a stretelicd zinc cry stal are given. On th e basis o f th e experim ental m ateriał, a th e o ry of th e process o f “ ju m p ” -lilie d eform ation is evolved.—N . A.
*On the E nergy States of Valency Electrons in Some M etals. I.— The Crystal E nergy Levels of Valency Electrons in Zinc (1). M ituru S ató (Sci. Hep. TOhoku lm p . U niv., 1936, [i], H onda A nniv. Vol., 136-145).— [In E nglish.] See a b s tra c t from jo u rn al p rin te d in Jap an ese, M et. A bs., th is vol., p. 396.— S. G.
*The a-(3 T ransition in Zirconium in the Presence of Hydrogen. J . H . de B oer a n d J . D. F a s t (Hec. trav. chim ., 1936, 55, (5), 350-356).— [I n E nglish.]
H ydrogen dissolves in b o th form s o f zirconium an d w ith inereasing te m p e ra tu re th e solubility deereases, b u t a t th e tran sfo rm atio n p o in t th e re is a sudden increase in solubility, th e m etal absorbing tlie gas d u rin g th e tr a n s form ation a n d th e n g rad u ally losing i t again as th e te m p e ra tu re is inereased fu rth e r. T he change in solubility is ex actly reversible (sce also following a b stra c ts).—A. R . P .
*The ct-S T ransition w ith M echanically T reated and w ith U ntreated Zirconium . J . H . dc .Boer, P . Clausing, a n d J . D. F a s t (Rec. trav. chim ., 1936, 55, (6), 450-458).— [In E nglish.] Cf. a b stra c ts abovo a n d below. T he a -fł tran sfo rm atio n in p u re zirconium occurs a t 865° ± 10° C. O th er values recorded b y previous w orkers are show n to be due to ab so rp tio n o f gases from th e a ir d u rin g m echanical w orking a n d annealing. T he to ta l ra d ia tio n o f lig h t b y fi-zirconium is p ro p o rtio n al to T*'7.— A. R . P .
*The Influence of Oxygen and N itrogen on the a -fł T ransition of Z irconium . J . H . de B oer a n d J . D. F a s t (Rec. trav. chim ., 1936, 55, (6), 459-467).—
[I n E nglish.] Cf. preceding a b stra c ts. Z irconium can dissolve u p to 10 ato m ic-% o f oxygen o r n itro g en w ith corrcsponding w idening o f th e oc-(3 tra n sfo rm a tio n rangę, th e fully o x y g en -satu rated m etal show ing a rango o f from < 9 1 0 ° to > 1550° C. d u rin g w hich th e [i-phase w ith a low oxvgen
640 Metallurgical Abstracts
Yo l. 3c o n te n t is in e ą u ilib riu m w ith th e a-p h ase o f high oxygen co n ten t. Zirconium co n tain in g oxygen o r n itro g en sliows cohsiderable hysteresis effects in th e te m p e ra tu ro -e le c tric a l resistance curve, w hich a re a b se n t in th e case o f th e p u re m etal.—A. R . P .
On the Change of the R esistance of A lkali M etals in a M agnetic Field.
M. K o retz (P h ysika l. Z . Sow jetunion, 1934, 5, (6), 877-886).— [I n E nglish.]
See M et. A b s., 1934, 1, 93.—S. G.
The His of M etals. Epidem ie and Contagious. A ugusto H o llard [Buli, Soc.
ćTEncour., 1936, 135, (10 a n d 11), 593-608).— Season-eracking, season- crack in g in tin , “ tin p e st,” th e a tta c k o f lead b y H eller’s solution, fatigue in lead, a n d fissures in steel rails arc briefly described as exam ples o f “ diseases o f m etals.” [Note by A b stra cto r: T ho in te rc ry sta llin e a tta c k o f H cller’s solution on lead is n o t now considered to pro d u ce a n allo tro p ic change.]
— J . C. C.
R ecent R esearch in E lasticity. J . N . G oodier (J. A p p lied M echanics, 1936, 3, A 26-27).— A sh o rt review .— S. G.
F ractu res in M etals and B rittle M aterials. --- (N aturę, 1936, 138, (3481), 132-133).— R e p o rt o f Discussion a t th e R o y al Society. A n acco u n t is given o f a discussion on th e problem o f fractu re. T he discussion w as opened by II . J . Oough, w ho pointed o u t th e im portance o f w ork on single crystals, and th a t recen t w ork show ed t h a t a ty p e o f recrystallization occurs u n d er fatigue failure conditions. O. I . Taylor discussed th e m ath em atical th eo ry o f in tern al flaws, an d L . N . G. F ilon d e a lt w ith th e different ty p es o f fractu ro th a t occur in solids. E . N . da C. Andrade gave a n acco u n t o f evidence poin tin g to th e im portance o f surface cracks in in itiatin g failure. W . II . Hatfield discussed tho effect o f inclusions a n d grain-size on tho m echanical properties o f a m etal.
B . P . Ilaigh discussed tlie possibility o f slip depending on th e pro d u ctio n of am orphous m etal, a n d --- M a in suggested t h a t insufficient a tte n tio n had been p aid to speed an d te m p e ra tu re o f testin g . S ir Robert U adfield also discussed som e aspects o f th e cjuestion o f th e speed o f testin g .— B. C.
*R andom F ractu re of a B rittle Solid. C. C. L ienau (./. F ra n klin In s t., 1936, 221, (4), 485—194; (5), 6 7 3 -6 8 6 ; (6), 769-787).— B rittlen ess is considered as a n intensive p ro p e rty o f a solid w hich depends, am ong o th e r th ings, on te m p e ra tu re . T he eom m on conception o f b rittlen ess is m ade m ore precise by m easuring th e resistance to sh a tte rin g by u /3 k , w here u is th e u ltim a te sta tic ten sio n a n d k tho bu lk elastic m odulus. A sta tistic a lly hom ogeneous b rittle solid is considered to fail along surfaces w here th e average positive tension becomes u. T he average w ork o f th e b o u n d a ry forces p rio r to fractu ro is t h a t necessary to p roduce a hom ogeneous ten sio n u in th o solid. W hen fractu ro occurs, a s ta tio n a ry s ta te is a tta in e d in a tim o sh o rt com pared w ith th e pre- fra c tu re period. A m ath em atical th eo ry o f random fractu ro is developed, based on these conceptions, a n d em ploying ee rta in d istrib u tio n fu n etio n s d erived from Poisson’s law o f sm ali num bers. Surface friction a n d plastic deform ations aro supposed negligible. E x p e rim e n ta l resu lts o b tain ed in th e fra c tu re o f 1200 b rittle sp a g h e tti rods agfco w ith th eo retical a n tic ip a tio n s fairly satisfacto rily . T h e th e o ry is in acco rd w ith th e ex p erim en tal resu lts o f M artin [Trans. In s t. Chem. E n g ., 1926, 4, 42), G audin, a n d T e ra d a .— J . S. G. T.
*Strength of M etals in the Light of M odem Physics. H . J . G ough a n d W . A.
W ood (,/. Roy. Aeronaut. Soc., 1936, 40, (308), 5 8 6 -6 1 6 ; discussion, 6 1 6 -6 2 1 ; also M et. In d , [Lond,), 1936, 48, (19), 5 3 2 -5 3 6 ; a n d (sum m ary) Engineering, 1936,141, (3672), 590).— F aiiu res u n d e r s ta tic a n d fatig u e stressing are stu d ied w ith tho a id o f precise m eth o d s o f X -ra y diffraction. T he effects o f s ta tic tensile a n d torsional stressing, a n d also o f 3 ty p e s o f cyclic stressing, on specially p rep ared test-pieces o f m ild steel arc described. F ailu re u n d e r sta tic a n d fatigue stressing is assoeiated w ith changes in th o crystalline s tru c tu re w hich are identical. T hese are (1) dislocation o f th e originally perfect g rains
1936
I . — Properties of Metals 641
in to large com ponents th e o rien tatio n s o f w hich v a ry from th a t o f th e in te rn a l gram by a m o u n ts u p to 2 ° ; (2) th e form ation o f “ crystallites ” a b o u t 10-4 to 10-:‘ cm. in size whose o rien tatio n differs w idely from t h a t o f th e original g r a in s ; a n d (3) th e prcsence o f scvere in te rn a l stra in s in th e “ cry stallites.”
X -ra y diffraction m ethods distinguish elearly betw een th e effects o f app licatio n of safe a n d unsafe stresses. T ho p resen t position o f know ledge on tho inner stru c tu re o f m etals, effects o f cold-rolling a n d draw ing, s tre n g th a n d atom ie stru c tu re , a n d im perfcctions o f crystals is surveyed.—H . S.
R eport of [A.S.T.M.] R esearch Comm ittee on Fatigue of M etals. H . F . Moore (Proc. A m er. Soc. Test. M a t., 1936, 36, (I), 123-124).— R e p o rts on co- operatiye w o rk w ith C om m ittee E -4 on M etallography, an d on n o to w o rth y devclopm ents o f th e y ear in fatig u e te stin g .—S. G.
The P ractical Im portance of the D am ping Capacity of M etals, Especially Steels. O. F ó p p l. A ppendix : A Note on th e Term inology of D am ping and Fatigue. F . B acon (./. Iro n Steel In s t., 1936, 134, 3 9 3 -4 2 3 ; discussion, 424-455).— See M et. A b s., th is vol., p. 499.— S. G.
*The M eaning and the M easurem ent of H ardness. E . G. M ahin (Proc.
In d ia n a A cad. S ci., 1935, 45, 217-219).—A m etal, su b jected to p lastic d eform ation, becomes h a rd e r an d stro n g er, as m easured b y its resistance to fu rth e r deform ation u n d er stress. Is hardness, th e n , to be considered as a m easure o f resistance to a n y p e rm a n e n t deform ation, how ever sm ali, or as a m easure o f th e a b ility o f th e m etal finally to stop deform ation ? I f th e la tte r, th e n tho “ h ardness o f m etals, as m easured b y an}' existing m eth o d , is the hardness o f strain -h ard en ed m a te r ia ł; if th o form er, th e n thero is no sta n d a rd m eth o d o f d eterm ining hardness. B y absolide hardness is m e a n t tho m axim um u n it stress w hich a m etal w ill su p p o rt, applied th ro u g h a loaded p e n e tra to r, w ith o u t suffering a n y p e rm a n e n t deform ation. H arris (./. In s t. M etals, 1922, 28, 327) has a tte m p te d to determ ine such absolute h ardness b y ob scrv atio n o f th e sequenee o f values o f th e p e n e tra tio n o f a B rinell bali into a m etal w hich was annealed su b seąu en tly to each app licatio n o f th e load. Tw o objections are raised to th is proceduro. M. a tte m p ts to rem ove tho com plications o f th is m eth o d b y producing a “ B rinell ” im pression b y m echanical rem oval o f m etal r a th e r th a n by inducing p lastic flow. F o r th is purpose, a fte r perform ing a co nventional B rinell te s t, a series o f depressions is m ade b y a special drill u n til a d e p th o f drilling is fo u n d such t h a t th e B rinell bali, u n d er selected load, ju s t fails to w iden th e im pression. A bsolute hardness, so d eterm ined, is m uch low er th a n th e conventional hardness. I t is hoped t h a t tho w ork-hardening c ap acity o f m etals, &c., m ay bc exprcsscd in term s o f th e tw o h ardness n um bers.— J . S. G. T.
*The Surface T em perature of Sliding M etals, an d th e A rea and N aturę of Contact of th e Moving Surfaces. K e n n e th E d g a r W illiam R id ler (Abstracts o f D issertations U niv. Cambridge, 1935-1936, 110-111).— B y using th e c o n ta c t surfaco o f tw o different m etals as a th erm o ju n o tio n , th e te m p e ra tu re o f th e sliding m etals a t th e p o in t o f c o n ta c t can be m easured. T h is m a y excced 1000° C. Tho increase in te m p e ra tu ro is d ircctly p ro p o rtio n al to load, speed, a n d coeff. o f frictio n , a n d inversely p ro p o rtio n al to th e sąu aro ro o t o f tho th e rm a l co n d u ctiv ity . W ith m o st m etals th o te m p e ra tu ro increases to th e m elting p o in t. O ver 600° C. w as reach ed w ith lu b ric a te d surfaces. F ro m th e m easured te m p e ra tu re , a n ap p ro x im a te “ ra d iu s o f c o n ta c t ” is calculated.
T h is is show n to be in d ep en d e n t o f tho load, geom etrical area, a n d surface finish. M easurem ents o f electrical resistance s u p p o rt tho view t h a t th e re a l a re a o f co n ta c t is in d ep en d e n t o f speed, load, an d geom etrical are a .— A. G. D .
The W ear of M etals under Sliding Friction. - — - (M etallurgist (S u p p t. to Engineer), 1936, 10, 164-165).— A b rief review o f som e recen t p ap ers b y H . M eyer, B. K elil, an d E . Siebel (see M et. A b s., th is yo l., p . 249), M. v on Schw arz, a n d R . K och (see M et. A bs., th is y o l., p . 122).— R . G.
