METALLURGY AND THE FOUNDRY

Mr. Sl a t e r a n u Ge n t l e m e n,— I am deeply sensible of th e hon o u r of being placed in th is c h a ir as P re s id e n t of th e London B ranch of th e C h a rte re d I n s titu tio n of B ritis h F o u n d ry m en . My p rid e is g re a te r because ' I recognise t h a t th e occupancy of th is c h a ir is no sinecure. The L o n ­ don B ran ch of th e I .B .F .—th a n k s to th e in d e fa tig ­ able energy an d p erso n ality of o u r h ard -w o rk in g H on. S ecretary , M r. F a u lk n e r—is, to-day, very m uch alive, a n d i t is my in te n tio n , h e a lth and circum stances p e rm ittin g , to d o my u tm o st to f u r th e r th e in te re sts of th is B ranch.

In view of th e fa c t t h a t th e proposed A nnual C onvention of th e m em bers of th e In s titu tio n as p. whole m ay a fte r all very possibly be held n e x t y e a r in th is city, y our officers and C ouncil—and in p aren th eses I m ay say th a t no B ran ch of any p a re n t I n s titu tio n in th e U n ited K ingdom h a s a more loyal, g en ial an d e n th u s ia stic C ouncil—y our officers an d Council a re p a rtic u la rly desirous of e n th u sin g every one of th e m em bers of th e Lon­

don B ran ch to big efforts d u rin g th e n e x t few m onths, so t h a t th is B ra n c h m ay possess t h a t d eg ree of d ig n ity , s tr e n g th a n d co u rag e which m ay well cause envy in th e b re a s ts of th e officers of all th e v is itin g B ran ch es.

W e w a n t to enrol a n u m b er of new m em bers, an d to ro p e in all such as a re qualified a n d d esirab le . I use th e w ord d esirab le in its b ro a d e s t sense. W e m ust n o t fo rg e t th e h o n o u r w hich h as been con­

fe rre d on th e In s titu tio n by th e g r a n tin g of a C h a rte r by H is M a je sty K in g G eorge V ., a n d it behoves us each an d all to p reserv e th e d ig n ity of o u r B ra n c h , an d a t th e sam e tim e to p ro m o te th e in te lle c tu a l w elfare of th e m em bers of th e B ra n c h in accordance w ith th e o b jects of th e I n s tit u tio n as se t fo rth in th e R o y al C h a rte r.

I have a tte n d e d a lm o st every m e e tin g of th e B ra n c h an d also th e C buncil m eetin g s held d u rin g th e la s t tw elv e m onths, an d I am v e ry p leased to b ear te stim o n y th is e v en in g to th e zealous e n erg y of those gentlem en who hold office o r serve on th e Council. The B ra n c h g e n e ra lly owes th e m each a n d all a d e b t of g r a t i t u d e fo r th e ir self-sacrific­

in g efforts, an d fo r th e m an y a tte n d a n c e s a t th e C ouncil m eetings, th e l a t t e r o fte n a t very c o n sid e r­

able personal inconvenience

R e v e rtin g to m y p rev io u s re m a rk s re la tiv e to my occupancy of th e P re s id e n tia l c h a ir fo r th e e n su in g y e a r, i t is n o t w ith in m y know ledge w h eth er, as a m e ta llu rg is t, I am th e first m em ber of my profession to h av e th e h o n o u r o f b ein g placed in th is p o sitio n , b u t I m u s t confess to h a v ­ in g h a d a Little com p u n ctio n in a c c e p tin g th e p o si­

tio n of V ic e -P re sid e n t a y e a r o r so ago, fo re ­ seeing as I d id t h a t th e tim e w ould p ro b ab ly come when, in th e o rd in a ry course of ev en ts, I should be proposed to th is C h air. I fe lt t h a t to t a k e th e office re fe rre d to was to some e x te n t u s u r p in g th e th ro n e of th e F o u n d ry m en , in asm u ch as I am n o t a full-blooded fo u n d ry m an in th e r e s tric te d sense, b u t only a w orks m e ta llu rg ist. B u t a f te r all, w h a t is a m e ta llu rg ist, an d in w h a t re la tio n should h e s ta n d to th e fo u n d ry in d u s try ?

What is a M etallurgist?

T he sh o rte st definition I can offer is, one who is le arn ed in th e science of m e ta llu rg y . T h is defi­

n itio n does p o t ta k e one m uch f a r th e r unless we 178

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a rr iv e a t th e defin itio n of th e w ord “ m e ta llu rg y .”

M e ta llu rg y m ay be defined as th e science of m etals

—com prising th e processes for th e e x tra c tio n o r w in n in g of m etals from th e ir ores, an d for re n d e r­

ing such m etals su itab le for use in th e a rts an d c r a f ts ; likew ise th e processes involved in w orking such m etals, an d th e d e te rm in a tio n of th e physical a n d m echanical p ro p e rtie s of each m etal. F u rth e r, th e processes involved in th e com pounding to ­ g e th e r of tw o o r m ore m etals or of m etals w ith n o n -m etallic elem ents, an d th e stu d y of th e p ro ­ p e rtie s an d a p p lic a tio n of such com plex bodies.

T h e w orks m e ta llu rg is t m u s t be a tr a in e d o bserver an d a n e x p e rim e n ta list. H e m u s t be able to b rin g a keen, a n a ly tic a l m in d to. b e a r upon shop p ro b le m s; he should possess im a g in a tio n and be able to reaso n by in d u ctio n . C o n stru ctiv e critic ism r a th e r th a n d e stru c tiv e criticism should be h is m o tto .

Roll of the Works Metallurgist.

Secondly, in w h a t re la tio n should th e works m e ta llu rg ist sta n d to th e fo u n d ry P T he works m e ta llu rg ist should be re g a rd e d as h a v in g a posi­

tio n com parable w ith t h a t of a K in g ’s Counsel—

w orking w ith a b rief one day fo r th e em ployer, an d on a n o th e r d a y w ith a b rief fo r th e foun d ry forem an, b u t n e v e r assum ing th e r6 le of a crim i­

n a l d e te c tiv e or t h a t of a policem an. H e m u st a t all tim es be able to com m and an d hold th e con­

fidence an d resp ect of b o th h is p rin c ip a ls an d th e w orks staff.

I t m ay be of in te r e s t if I ju s t re c ite a lis t of th e su b jects in rvhich a s tu d e n t m u st q u alify to o b tain th e D iplom a in M etallu rg y of th e R oyal School of M ines, a t S o u th K e n s in g to n :—C h em istry , physics, m ath em atics, m echanics, applied m echanics, a p ­ plied elec tricity , geology, m e ta llu rg y —ferro u s and non-ferrous, assaying— fe rro u s an d non -ferro u s, m etallo g rap h y , electro m e ta llu rg y , hydro m etal- lurgy, ore dressing, physical chem istry, m achine draw in g , fu rn a c e d raw in g an d design, re fra c to ry m aterials, fuel, m ineralogy an d g raphs.

I do n o t believe t h a t th e w orkshop is th e only school in which to receive a tr a in in g , .but I cer­

ta in ly am firm ly of o pinion t h a t th e works m e ta l­

lu rg ist who is c o n te n t to assum e t h a t his college ' tr a in i n g is th e a lp h a an d omega of h is profession,

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an d sh u ts him self u p in th e w orks la b o ra to ry will n ev er m ake an ideal w orks m e ta llu rg ist.

An in tim a te know ledge of th e d e ta ils of w orks p ractice, an d , if possible, a g r e a te r know ledge of h u m an n a tu r e , g lean ed fro m close asso ciatio n am o n g st th e c ra ftsm e n p ra c tis in g th e a r t s an d c r a f ts of m e ta llu rg y , is m ost e sse n tia l if one bids fo r success as a w orks m e ta llu rg ist.

To ask, W h y do you w a n t to know ? before an sw erin g a q u estion, too o fte n causes a n in q u ire r to close u p like a n o y s te r ; w hereas, a w illin g re p ly by th e one addressed will, m ore o fte n th a n n o t, lead to an open confidence, re s u ltin g , fre q u e n tly , in m u tu a l benefit to both p a rtie s . W ith c h ild re n even, one m ay o fte n n o tice t h a t if, w hen a ques­

tio n is p u t, i t is m e t w ith th e w ords, “ W hy do you w a n t to k n o w ? ” th e child rep lies, “ O h ! it doesn’t m a tte r , I only w ondered ” ; m aybe, w h a t m ig h t h av e p roved an in te re s tin g confidence h as been n ip p ed in th e bud.

The Workshop of the M etallurgist.

The w orkshop of th e m e ta llu rg is t is know n as th e lab o ra to ry . The w orks la b o ra to ry should n o t he a~ closed d e p a rtm e n t so f a r as th e fo u n d ry fo re­

m an is concerned. H e should be en c o u ra g e d to seek th e co-o p eratio n of th e la b o ra to ry , a n d th e fo u n d ry fo rem an on h is p a r t should e n d e a v o u r as fa r as possible to k eep th e la b o ra to ry in to u c h w ith b o th th e successes a n d th e fa ilu re s in w o rk ­ shop p ra c tic e . M u tu a l confidence m u s t be e s ta b ­ lished if th e b est o u tp u t is d esired.

I am q u o tin g fro m a le a d in g a rtic le of o n e of th e c o n tem p o rary e n g in e e rin g jo u rn a ls . “ W e m u st ta k e th e In s titu tio n s as we find th e m , a n d a d m it­

tin g t h a t th e y fa ll in some m ea su re fro m p e rfe c t grace, we c a n n o t b u t recognise t h a t even th e I n s t i ­ t u t e of M etals w ould benefit by occasional e le m e n ­ ta r y le c tu re s on th e p rin cip les of th e re la tiv e ly new science of m e ta l.”

If th e I n s titu te of M etals, so also th e I n s t i t u ­ tion of B ritis h F o u n d ry m e n , a n d , if th e I n s t i t u ­ tio n as a whole is to benefit, i t c a n only do so th ro u g h its in d iv id u a l m em bers. T h e re fo re , I am op tim istic enough to Believe t h a t th e L on d o n B ran ch will welcome occasional e le m e n ta ry lec­

tu re s on th e p rin cip les of th e re la tiv e ly new Science of m etal.

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J - O l

What is a M etal?

H as each one p re s e n t h e re th is evening ever p u t pen to p a p e r an d tr ie d to w rite o u t th e definition of a “ m etal ” ?

W h a t is a m e ta l? S urely you w ill agree t h a t th is is cjuite an e le m e n ta ry question, an d y et, a fte r th i r t y y ears in tim a te association w ith “ all sorts an d c o n d itio n s ” of m etals, I confess to being u n ab le to give a re a lly sa tisfa c to ry definition of th e w ord “ m e ta l.” One a u th o r ity h as w ritte n :

“ T he te r m m etal is m ore c o n v en tial th a n s tric tly scientific ’ ’; th e w ord, th e re fo re , does n o t p e rm it of a s tric tly a c c u ra te definition.

Over s ix ty m etals a r e a t p re s e n t know n, y e t as re c e n tly as th e days of good Queen Bess, only seven m etals w ere know n. This s ta te m e n t alone gives some idea as to w h a t w e all owe to th e scien tist.

The possible n u m b er of com binations which can be provided by com pounding to g e th e r tw o or m ore of th ese e le m en tary m etals in v a ry in g p ro p o rtio n s is im possible to calc u late.

W h a t ex actly is o n e to u n d e rs ta n d by th e p rin ­ ciples of th e re la tiv e ly new science of m etals. To answ er th is query in a n y th in g like a sufficiently com prehensive m a n n e r would ta k e m an y hours, And a f a r b e tte r ex p o n e n t th a n myself.

H ow ever, I propose to a tte m p t to e n u m e ra te briefly an d in sim ple la n g u a g e one or tw o of th e m ore re c e n t m ethods of in v e s tig a tio n which have been employed to ad vance th e science of m e ta l­

lu rg y , an d to enable th e p rin cip les of th e re la tiv e ly new science of m etals to be propounded.

Microscopy.

This w ord is derived from th e G reek “ m icro,”

small. The stu d y of th e sm all s tru c tu r e of m a te ria l. You are all fa m ilia r w ith th e rep ro d u c­

tio n s of p h o to m icro g rap h s show ing th e m icro­

stru c tu r e of m etals an d alloys. Almost all th e presen t-d ay li te r a tu r e on m etallu rg ical subjects has its pages in te rsp e rse d w ith m icrographs. Several mem bers am ong us th is evening a re e x p e rt m etallo- g rap h ists. T he value of th e in fo rm atio n gleaned from a stu d y of th e m ic ro -s tru c tu re of a m etal or alloy is now adays recognised w ith o u t question. Do you realise t h a t th is m ethod of in v e s tig a tin g cer­

ta in c h a ra c te ristic s of th e m etals and alloys was only established tw o or th re e decades ago (1894).

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F o r th e m icroscopic e x a m in a tio n of m etals th e su rfa c e of a su ita b le section of th e m e ta l is b ro u g h t to a fine finish by e ith e r filing, g rin d in g , or th e use of v ario u s g ra d e s of em ery a n d o th e r ab rasiv es m o u n ted on cloth o r p a p e r, a n d is th e n p re p a r e d for e x a m in a tio n by one o r o th e r of th e follow ing m ethods :—

lia s R e lie f.—I n w hich th e s o fte r c o n s titu e n ts a re w orn down, a n d th e h a rd e r a re le f t in re lie f.

Polish A tt a c h .— C om bining b o th b as re lie f polish a n d a tta c k by a w eak e tc h in g m edium .

E le c tro ly tic E tc h in g .— 'The specim en b ein g placed in an ele c tro ly te —a liq u id w hich w ill c o n d u c t a n e lec tric c u r r e n t—th e su rface of th e specim en can th e n by su ita b le m eans be e ith e r e a te n aw ay in p a r ts or p la te d in p a rts , w hich serves to d ifferen ­ t i a t e betw een th e v ario u s c o n s titu e n ts .

H e a t T in tin g .-—B y w hich colour v a ria tio n s of th e su rfaces of th e c o n s titu e n ts a re p ro d u c e d , w hich effect is b ro u g h t a b o u t by th e d eg ree of s u rfa c e o x id atio n d u e to th e tim e a n d th e te m p e r a tu r e to which th e specim en is exposed.

T a rn ish E ff e c t.— The d egree of d isc o lo u ra tio n of th e c o n s titu e n ts w hen th e su rfa c e of th e p re p a r e d specim en is exposed to c e r ta in gases su ch as su l­

p h u ra te d h y d ro g en (H ,S .).

O th er m ethods su g g est them selves, a n d a re occasionally used, b u t n eed n o t be e n u m e ra te d .

I n view of th e fa c t t h a t m e ta ls, u n less in e x ­ tre m e ly th i n sheets a re o p aq u e to lig h t, i t is neces­

sary to ex am in e th e su b je c t e ith e r by oblique or v e rtic a l lig h tin g , an d in o rd e r to e x p la in to th e u n in itia te d th e m odus o p era n d i by w hich th e m icroscopic e x a m in a tio n of an o paque o b je c t is possible, m icroscopes an d d ia g ra m s h a v e b een b ro u g h t to th e le c tu re h all, a n d each o n e of you can h av e a p erso n al d e m o n s tra tio n .

T he n e x t q u estio n is, w h a t does th e m icroscope rev eal? I t shows u s (1) G ra in size an d c h a r a c te r ­ istics of th e g ra in , such as core effects, e tc .; (2) th e s tr u c tu r e (p h a se s); (3) c o n s titu e n t m e ta ls w hen o ccu rrin g uncom bined; (4) se g re g a tio n s ; (5) foreign m a t te r ; an d (6) c ry s ta l cleavages, in te r g ra n u la r porosities, gas holes, slip b a n d s, etc.

Macro3copy.

This w ord is derived from th e G reek “ m a c ro ,”

large. T he stu d y of th e coarse s tr u c tu r e , e tc ., of

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m a te ria l. As in th e case of th e e x a m in a tio n of th e m ic ro -stru c tu re , it is necessary to have a p rep ared surface, b u t in th is in stan ce th e su rface, if a polished one, w ill n o t re q u ire to be finished to an y ­ th in g lik e th e e x te n t of t h a t req u ire d for m icro­

scopic e x a m in a tio n . The p re p a re d surface is th e n e ith e r e a te n in to by a n etch in g re a g e n t, or by th e ab rasiv e actio n of some specific m edium used u n d e r pressu re. H e a t effects on th e surface, an d also ta r n is h effects m ay likew ise afford a m eans of d iffe re n tia tin g an d id e n tify in g c e rta in c o n stitu e n ts o r se g re g a te d masses.

In th e first m ethod, th e s tru c tu r e developed, re s u lts from th e re la tiv e degree of solution of th e various c o n s titu e n ts in th e e tch in g fluid. In th e second, i t is th e selective re sista n c e to th e actio n of abrasive w hich serves to d is tin g u ish betw een th e c o n stitu e n ts, an d in th e th i r d m ethod i t is th e re la tiv e r a te of o x id atio n , an d th e d ep th of th e oxide films produced on th e su rfaces of th e various c o n stitu e n ts w hich serves as a m eans of id en tifica­

tio n . In th e fo u rth case, i t is th e discolouring effects of c e rta in re a g e n ts when applied a t norm al te m p e ra tu re s.

Pyrometry.

The th erm o -e lectric couple, or m ore sim ply th e th erm o couple, w as discovered by Serbeck in 1822, b u t rem ain ed d o rm a n t u n til revived by Le C h atelier in 1886.

The ju n c tio n of any tw o d issim ilar m etals when h e a te d is th e s e a t of a n electrom otive force, which is a p p ro x im ately p ro p o rtio n a l to th e te m p e ra tu re . If we u n ite to g e th e r one end of each of tw o w ires and connect th e fre e ends to a d elicate electrical m easu rin g in s tru m e n t— a g alv an o m eter—th e n , upon h e a tin g th e ju n c tio n of th e tw o w ires, a m ovem ent on th e in d ic a to r of th e in s tru m e n t can be observed, an d if th e scale of th e in s tru m e n t is c alib rated to re a d in te rm s of te m p e ra tu re , we have a t ou r disposal a very valuable th erm o m eter.

The g r e a t v irtu e of th e therm o-couple fo r scien­

tific research w ork lies in th e f a c t t h a t th e m ass to be h e a te d is exceedingly sm all. The E .M .F . (electro-m otive force) g e n e ra te d a t th e ju n c tio n by h e a t is a fu n c tio n of th e chem ical com position of th e tw o w ires, of th e d issim ila rity of th e tw o m etals, an d n o t of th e g au g e of th e w ire. F o r hig h te m p e ra tu re d e te rm in a tio n s it is, of course,

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necessary to select su ita b le w ires. T he m ost s a tis ­ fa c to ry th erm o -c o u p le fo r h ig h te m p e r a tu r e m easu rem en ts is m ade by jo in in g to g e th e r a p u re p la tin u m w ire w ith one of a rh o d iu m -p la tin u m alloy (90 p e r c en t. P t + 10 p er cen t. Ro).

P y ro m e te rs of th e therm o -co u p le ty p e are used alm ost exclusively in o b serv atio n s connected w ith physioo-m etallurgy. R eco rd in g in s tru m e n ts g iv in g an a u to g ra p h ic c h a r t are in com m on u se w ith th e ty p e of therm o-couple m en tio n ed above, an d th e tw o in c o m b in atio n afford a v ery a c c u ra te , a n d a t th e sam e tim e fa irly ro b u st scientific in s tru m e n t.

T he use of th e therm o-couple p y ro m e te r fo r r e ­ searches in p h y sico -m etallu rg y , a n d th e a p p lic a ­ tio n of th e m icroscope fo r th e e x a m in a tio n of m etals, m ay be said to b e th e tw o p re d o m in a te fa c to rs m a k in g possible a n d le a d in g to th e in tr o ­ d u ctio n of th e new er science of m e ta llu rg y .

Utility of Pyrom etry.

A m ongst o th e r d e te rm in a tio n s , w ith th e th e r m o ­ couple, one can m a k e : —

(1) A cc u ra te d e te rm in a tio n s of th e m e ltin g p o in ts (freezin g p oints) o f each of th e e le m e n ta ry m etals.

(2) The th e rm a l effects ta k in g p lace d u rin g th e tr a n s itio n from th e wholly liq u id to th e wholly solid s ta te s an d vice versa of th e alloys.

(3) T he th e rm a l effects ta k in g p lace in solid alloys when cooled from above o r w hen h e a te d above o r cooled below th e n o rm a l te m p e r a tu r e .

Finding Melting Points.

I f we im m erse a therm o-couple, s u ita b ly p ro ­ te c te d , in to a sm all m olten m ass of an e le m e n ta ry m etal such as p u re copper o r iro n , an d rem ove th e m olten m ass from o u t of c o n ta c t w ith th e source of h e a t em ployed in m e ltin g th e sam e, th e m e ta l will g ra d u a lly cool dow n, a n d th e in d ic a to r connected w ith th e therm o -co u p le w ill c o n tin u e

I f we im m erse a therm o-couple, s u ita b ly p ro ­ te c te d , in to a sm all m olten m ass of an e le m e n ta ry m etal such as p u re copper o r iro n , an d rem ove th e m olten m ass from o u t of c o n ta c t w ith th e source of h e a t em ployed in m e ltin g th e sam e, th e m e ta l will g ra d u a lly cool dow n, a n d th e in d ic a to r connected w ith th e therm o -co u p le w ill c o n tin u e