The Iron Age 1940-09-19: Vol 146 Iss 12

SEPTEMBER 19,1940 VOL. 146 NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager Managing Editor Editor Technical Editor Machine Tool Associate Associate Editor Editor Editor Art Editor Editor Emeritus Washington Editors MOFFETT JAMES ELLIS Resident District Editors CAMPBELL ROBERT BINGHAM Pittsburgh Chicago Cleveland Detroit Editorial Correspondents Buffalo Cincinnati FRAZAR CHARLES POST Boston San Francisco HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON ROY EDMONDS Toronto, Ontario St. Louis LEROY ALLISON Nework, Editorial Technical Articles Grading Abrasive Stick Rockwell Fluorescent Lighting for Accuracy Finishing Dies and Molds Steel Engineers Await New Steel Mill Machine Tool Improvements Feature Reports News and Market Reports News Industry ........... Machine Tool Activity 126 Personals 112 Non-Ferrous Metal Market 127 Obituaries Scrap Market and Prices 128 Metal Working Activity 115 Construction Steel 130 Comparison Prices 116 Iron and Steel Prices Summary the Week 117 Pig Iron Prices 137 The Industrial 118 Warehouse Prices District Market Reports 120 Sales 140 Copyright, 1940, Chilton Company A. H. DIX, Manager Reader Service Owned and Published by CHILTON COMPANY (Incorporated) Advertising Staff Publication Editorial and Emerson Findley Office Executive Offices Robert Union Chestnut and Séth Sts. East 42nd Hottenstein, 1012 Otis Bldg., Chicago Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd New York 428 Park Bldg., Pittsburgh OFFICERS AND DIRECTORS Don Harner, 1595 Pacific Avenue, Long JOS. HILDRETH, Vice-President Beach, Cal. GEORGE GRIFFITHS, Vice-President VAN DEVENTER, Vice-President Member, Associated Business Papers lished every Thursday. Price: JOHN BLAIR MOFFETT, Secretary United States and Possessions, Mexico, Cuba, JULIAN CHASE, THOMAS KANE, Cable Address, "“lronaqge, HARRY V. DUFFY CHARLES J HEALE 7 ; = 2 3 an 7 { | 36—THE IRON AGE, September 19, 1940 Illustrations show Mahon Roll- ing Steel Doors installed in the Chevrolet Foundry Bidg., Sagi- naw, Mich., Pacific Gas & Elec- trie Company's plant, Herndon, California, and the Ap- praisers Stores, Chicago, Ill. Inset is the unique and very compact Mahon Standard Power Operator. STANDARD Quality and Dependability Mahon Rolling Steel Doors are now service every type building throughout the width and breadth the they are built last lifetime, and, being modern every detail, they have many new features not obtainable any other make door. The Mahon Power Operator, for instance, offers distinct advantages design and operation—all gears the mechanism are enclosed oil-tight gear-box and run bath oil the auxiliary emergency chain-gear operator does not drive through the motor shaft, common practice other power operators. All other operating and automatic mechanism that into Mahon Standard and Underwriters Labelled Doors are equally modern. Write for complete catalog, see Sweets. THE MAHON COMPANY DETROIT, MICHIGAN Representatives Principal Cities. += 4 | A SEPTEMBER 19, ESTABLISHED 1855 Men Machines? other day saw man busily engaged driving nails into plank. Now, ordinarily, one would pass instance this kind with little attention. But this case, aroused curiosity because was not nailing the plank anything. was just filling full nails. stopped and inquired what was going had driven all the nails into the plank. said, going start pulling them out That, seems me, the position that find ourselves today. Here are turning industry upside down and almost inside out order make changeover from peace prod- ucts war products. Here are devoting most our energies building planes and guns and tanks and battle- ships which hope will never have occasion use against anybody and that nobody certainly wants have use against them. And after the emergency has passed, everything passes time, will all have get busy reconverting our industries back peacetime products and production. and large, it’s harder pull nails out plank than drive them in. harder create new wealth than destroy old savings. And that exactly what when embark upon war the preparation for it. want and need keep our industries this country position solvency they can hire back the boys who war who are conscripted for peacetime training. Also, will need them create new wealth pay for what spend for battleships and tanks. Democracy cannot shoulder the burdens what going today unless puts itself upon new and substantially lower cost level. can that only two ways: taking out men getting out machines. The latter way may save Democracy, the former will not. The latter our way, the American way land free men. The former 4 4 { Pas we a & ~ = ame | re) ¥ . 7 4 > | When Unit Values Are High Assure Low Forming Costs With Inland Sheets ACH stroke press represents dollars expended for fixed charges, labor and overhead. That why the greater the number operations per- formed complete part, the higher its unit value. When breakage occurs all the value put into part, including the cost steel, wasted. many leading manufacturers who use Inland Sheets made especially meet their fabricating and product require- ments. Inland metallurgists will gladly cooper- ate solving your sheet forming prob- lems. Their services are without obliga- tion. Call write your nearest Inland This loss being held the SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS Processing Trends Powder made me- tallic powders are rap- idly expanding scope application improving physical charac- teristics. Today, many articles are being made from pow- ders more cheaply and better than other manufacturing methods. This article points out this expanding applica- tion and lays down limita- tions. Data also sented methods mak- ing powders, manufacturing technique for the articles, and metallurgy and physical characteristics the various metallic combinations. technique producing ob- jects metal known “powder metallurgy” “metal ceramics,” special field metallurgical engineering which becoming more and more important industry. The process allows the production solid metallic articles from finely divided metallic powders without subjecting them general melting and casting procedure. The powders are merely compressed high pressures and subsequently simul- taneously heat treated temperatures below the melting point the main constituent way similar that used the manufacture ordinary ceramics. this way, metal powder compacts can produced either semi-finished finished commercial for subsequent metal working proc- ess such rolling, swaging, drawing, stamping, etc., which will ultimately ° ° PAUL SCHWARZKOPF and CLAUS GOETZEL President Respectively, and Powder American Electro Metallurgist, Metal Corp., Yonkers, yield wires, sheets, tubes and other special shapes and forms. First attempts produce solid metal bodies were carried out platinum hundred years ago, but this new art became successful only the turn the century, when was adopted for the manufacture refractory metals such tungsten and molybdenum. These materials were difficult melt that the compacting and sintering method was the only solution the problem. There followed period rapid development manufacturing procedures which immediately found new applications the production tantalum and other tantalum products, the manufacture hard metals and compound-contact metals and the production metal parts lower melting metals and alloys. Today there are many articles made metals and alloys, from tungsten and titanium down aluminum, cadmium, tin and lead, which can produced successfully from powders. sheets Present Uses The first application, the replace- ment inconvenient difficult casting process, has already been men- tioned. The new method manipulations much lower temper- atures than necessary for melting procedure, and even the highest melt- ing refractory metals can readily sintered means relatively easily constructed apparatus, sometimes using commonly equipment. Tungsten, for instance, can produced wire form press- ing powder into bars and subsequently sintering direct current resistance heating under protective atmospheres temperatures far below the melting point. The sinter ingots obtained this way are then worked down rods which ultimately may drawn wires fine they may used for incandescent lamp filaments and heat- ing wires radio Such wires are known have tensile strengths from 500,000 600,000 Ib. per sq. in. The use two more different metal powders produce composite metals retaining the individual char- acteristics each constituent an- other application. The so-called “heavy metal” which contains per cent tungsten and the balance copper and nickel, one example. When the dif- ferent powders are mixed, pressed and sintered, the finished product has density about and suitable for balancing parts, etc. industry generally makes use similar composite mate- rials, known “compound metals,” produce contact materials and welding electrodes which combine tance fusion and volatilization arcing temperatures such metals THE IRON AGE, September 1940—39 wer or = % . — 4 cost “aed molybdenum and tungsten with the high conductivity copper and silver. Powder metallurgy makes possible incorporate these high melting met- als the lower melting conductors, and thus reduce efficiently the ten- dency these contacts fuse with- out destroying conductivity. One the most important applica- tions powder metallurgy com- bining metals and non-metals. Many examples could given. One the production which are used the manufacture high speed cutting tools. this proc- ess, the powder the heavy metal which usually tungsten, tantalum titanium, combined with some form carbon produce the hard and brittle metallic carbide. cobalt When these binders are used, some toughness and resistance shock added the extreme hardness the carbides. Another application this group copper and graphite com- bination which used the electrical industry for collector brushes. Recent- new grinding and cutting tools have been developed impregnating hard metal, nickel, bronze other metal powder compacts with diamond dust. The metal compacts form tough and somewhat ductile matrix which the diamond particles are held place. Another very important advantage metal ceramics the fact that permits the production metallic bodies with definitely controlled porosity. This has led rapid de- velopment the so-called self-lubri- cating bronze bearings, one the main products non-ferrous powder metallurgy. Copper and tin, which may added small percentages are pressed into bearing shapes, and these compacts are sin- tered protective atmosphere. The finished bearings possess porosity per cent volume. One the most promising applica- tions powder metallurgy the large scale production small, standardized metallic parts. Since, many cases, these parts can directly compacted into their final shapes, the high costs machining are saved. Recent progress the developing and mar- keting the necessary raw materials, such iron and steel powders, opening great field application the automotive industry. There are numerous other applica- tions which can only intimated this paper. The ability combine metais which are not miscible the liquid solid state form uniform compacts has led the development 40—THE IRON AGE, September 19, 1940 The relative copper-lead bearings. ease machining semi-sintered pow- der compacts has facilitated the manu- facture permanent magnets from metal powders, and the possibility molding subsequent layers different products may also open new field industrial application. Processing Principles There are number different methods for the manufacture metal alloy powders, the more important which are mechanical disintegra- tion, gas-reduction, electrolysis, precip- itation, condensation and chemical dis- placement. Mechanical disintegration may done crushing, stamping grinding. Powders thus obtained are prepared for processing drying, re- ducing, mixing ball milling. Vari- ous grades can produced commer- cially and depend the shape par- ticles, the screen analysis, the flow and Diagrammatic Sketches Physical and sintered metal — Compacting pressure Compacting pressure Theoretical valve o v Compressive strength pressed Compacting pressure Compacting temperature Sintering temperature sintering time the apparent density, all which are important factors governing the quality the finished metal part. The metal powder, whether alloy, plain metal metal mixture, usual- fed into steel die and compressed into compacted bodies. some cases with iron carbonyl the powder need only fed and tapped into mold tube. The dies and punches are usu- ally made hardened steel resist high pressure and require most accu- rate fitting. The molds are then placed presses, either mechanical hy- draulic. Either hot pressing cold pressing methods may employed. Hot pressing usually performed such temperatures that reducing at- mosphere required. This process sometimes eliminates the sintering op- eration because pressing and sintering are done simultaneously. This method well worked out for the refractory metals but relatively new for low- melting materials. Sintering temperature sintering time tal | | | | Cold pressing specimens are usually heat treated. This treatment called sintering annealing and develops crystalline structure from the com- pressed agglomerate powder parti- cles which were previously held to- gether only adhesion forces. The metamorphosis the powder compacts into metallic bodies assisted co- hesion forces the particles caused their being strained during compres- sion. heating, the strains are re- leased and recrystallization and, later on, grain growth play the main part the conversion the compacts into regular metallic bodies. The more closely the sintering temperature ap- proaches the melting point, the more does the solidification the compact idvance until the structure the or- dinary material finally approached. The sintering time well the rate heating and cooling depends the material. Commercial sinter- ing periods range from few minutes Q Hardness, tensile strength, Density | Grade initial powder n,rollability, strength Elongatio Density ing, sintering follows the diffusion laws for the solid state. decrease time necessitates increase sinter- ing temperature establish the same degree metallization the powder compacts, and vice versa. avoid surface oxidation, reducing neutral, sintering atmosphere must used. This may gas, such hydrogen, carbon monoxide, dis- sociated ammonia nitrogen; vac- uum; liquid salt such cyanide low melting metal. the reduc- ing medium gaseous, must dry condition. increase the density and physical properties the sintered metal, heat treatment the compacts often fol- lowed subsequent working such repressing coining, forging, swag- ing, rolling, drawing, etc. Repress- ing often employed for bearings and bushings and done either the original mold different die Processing for Metallic Powders impact Density ~s Processing obtain the final shape the piece. The applicability repressing, which not always essential even possible, de- pends upon the material and the shape desired. Some materials expand contract during sintering such extent that repressing becomes ex- tremely difficult. Other working meth- ods are general use for the manu- facture lamp filaments, sheets, con- tact points, etc., from compacts con- sisting either entirely substantially refractory metals. They can also successfully applied lower melt- ing metals, such copper, iron and nickel and their alloys, the labora- tory research. Metal Synthesis During compression, the powder particles are brought close together that adhesion forces come into effect. The greater the number contact points established, the larger the sum the adhesion forces. There- fore, fine powders have better ad- herence after pressing than coarse powders compressed the same pres- sure. Briquettes compacted cer- tain pressure from powders soft metals, such tin, lead copper, are more rigid than compacts compressed the same pressure from hard metal powders the refractory metal and carbide group, because the soft metal powders are more plastic under the compacting pressure and provide more contact areas for action the cohesive forces. the other hand, the hard powder particles are not plastic and therefore result brittle compacts, that auxiliary cementing materials must used. The consolidation the compacted powder particles caused the atomic mobility the metal ele- vated temperatures. The cohesive forces are replaced atomic inter- locking takes place within the particles and their borders form new, artificial grain boundaries. With further rise tem- perature, grain growth, caused co- alescence, results shifting the new grain boundaries and the grad- ual disappearance the old powder particle interstices. The more advanced this metamorphosis becomes, the closer does the compact approach the regular metallic state annealed casting the same metal. The grain size the synthetic metal usually much finer and can controlled the grade the initial powder and the temperature and the duration heat treatment. case sintering al- loys composited metals, inter-diffu- sion another phenomenon which accompanies recrystallization and THE IRON AGE, September Poy | 3 - 2, i Ga grain growth. causes the type bonding which effected the cementing action constituent which molten the tem- perature the consolidating sintering operation. Pressure when applied the com- pact while cold will lower the recrys- tallization temperatures, but has only indirect bearing the final grain structure since merely condenses the loose particles more less porous The porosity remaining these aggregates after compression partially governs the structure the final compacts. Grain growth may close change some the cavities, but the extent again largely depen- dent the type initial powder and the kind heat treatment. aggregates. the physical properties the final material. The type and shape the individual cavities are the great- est importance. Porosity originating from imperfect compacting tically always present but can par- conditions. The detrimental effect this imperfect treatment the qual- ities the final compact caused the shape the cavities which are usually angular but not infrequently continuous. Porosity developed dur- ing sintering due gas evolution equal importance, although these pores often have more regular and usually spherical shape with less influence the mechanical properties the final compact. This secondary porosity particularly fa- vored fine particle size the initial powder and treatment. With sufficient time permitted for ,complete expulsion air entrapped during compacting and gas ad- sorbed the initial powder, the atom- forces during sintering elevated temperatures will promote shrinkage the metallic sponge into dense metallic body. This depend largely the fineness the initial powder and the temperature and duration sintering. Although exces- sive shrinkage inconvenient with regard sizes and tolerances the compacted bodies, the main indi- cation successful consolidation the powder compacts. Impurities also have their effect the degree metallization and the mechanical properties the compacts. Three types impurities may dis- tinguished: thin films surrounding the powder particles such oxides carbonaceous substances, small foreign particles impurities usually found 42—THE IRON AGE, September 1940 the walls angular cavities and already attached the initial powder particles, and isolated inclusions such silica other oxides can- not readily reduced. cases, the films impurities are the most harmful, especially since they hamper prevent the atomic mobil- ity, grain growth and diffusion. This definitely the case with the oxide skins magnesium, aluminum and chromium powder particles, which are However, there are cases known which oxide films surrounding the par- ticles slight amount oxygen chemically bound the main mass the metal powder, are beneficial in- fluence. This the case tungsten. Oxygen-free tungsten can- not sintered easily. the other hand, powders with small content bound oxygen with oxide film sur- rounding their particles are very suit- able for the sintering process carried out hydrogen hydro- gen containing atmosphere. Hydrogen reduces the tungstic oxide nascent tungsten with high vapor pressure, which settles down the original tungsten particles and provides arti- ficial bond cement the particles to- gether. The influence the other types impurities the metalliza- tion and physical properties the compacts will probably depend their quantity, their character and their dis- tribution. Impurities such silica, thoria, alumina, magnesia, which are not reducible hydrogen temperatures, have marked influence the phys- ical properties the final products, even the impurities are present only the grain boundaries small amounts. Properties Compacts The properties the powder com- pacts are strictly dependent the state the briquettes and the his- tory their processing. logical that briquettes, agglomerated pres- sure but not subjected any heat treatment, have characteristics differ- ent from those which have been sin- tered, and that those which were only slightly compressed before heat treat- ment have properties other than com- pacts which were subjected high pressures before heat treatment were pressed and sintered simultane- ously even severely worked after heat treatment. Probably the greatest influence the final qualities the compacts exerted the specific ma- terial used basic powder. One can- not expect that lead powder compact will yield hardness similar cast iron chromium that chromium titanium powder compact will have ductility comparable that cast copper. Nevertheless, might justified make attempt generalize the trend the properties compacted metal powders the basis research data far known. Most the information must derived from the refractory metal and the cemented carbide field, but there available suf- ficent information from the field lower melting metals and alloys al- low certain generalizations and con- clusions made. Compacted but not heat treated met- powders are very brittle and weak. They are the stronger, the higher com- pressed and the softer powder is. The strength direct function the adhesion tween the particles. Hardness these compacts governed the degree strain hardening the powder bri- quette during molding, the natural hardness the metal and the degree density the compact. The den- sity, the other hand, chiefly in- fluenced the compacting pressure, but also depends the plasticity the powder and the size the parti- The more advanced the heat treat- ment is, the more nearly sintered metals approach the state annealed metallic castings the same material. increase compacting pressure, sintering temperature sintering time the static properties may approach the values the ordinary metal, some cases may exceed them. The same holds for other physical charac- teristics such density, electrical and heat and ductility are also influenced same factors but less marked de- gree since they are main functions the conditions the artificial grain For this reason such prop- erties rollability tensile elonga- tion, reduction area drawing abil- ity cannot considered “density controlled” properties, static properties sintered metals may well classified terms. Dynamic properties such impact resistance show behavior sim- ilar ductility and malleability. The properties compacts which are pressed and sintered simultaneous- have not yet been studied thoroughly those bodies which are first compacted and then sintered. However, known that the static properties are much easier improve and much faster bring maxi- mum this method used. Evidently, j | the combination pressure and heat results reinforcing effect each other, and the metamorphosis the compacts achieved lower tem- peratures much less time The im- proved plasticity the hot-pressed briquettes permits density approach its theoretical value, thus diminishing the detrimental porosity and granting intense atomic action between neighboring particles between new- formed grains. This not only affects beneficially all “density controlled” properties, but also very proves static elongation and dynamic impact resistance. Very remarkable the great hard- ness powder compacts which are compressed high pressures when heated temperature slightly below the recrystallization temperature. This hardness excess the values ob- tained for the same compacts pressed room temperature, and may far ex- ceed hardness values ordinary ma- terial severely strained cold work, the initial metal powder very fine grade and the material belongs the class soft and ductile metals. Present Limitations Powder metallurgy today has limitations several directions which apply most its operations. First the question economy. Metal powders are yet more expensive than cast metal ingots. result, sintering process which absolutely necessary and economically sound the manufacture parts made from tungsten, molybdenum their carbides, may entirely out the question the case small, inex- pensive steel brass parts for the automotive general machinery. The question equipment cost equal importance. The powders are molded into suitable designed dies. These dies must strong and well built. Since tons per sq. in. and higher, are used, necessary employ powerful and expensive presses. The unit compact- ing pressure may considerably re- duced the application heat dur- ing pressing, thereby taking advantage the better plasticity the metal powders. However, the necessary dies must constructed special heat- resisting steels which, again, are more expensive. this case, also, unit pro- duction rates will than the case cold compacting and subsequent sintering, because the time the heating and cooling cycle each compression must sidered. Another limitation largely me- chanical. The size the compacts Commercial copper powder. di- ameters. Same powder above compacted tons per sq. in. 200 diameters. Cc Same powder com- pacted and sintered 750 deg. for hrs. hydrogen. 200 diameters. Same pressed 400 deg. tons per sq. in. 200 diameters. . rr Sintered copper powder compact after cold rolling and drawing wire. Annealed. 1000 diameters. THE IRON AGE, September controlled the capacity the presses which is, course, limited. Furthermore, the size the speci- mens also limited the compres- sion ratio the particular powder which might fall the range between 2:1 and 20:1. Since metal powders not behave perfect liquids under pressure due the friction between the particles themselves and between the particles and the die walls, the shape and size the final compacts confined certain more less simple configurations. The depth the briquettes particularly trolled these factors. Thermal limitations also are considered. Certain oxides, that tin for example, are known reduce- able only temperatures well above the melting point the metal. -Con- sequently, tin powder particles, once they are enveloped oxide films, will maintain these films during sintering which must carried out below the melting point the metal. The films, however, have most detrimental ef- fect the rate metallization the compacted powder aggregates and are probably the chief reason for the poor sintering ability and extreme brittleness such low melting powder compacts tin, bismuth, cadmium, lead and zinc. Finally, there remain certain basic limitations the characteristics compacts Most these limitations are closely connected with the degree and type porosity the compacts, with the particular conditions the newly formed grain boundaries. Porosity cannot avoided the customary sintering procedure carried out, but can considerably reduced pres- sure and heat are ‘taneously during the molding opera- tion. Porosity limits all static, properties, but this limitation can overcome close approach the apparent density the sintered compacts the theo- retical value. Tensile elongation and impact resistance, however, are gener- ally low, since these properties are mainly controlled the specific con- ditions the grain boundaries. New Possibilities and Trends More rapid advance the field powder metallurgy may expected and work overcome some the obstacles powder research will cover many fields. The raw materials from which the powders are prepared will im- proved that the resulting products may more carefully controlled. The 44—THE IRON AGE, September 1940 regulation compacting heat treating equipment will improved and hot-pressing will become dustrial Further work continuously operating machinery will done and unit equipment for com- pacting, heat treatment working, will developed. finally, advances will made con- verting the raw sintered compacts into refined, semi-wrought material. present, the use pre-alloyed powders basic material rapidly developed. (G. Comstock, Metal Progress, 35, 1939, 343.) The advantage their use evident. Sintering time can considerably re- duced and the promotion secondary porosity gas evolution due the reaction the ingredient metals can avoided. Also the expansion the compacts during heat treatment can greatly limited. Alloy powders are obtained directly from the raw ma- terial the reduction ores which contain the alloying ingredients, spraying atomizing the molten al- loy, direct electrodeposition the alloy powders, subjecting metal powder chemical displacement process, subjecting mixture the individual metal powders pre- treatment which will refine the pow- ders and will diffusion, and the use foreign gaseous phase the heating chamber. method for converting ore powder into soft, compressible car- Patent No. 2,175,850. The other meth- ods just mentioned are suitable for the production many commercial non-ferrous alloy powders. The raw material problem naturally closely related the type pow- der production. Recent development work iron powders (L. Wyman, Metal Progress, 35, 1939, 585), only one example the careful and methodical attack develop basic ma- terials for powder metallurgy which are inexpensive and still good enough allow competition between the sin- tered articles and machined parts die castings now commonly used. sufficient purity the powdered ore concentrate and proper conditioning the resulting metal powder are primary importance for producing final products good quality. Remov- impurities and close check the powder particle surface conditions are basic necessities which cannot over- looked during the early stages processing. trolled equipment may considered natural consequence time, and there little doubt that many the mechanical obstacles, mentioned above, will overcome the near future. Standard powder metallurgical processing equipment will become less expensive the more the experience and skill die making metallurgical equipment advances. quency induction current for powder work hold great posibilities for the development the heat treatment end the processing problem. The acceptance hot-pressing procedure for lower melting powder metallurgical objects probably greatest significance. This procedure well known and successfully used the metal carbide field and the in- dications are that with certain skill the method can well used indus- trially for lower melting metal pow- ders. After the establishment re- liable research data the influence pressure and heat the increase the plasticity certain metals and alloys, the problem selecting and designing the proper die should not offer many serious diffi- culties. has already been stated that the physical properties the final prod- uct depend largely the character the grain structure which has de- veloped during the application heat. matter fact, the importance heat the formation the artificial bonds sintered bodies similar that the development and main- tenance the inter-crystalline bonds cast metal. Comstock, dis- cussing the question the bond, de- fends the hypothesis that cooling from the plastic the solid state ap- parently sufficient for the propagation of. atomic bonds between contacting metal particle surfaces, whereas for cast metals inter-crystalline bonds are initially produced cooling from the liquid through the plastic the solid state. Cemented metallic bodies with constituent molten the sintering temperature take intermediate place between the regularly sintered bodies, which are completely the solid state, and cast metals. Comstock’s view that bonding between solid metal par- ticles and molten metallic cement seems depend upon the metallicity and partial solubility the unmelted constituent. Therefore, solution al- loying, involves the formation new atomic arrangements and fulfills con- ditions similar those present during the formation the initial crystalline bonding cast metals. For these reasons direct compari- son between sintered bodies and cast- ings seems permissible metallurgical practice applied cast | | | ingots may also employed sin- tered metals. other words, can expected (and already proved the case the ductile refractory metals) that refinement the grain structure the application work will great significance for sin- tered metals general. The impor- tance this conclusion has been rec- ognized the refractory metal field since its earliest existence, logical transfer all other branches powder metallurgy has started only recently when became evident that the typical brittleness, shortness tensile elongation and weakness im- pact resistance ordinary sintered metals was too great obstacle overlooked discounted. The recently developed practice applying kneading operation the metal powder while being com- pacted, opens great field research. The adoption standard metal work- ing methods such swaging, rolling, forging and drawing, will com- paratively easy and the experience gathered from the ductile tungsten, manufacturers will most valuable for satisfactory processing other powder metallurgical materials. How- ever, the final success this new pro- cessing scheme will depend largely the possibilities incorporating the metal working process the general processing cycle order guaran- tee continuous operation. New de- velopment work will done the building equipment units which pressing, heating and working the material. Patent No. 2,148,040, for instance, gives excellent method. The sintered hot- pressed powder compacts jected extrusion process which refines and condenses them, and final- converts them into wrought-like state. Future Applications expansion the field appli- ciation will depend largely success- ful solutions the many problems in- dicated this paper. The develop- ment babbitts from metal powders will depend the successful applica- tion hot-pressing and the removal complete avoidance oxide and other impurity films around the pow- der particles. The latter will also basic condition for the successful development aluminum and zinc al- loys substitutes for die castings. Commercial hot-pressing will open the door for the manufacture high- duty copper alloy parts, such wash- ers and bushings, and, last but not least, for the industrial development strong and tough iron and steel parts from metal powders, develop- ment which has been eagerly awaited for years. Other possibilities may found the development ductile wires from brittle metals such ti- tanium, electrical resistance ele- ments such iron-chromium, nickel- chromium and other alloys. And, finally, the refractory metals may find many new uses the production new tool metals, electrical contact metals and wear resistant parts. Hypercarb Process Gas Carburizing Continental Industrial Engineers, Inc., Chicago, was described Darrah the 100th meeting the American Chemical Society, Detroit, Sept. 12. The process serves apply controlled high-carbon case steel articles. depends treating steel articles controlled temperatures for controlled time atmosphere con- taining hydrocarbon and carbon mon- oxide controlled percentages. Following extensive tests Con- tinental the carburizing process and muffle made refractory material, study was made the possibility pretreating and preactivating the gases for carburizing. far known this was new field and has given very interesting results. was found that heating the carburizing gases temperatures the order 1600 deg. 1700 deg. prior permitting them come into contact with the steel being treated, very rapid carburizing ac- tion was obtained and the gases acted many respects they were much more active than unheated gases. further interesting result was the fact that the gases thus pretreated did not deposit carbon scale soot the steel being treated and was possible the proper pretreatment the gas bring out steel articles which would entirely clean and bright while hav- ing decided carburizing effect the surface the article. further study this process seems indicate that the preheating the carburizing gases developed especially active compounds most which appeared contain carbon monoxide some form. was further developed that the action free carbon such soot coke depositing from the carburizing gases was very slight combining with the The general results this investiga- tion tended indicate that the carbon which combines with steel under ordi- nary practical temperatures and work- ing conditions usually the form combined carbon monoxide. Indica- tions were present that carbon monox- ide formed intermediate compounds with iron, nickel and some other metal and that these intermediate compounds act carrier. The net result the investigation was develop commercial process which now operating auto- mobile plant. The process quite rapid and gives absolutely clean and uniform surfaces with controlled car- bon contents. possible run the carbon con- tents the surface high 1.2 per cent carbon. controlled soaking time and controlled gas com- position this may reduced in- creased depth the case con- trolled will, according Mr. Dar- rah. THE IRON AGE, September 19, 1940—45 { £4 “< —Where aluminum dreams are trans- lated into fact. Described here are some the historical innovations the fabrication aluminum. name five interesting types aluminum fabrication, and chances are that would glibly mention casting, forging, rolling, drawing and extruding. Most likely would forget all about the work that being done the jobbing division, the oldest plant the Aluminum Co. America New Kensington, Pa. the jobbing division articles are made which cannot, for one reason another, fabricated other progressive department which alu- any minum dreams are translated into fact. Many aluminum success was first developed there. For the past years the company personnel has known the “job shop,” and the functions the job shop date back earlier. They began when, for the first time, the company fabricated aluminum article for Company his- torians place this date somewhere around 1895, The company had been founded 1888 under the name the Pittsburgh Reduction Co., and its original inten- tion had been manufacture such semi-fabricated products ingot alu- 46—THE IRON AGE, September 19, 1940 minum, castings, sheet, rod, According the plan these were made into finished articles other manufacturers. But world obsessed the “alu minum fever” the plan did not work. The “aluminum fever” was industrial disease quite common the nineties. Its victims believed that al- most anything could made success- fully aluminum. The metal was one the most precious science the nineteenth century, and enthusiasm over its light weight, its high resistance corrosion, its new high heat and electrical knew bounds. must recalled that aluminum was not always the inexpensive 18c.- metal today. Aluminum was not even known prior the day 1825 when Hans Christian Danish scientist, made the first globules aluminum. Its cost, be- cause expensive reduction methods, was exceedingly high. 1852, for in- stance, pound aluminum sold for $545. Improved production methods had brought this price down per 1885, but this was still far too high allow aluminum used quantity. Charles Martin Hall, 22-year-old Oberlin College graduate, discovered electrolytic process which alu- brought his invention the atten- tion group Pittsburghers, who founded the Pittsburgh Reduction few years the “aluminum began. Joseph Allison Steinmetz, the Philadelphia firm Jamey and Steinmetz, wrote the October, 1900. Aluminum World: “The new, white metal, aluminum. Houses, bridges, and locomotives built it. and steel, metals the past, with the great ‘Aluminum Age’ drawing upon us!” Steinmetz may have appeared his contem- poraries incorrigible visionary, time eventually corroborated many his great, There was much made aluminum! however, were reluctant assume the responsibility development, and al- though the Pittsburgh Reduction Co. stood ready give every amount technical advice possible, not much progress was made first. The world industry, however, de- manded aluminum, and soon learned beat path the door the Pitts- burgh Reduction Co. 1900 num- fully fabricated products were made the machine shop the New Kensington works. The company then formulated policy which has generally ad- hered the past years. would develop product and then share the fabricating experience with interested responsible firms. The manufacture aluminum cook- ing utensils was the first—and also policy. While the company never gave the manufacture aluminum cook- ing utensils after they were once de- veloped, served popularize them such extent that scores com- panies are now doing business making utensils. Some them have even en- larged their activities the point where they manufacture other alu- minum commodities, such sheet. chronology job shop activities shows that early 1901 interior panels, brackets, and moldings were made there for the Interborough Rapid Transit Co. Real impetus came the end the when number I | | automobile bodies, among them White, White Steamer, Peerless Toledo, were constructed aluminum the job shop. 1904 more than 100 men were employed the automobile depart- ment alone. 1912, the Ford Motor standardized aluminum hoods, and many 3000 them were made New Kensington single working day, and the Ford hood was one the principal products the shop for several years. “Can you weld aluminum?” one the questions frequently asked aluminum engineers. The question was first the job shop the initial years the present century, and the technique gas welding was devel- oped. The job shop went further, that today other forms welding alu- minum, such spot, seam, and resis- tance welding are commercially prac- ticable. 1914 the activities the job shop had expanded such extent that the erection new building was necessary. was two-story struc- ture, amply large accommodate the augmented force and additional equip- ment. Soon, however, working space was filled capacity, partly accounted for the British and Belgian war orders for steam- this same year orders were re- corded for varnish kettles ping drums. Rayon spinning buckets, which many are now alu- minum, were first made Alu- minum running boards were made for the Studebaker 1915, and later that year the shop went into production Marmon hoods, fenders, and gasoline tanks. 1917, the facilities the job shop were devoted almost exclusively the manufacture military sup- plies, airplane parts, and equipment for wartime chemical industries. After the war, when rayon began come into its own, spinning spools and cake centers were made. manner which product was de- veloped the job shop may seen from its venture into the manufacture aluminum furniture. The late Mellon, president the Mellon National Bank Pitts- burgh and once president the Alu- minum America, had become thoroughly infected the aluminum first tank car made was built for the Cleveland Cliffs Co. 1927. The car, used for the transportation acetic acid, was made the job shop the Aluminum Co. eight tank sections, since was built prior the Interstate Commerce approval standard constructed single tank car aluminum. Two others similar de- sign were made the same time and have now seen years service. They are good condition and are expected last least years longer. start large aluminum tank made the job shop. section aluminum plate put through bending brake and given the proper curvature, and then the heads, shown the background, which have been previously spun size, are welded on. THE IRON AGE, September 19, 4 4 € o~ afte fever. due the credit for first thinking about ture. also gave the job shop the first order for When his bank moved into new quar- ters 1924, the banking floor the new building contained 100 aluminum and 300 aluminum chairs, The lightness the chairs, their easy portability, and their sturdiness (all joints are welded, thus chair can ever become loose creaky) made instantaneous hit. The Phila- delphia Free Library ordered 700 alu- minum chairs, followed order for 1000 dining car chairs the Pennsylvania Railroad. This instan- taneous success caused the Aluminum Co. approach various manufactur- ers furniture, suggesting that alu- minum furniture had future and that this future could assured intelligent development, manufactur- ing, and selling campaign which the Aluminum Co. would give the other concerns all possible help develop- ing the proper type aluminum seat- ing. Negotiations went with number responsible firms, but their 48—THE IRON AGE, September 1940 answers invariably were the nega- tive. Rather than give the idea because these early discouragements, the Aluminum Co. decided into the manufacture aluminum furniture it- self. Sufficient room for manufactur ing operations was not available the job shop, the coupany leased plant Buffalo, Y., bought the necessary manufacturing equipment, designed line furniture, and or- ganized sales force. That was 1927. 1930 more than dollars’ worth aluminum furniture was nually. The General Fireproofing Youngstown, Ohio, leader the manufacture office furniture, soon saw the trend and added plant build- ing for the manufacture aluminum furniture. 1934 acquired the Aluminum Co.’s equipment and ex- tended its interests aluminum furni- ture. Since that time General Fire- proofing has consistently sold several million dollars’ worth aluminum furniture each year. Coincident with the development ° ° GROUP exchangers built the job shop for the tubing was expanded into tial grooves cut into header plates. furniture came that ice cube trays and grids, with result that astonished even the most optimistic. For today the use aluminum trays refriger- ators practically universal. Not all stories the job shop are success stories, however. has been known lay occasional egg. There the case the aluminum shingle, which much development work was done. The aluminum shingle, for number reasons, was impractical, and was eventually given up. Not that aluminum itself didn’t make good roof—the roof the Church St. Joachim Rome, for instance, aluminum and has been giving ex- cellent account itself for more than years—but difficulties sales, man- ufacture, and price were such that the aluminum shingle had aban- Contrast this failure with the suc- cess the aluminum beer barrel, an- other job shop development. Alumi- num barrels were new thing this country seven years ago. They de- rived their origin from the fact that the supply wooden barrels was ex- ¥ hausted after the repeal prohibition, and adequate number beer pack- ages was necessary the mushroom revival old industry. Metal barrels were demand over- night. The growth the aluminum barrel was slow first, but during the past two years this type con- tainer has become many important breweries have bought aluminum barrels the thousands. The building which housed the job shop again became too small, and 1936 new three-story building, with floor space excess 80,000 sq. ft., was erected. Steam-jacketed kettles and other large spinnings are made the first floor. The second floor de- voted general fabrication. the third floor large tanks and chemical equipment are made. The old shop reserved for the manufacture alu- minum beer barrels and seam, and resistance welding. Constant attention the problems welding brought results the job shop. 1930, for instance, was possible spot weld two sections aluminum each 0.1 in. thick. Today, the technique spot welding alumi- num has been increased the point where the maximum ness such sections 3/16 in. Jobs special interest which were made the job shop 1937 included two field-erected storage tanks, largest ever built aluminum. Each has capacity 168,000 gal.; each ft. high and ft. diameter. the same year synthetic resin kettles, high purity aluminum, were made the job shop. They were designed operate under full vacuum 600 deg. Marine applications aluminum have been interest for years. An- ticipating increase this interest, the job shop constructed three 16-ft. sailboats aluminum last year. Made from designs Starling Burgess, whose drafting boards produced the last three winners the America’s Cup, the hulls these three boats weigh only 217 Ib. mately half the weight wooden boat similar size. Their entire weight, including mast, boom, sails, rigging, gear, floor boards, and seats, less than 300 Ib. development the job shop the perfection aluminum brazing technique. Brazing aluminum was impossible few years ago, but earnest study and experimentation field has been opened aluminum fabricators from which they will with- out doubt realize tremendous advan- tages. The joining costs brazing are considerably less than those ob- tained with standard gas are weld- ing, the joints are neater and require less finishing, and the process permits joining parts that are too thin welded. The new process ex- pected mean much the alumi- num industry all types aluminum welding meant only relatively few vears ago. Such, brief, are some the many developments pioneered per- fected the job shop the Alumi- num Co. America the long period its exist