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By Morris Cohen, Robert C. Ruhl

The phases in Fe-C alloys over a wide composition range have been studied after splal quenching from the liquid state. Binary alloys containing 0 to 5.1 wt pel C as /cell as a large number of ternary Fe-C-Si alloys with 2.5 to 5.0 wt pct C and 0.3 to 5.1 wt pct Si were attlong those sludied. Olher Fe-C-X alloys, zcilh X being Co, Cr, ,Wn, Ni, and Ru , were also inrestigated after splat quenching. At high carbon contents, a new hcp phase (designaled 6 phase, but different from e carbide) is retained upon splat quenching. The .fraction of this phase varies up lo 97 pcl for a Fe-4.K-1.9% alloy. The composition of the E phase ranges from about 3.8 10 4.8 wt pet C, and the corresponding laltice parameters increase linearly ulith carbon content, while the c/a ratio remains essentially conslc~nl. The E phrtse appears to he a solulion of carbon in E iron, the latler being nornially found only at high pressures. It is deduced that the unit cell of the E phase corresponds to the formula Fe12C3, and llzal il is relaled to tlie ordered slruclures 0.f 6 iron carbide and c iron nilride. The E phase is compared and contrasted to the olher known carbides and nitrides of iron and nickel. An exlrapolaTion of the atomic volume 1,s carhon conlent of /he E pllase lzcts giz.en a neu7 estitnale jor /he alomic volume of E iron, 11.30 cu A, a1 atmospheric pressure and temperature. Other alomic volume relalionships lead to /he co~zpositioti Fe2.iC tor E iron carbide, /he unit cell fortr~ula being -Fe2rClo The E phase undergoes a lulo-slage decomposition upon healing, .forrning firsl rnarlensile plus E carhide, a/ler 1 hr at 140" lo 200°C, slid then ferr ite Plus cementile, after 1 lir a1 330" to 460°C. A1 carbo,l contents between 1.5 and 3.0 LC/ pcl, (he predo.wirzar/t plzase alley quenching is fcc austenite. The retained carbon content of this phase increases with itlcreasing silicon in certain concentration ranges, reaching a maximum of 2.37 wt pct C itz a Fe-2.6C-4.OSi alloy. This is the highest carbon conten1 reLaitled in austenite to date. These high-carbon aus-tenites can be partially tm?zsforttled lo tnartensile hy severe deformation in the temperature range of — 190 to -50°C. TECHNIQUES for splat quenching from the liquid state have been utilized in numerous recent investigations to produce metastable phases in a variety of alloy systems. Among the several ways of splat quenching, the shock-tube method appears to yield the highest cooling rates1-3, 7, 8 and was adopted here. Estimated cooling rates attained in the present experiments ranged from 10' to 10 80Cper sec.' As a part of a research program on interstitial al- loy phases, the Fe-C system was selected for splat-quenching studies. It was hoped that splat quenching would allow high metastable supersaturations of carbon to be retained in solution. Also of considerable interest were the conditions governing the occurrence of the various intermediate phases upon solidification. The alloys investigated included both binary Fe-C compositions as well as six ternary Fe-C-X alloy systems. The known phases in the Fe-C system are summarized in Table I.* Only the ferrite and graphite are ent investigation.14 and is described in detail herein Table II summarizes corresponding data on Fe-N phases, which are also of interest here because of their similarity to the Fe-C phases. EXPERIMENTAL PROCEDURES Alloys were prepared by melting the elements. 99.9 pct purity, in an inert gas nonconsumable electrode arc furnace. The buttons. weighing about 5 g. were remelted twice. were then fragmented. and their interior surfaces were examined for uniformity: if any doubt existed. they were remelted again. Chemical analyses were performed on all the alloys. the accuracy being about k0.05 wt pct. At high temperatures, carbon-containing alloys react with alumina crucibles as follows: If the atmosphere in the splat-quenching furnace does not contain sufficient carbon monoxide the alloy can be depleted of carbon and contaminated with aluminum. Calculations and experimental observations showed that 50 to 100 torr CO partial pressure effectively blocked the above reaction in all the alloys investigated. The splat-quenching equipment in Figs. 1 and 2 provides for evacuation and back-filling with CO-Ar mixtures. The furnace is capable of operation up to 1650°C. and the gettering action of the graphite heating element reduces the oxygen partial pressure in the furnace atmosphere to below 10-5 torr, thus preventing oxidation of the specimens.

Jan 1, 1970

By F. C. Noyes

DAME Nature was in a generous mood when she distributed widely over the face of the globe numerous deposits of phosphate rock from which man can make phosphatic festiIizer to replace the phosphate re- moved from the soil by crops. The principal deposits are readily accessible to the world's greatest consuming areas and most of them are such that mining operations can be carried on at relatively low cost. The world's known reserves shown in Table 1 are sufficient to last well over 2000 gears at the present rate of consumption. Before giving a brief outline of the phosphate rock industry of foreign countries let us try to get a picture of the movement of phosphate rock throughout the world in 1938, the last full normal calendar year where it came from and where it was consumed. Table 2 shows the origin and finial destination of world shipments in 1938 by grand divisions. Table 3 (p. 499) shows shipment9 of phosphte rock to each country in Europe. Europe is seen to be by far the world's greatest market and the French North African mines the world's most important producers outside of the U. S. A.

Jan 1, 1944

By H. W. Highriter

THE method developed and used in this laboratory for the production of metallic uranium of such purity that it is ductile and can be cold-worked to fine wire or thin sheet by rolling has already been described1. It consists, briefly, in the electrolysis of potassium uranous fluoride (KUF5) in a molten bath composed of equal parts of sodium and calcium chlorides. The bath is contained in a graphite crucible, electrically heated to about 775° C., the crucible serving as the anode for electrolysis. The uranium deposits in finely divided form mixed with salts upon a molybdenum cathode suspended axially in the crucible. Upon com-pletion of the electrolysis the cathode is removed and cooled, the deposit broken and leached to remove salts. The metal powder is washed with water and dilute acetic acid and dried in vacuo to reduce oxidation. Suitable amounts are then pressed into pellets and heated in vacuo by high-frequency induction, using a thoria crucible. The uranium melts and flows away from the pellet, leaving a shell, which is largely oxide. In general, this method produced a satisfactory metal, although at times the uranium was not ductile. The investigations recorded here were made to find the cause of this embrittlement. It was known that the metal generally contained carbon, derived from disintegration of the graphite crucible in which electrolysis is conducted, in amounts dependent upon the thoroughness of washing the metal powder. Accordingly, analyses of several samples, both ductile and brittle, were made by combustion and absorption of C02 in Ascarite, using air instead of oxygen to reduce the temperature and rate of oxida-tion. Several of these metals were made with special precautions to reduce carbon content. The results show no relationship between ductility and carbon content in the range investigated (Table 1).

Jan 1, 1935

By Fredrick C. Kruger

Introduction This surprisingly little-known group of minerals, the nonmetallics, so-called for their lack of metallic luster, is the largest group of the mineral kingdom, and cinstitutes perhaps 75 percent of all mineral species. For the most part, these minerals are compounds of the common acids, oxides, hydroxides, and two elements, carbon and sulfur. The list of the non- metallic minerals, therefore, is very long. It includes the borates, carbonates, chlorides, fluorides, nitrates, phosphates, silicates, sulfates, and less commonly, arsenates, chromates, molybdates, suliides, tungstates, and vanadates, the latter groups, and many of the oxides, being sought principally for their metal content. Those nonmetallics used commercially are generally called the industrial minerals, although in addition this term also includes a considerable group of rocks. The list of industrial minerals and rocks is continually growing as new uses are found, and it now numbers over 300 commodities. The industrial minerals industry has developed since about 1920. There- fore, the development has been fast, and it has been more or less parallel with the development of the art of minerals beneficiation. General Discussion of the Group This group is so heterogeneous that it has defied logical, or widely accepted, classification, whether by origin, composition, or end use, and perhaps for this reason the industrial minerals generally have received short shrift in both teaching and research. Except for those involved with asbestos, cement, fertilizers, gypsum, salt, sand and gravel, few large companies have deigned to enter the field, and consequently most industrial minerals have been developed for the most part by the small operators or entrepreneurs. Yet surprisingly, except for one war year, the nonmetallics have always surpassed the metals in value and tonnage (Fig. 1). One main characteristic that most of the nonmetallics have in common is direct sensitivity to labor and transportation. In other words they are characterized by large bulk and low-unit value, and hence have what might be termed a "place value".

Jan 1, 1971

By AIME AIME

IN view of the approaching visit to Japan and the Imperial Steel Works at Yawata by our members, the following notes on present conditions in the industry there will be of interest. The data were collected by the representatives of the Bureau of Foreign and Domestic Commerce in Japan and are furnished here through the courtesy of the Department. In connection with the proposed suspension of both new and old Government undertakings and the general depression in building, which is expected to result from the retrenchment policy of the Government, some cuts in iron and steel prices have been made by dealers. It is expected that the Yawata Steel Works may reduce its round bar prices for November delivery by 1 yen.

Jan 1, 1929

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18 23 Chattanooga, Tenn May ?78 7 3 24 Lake George, N.Y. Oct. ?78 7 25 Baltimore, Md. Feb. ?79 7 26 Pittsburgh Pa, May ?79 8 27 Montreal, Canada Sept, ?79 8 28 New York, N.Y. Feb, ?80 9 29 Lake Superior, Mich Aug, ?80 9 30 Philadelphia, Pa. Feb, 81 9 31 Staunton, Va May, 81 10

Jan 1, 1923

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18 23 Chattanooga, Tenn May ?78 7 3 24 Lake George, N.Y. Oct. ?78 7 25 Baltimore, Md. Feb. ?79 7 26 Pittsburgh Pa, May ?79 8 27 Montreal, Canada Sept, ?79 8 28 New York, N.Y. Feb, ?80 9 29 Lake Superior, Mich Aug, ?80

Jan 1, 1923

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18 23 Chattanooga, Tenn May ?78 7 3 24 Lake George, N.Y. Oct. ?78 7 25 Baltimore, Md. Feb. ?79 7 26 Pittsburgh Pa, May ?79 8 27 Montreal, Canada Sept, ?79 8 28 New York, N.Y. Feb, ?80 9 29 Lake Superior, Mich Aug, ?80 9 30 Philadelphia, Pa. Feb, 81 9

Jan 1, 1923

By S. R. Dunbas, D. C. Jillson, E. A. Anderson

THE present work was undertaken to furnish information, lacking in the literature, on the deformation mechanisms active in pure titanium at room temperature. Since it was started, Rosi, Dube, and Alexander' have indicated that slip can occur in coarse-grained (2 to 6 mm diameter) titanium on the {1010} and {1011} planes and twinning can take place on the {1072}, (1122) and (1151) planes. Liu and Steinberg,' working with titanium flakes produced by fused salt electrolysis, found evidence of twinning on the {1032$, {1121), {1122}, (1123}, and (1154) planes. The crystals used in the present work were substantially longer (up to nearly 2 in. in length) and possibly purer. Production of Large Crystals It was the purpose of this part of the work to provide single crystal or large grain specimens for use in the deformation studies rather than to study the mechanism of crystal growth. Accordingly, all further exploratory studies on methods were abandoned when it was found that cold-rolled bars sealed in vacuo in individual Vycor tubes and given three or more cycles of 4 hr at 1200°C and three to five days at 850°C, gave large grains. Eighteen specimens about 0.2 in. square x 2 in. long yielded 33 useful grains, ranging from Va in. to nearly 2 in. in length, with an agreeably wide range of orientations, Fig. l. The 0.25 in. thick strip from which the starting specimens were cut had been reduced 67 pct on 18 in. diameter rolls from a scalped, hot-forged (959" to 1000°C), arc-melted, iodide titanium ingot. Thc bar was at room temperature, but the rolls were at 200°C. Reductions of about 0.03 in. per pass were used. The bar was cut into four segments, each of which was rolled in a somewhat different manner. No effect on the growth of large grains was noted. The composition of the titanium, determined on turnings from the ingot scalping operations, is given in Table I. The Rockwell A hardness of the ingot was 26. The standard starting specimens, about 1/4x1/4x2 in., were milled on all four sides, hand polished on 280 and 400 mesh emery papers, etched for 3 min in a 50 HF-50 glycerine solution, rinsed, and dried in alcohol and ether just before sealing them in Vycor tubes. The average specimen weight was 7.5 g, and the tube volume was 6.5 cc. A vacuum of less than 1 micron pressure was applied. The specimen tubes were placed in an evacuated Inconel muffle to minimize the danger of collapse of the glass tubes at temperature. In practice the specimens were first heated to 1200 °C for 4 hr and then transferred fairly quickly to an 850°C furnace where they were held for three to five days. This cycle was repeated at least three times before the specimens were cooled, removed from the tubes, lightly polished and etched on one surface for examinstion. Those in which large grains had not developed were resealed in Vycor and returned to the cycling. Satisfactory specimens (about one out of every four cycled) were polished with emery paper on all four side;, then metallographically polished using ctchinz between wheels to remove distorted metal and, finally, given a very light etch to reveal the grain boundaries. This was necessary because the surface was roughened by the sublimation of titanium under high temperature vacuum conditions. Specimens were identified by TiXl numbers using supplementary letters to designate specific grains.

Jan 1, 1954

A comprehensive, systematically structured mineral evaluation system is a prime requirement for objectively assessing mineral supply impacts on the economy. The Minerals Availability System developed by the US Bureau of Mines is a step in the right direction-a well-organized unraveling of the mineral supply network, structured in format to allow quick retrieval for rapid listing, supply analysis, and other uses.

Jan 9, 1977

By M. R. Geer

Coal washing assumed an important role in the mining industry of the Pacific Northwest long before washing practice became firmly established in the Appalachian field. A Scaife washer was operated in the state of Washington in 1887; and by 1927, the fist year for which complete statistics were compiled, nearly a third of the state's coal production was washed, in comparison with only about 5 pct for the country as a whole. Mechanical preparation was adopted in Alaska in 1922 in a plant constructed by the United States Navy at Chickaloon to provide bunker coal for naval forces operating in northern waters. Many of the coal beds mined in Washington and Alaska contained more impurities than those mined elsewhere, and this circumstance contributed to the early interest in mechanical cleaning. A much more important factor, however, was the inclination of the coal beds. With steeply pitching beds, hand sorting by the miner at the face is impossible; consequently, all material must be loaded and dealt with on the surface, just as is now proving the case with mechanical mining of flat beds. Thus "full-seam" mining afforded the same stimulus to the early development of coal washing in the Northwest that - it is providing under mechanization in the rest of the country today.

Jan 1, 1949

By L. D. Jaffe, D. C. Buffum

EARLY papers1-' reported that temper brittleness is influenced by microstructure. This conclusion was based on room temperature impact tests, the inadequacy of which has been pointed out. Pellini and Queneau7 measured impact energy absorption at —80O to +25oC for several microstructures. On the basis of the shift, associated with temper brittleness, in the energy vs testing temperature curve they concluded that tempered martensite is somewhat more susceptible to temper brittleness than is tempered pearlite. The range of temperatures was insufficient to give complete curves covering the transition from tough to brittle behavior, so it is difficult to evaluate quantitatively the shift for the different microstructures. Also, the smaller shift of pearlite might be attributed to its already being temper embrittled at its temperature of formation. Accordingly, blanks 2 3/16 in. long were cut from a heat of SAE 3140 hot rolled steel barstock, 5/8 in. diameter, on which other work has been reported? A set of blanks was austenitized 1 hr at 900°c, water-quenched, tempered 16 hr at 675oC, and water-quenched, giving a microstructure of 100 pct

Jan 1, 1954

By N. S. Wagner

The production of lightweight aggregates in Oregon is a new industry, and, like all new enterprises, it is suffering from growing pains characterized by numerous, small operations some of which flourish for a short time and then cease altogether. Normally all industrial mineral products are produced in a highly competitive atmosphere. At the present time this condition does not exist to a very marked degree in the state because as yet producers have not saturated the constantly expanding market. This paper has been prepared with the intention of outlining very briefly the current status of the various products now being used as lightweight aggregates in Oregon. The present picture will surely change, perhaps quite radically within even a short space of time.

Jan 1, 1949

By Robert S. Baker

It has been demonstrated in the laboratory by A. J. Phillips1 that a transformation or conversion from beta directly to alpha may take place in a brass of 61 to 62.5 per cent copper content. The completion of the transformiation is dependent on a rapid rate of cooling from the all-beta field through the alpha + beta range to the alpha field. Phillips states that in a slowly cooled alloy containing 62 per cent copper and 38 per cent zinc the copper content of the beta is progressively decreased from 62 to 56 per cent by precipitation of alpha. Rapid cooling tends to prevent the separation of alpha with a copper content of more than 62 per cent by reducing to a minimum the time required for passing through the alpha + beta range. Upon crossing beyond the (alpha + beta) (alpha) boundary to the all-alpha region below, the material is transformed from beta to alpha. It, is essential that there be no change in composition. Phillips obtained his results by quenching a 62:38 copper-zinc alloy from 850" C. in iced brine at -8" C. No reference to the occurrence of this transformation in a manufacturing process has been found in the literature. An investigation of the microstructures of a number of hot forgings made from leaded brass rods yielded one forging in which this striking conversion from beta to alpha had occurred. The purpose of this paper is to describe the transformation and certain conditions under which it may occur during the hot pressing of brass. The conversion was noted in a shape forged from a leaded brass rod, the composition of which was: Cu, 60.26 per cent; Zn, 37.86; Pb, 1.88. In this study the lead content was disregarded and the alloy was considered to be equivalent to an alloy of 61.40 per cent copper and 35.60 per cent zinc (9812 parts = 100 parts). The possibility that the lead might obstruct or accelerate the precipitation of alpha was not studied. The lead appears as black globules in the photomicrographs and has a negligible solubility in the alloy.

Jan 1, 1932

By Daniel Bloomfield

ONE of the major problems of management is how to restore in some measure the personal relation-ship between employer and employed which, in the days of small concerns, meant better morale among employees. The complexity of industry today, the heterogeneous mass. of workers employed, many .of them new to this country and to its institutions, the inability of those whose task it is to get out production to spend much time on the problems of labor-all these and many other factors serve to make of great impor-tance the question of how to establish more satisfactory mutual good will. While there is no such thing as a sure cure for labor troubles, in spite of the fact that charlatans have been selling alleged cures to guileless employers, study and experience have brought to light methods of approach to the problems confronting management in its relation to labor that are well worth consideration. Labor problems must be approached with common sense and an open mind. Facts must be the basis of action. So it is with the question of morale in industry. What makes or breaks morale? What are the forces behind the actions of men? What is there in one man that makes him act differently from another man under similar circumstances? How are men affected by the actions of others in their own group or by the actions of those under whose supervision they work? These are questions that must be carefully studied if we are, to get at the bottom of industrial unrest. It is an easy thing to say that good will can be created by "treating men right." That involves so many things and points of view that it will hardly serve as a full answer to our problem; but it is a good starting point if we mean by right treatment the payment of wages consistent with the well being of the worker and his family as members of the community, and if we also mean the provision of sanitary, wholesome working conditions and a working schedule that does not overtax the worker physically, and mutuality-a give and take relationship. With this as a basis we can go a step farther and see what else can be done to promote better relations between management and the workers.

Jan 9, 1922

By Charles Wurms, Robert Steinitz

DURING an investigation to determine the compatibility of several metals with tungsten, the degree of reaction between tungsten and lead was determined. A literature survey showed considerable disagreement between the results of various earlier investigators. Information presented by M. Hansen1 states that, according to S. Inouye,2 tungsten has very poor resistance against attack by molten lead, even at the low temperature near the melting point of lead. A phase diagram in the same reference indicates a solubility of 30 wt pct W in molten lead at 1300°C. Contrary evidence was shown by Parkman and shepard3 in their investigation of materials for use in heat transfer systems containing liquid lead alloys; they performed experiments at 980°C for times up to 50 hr without noticing any appreciable attack on the tungsten. Tungsten sheet was immersed in molten lead contained in Vycor tubes evacuated to at least 10-4 mm Hg. R. Bernard4 and R. I. Jaffee5 also indicate that no reaction occurs between molten lead and tungsten. However, no experimental data were included in these reports. In order to settle the question of the solubility of tungsten in molten lead, tungsten powder with an average Fisher subsieve particle size of 6µ was pressed in a double-acting die at 6 tsi to small compacts. They were then sintered in an atmosphere of hydrogen for 2 hr at 1700°C, resulting in a sintered density of 64 pct of theoretical with final dimensions of 0.260 in. in height and 0.245 in. in diameter. For all tests, the tungsten pellets were immersed in molten lead. Table I is a summary of the experimental procedures showing atmospheres, temperatures, and times. The first experiments were performed at 650°C; at this temperature, the liquid lead should wet the porous tungsten better than at its melting point, and penetrate into the pores. The lead was heated in a graphite crucible with a graphite cover. No protective atmosphere was used, as it was expected that the formation of CO would be sufficient to prevent oxidation. This, however, proved to be wrong, and all tungsten samples showed a slight oxide film after treatment. The tungsten samples were immersed in the molten lead for times of 5 min, 10 min, 1/2 hr, 1 hr, and 2 hr. After this time, the melt was poured into a form and the

Jan 1, 1962

By H. O. Hofman

THE leading antimony mineral is stibnite. In smelting stibnite ore two processes are available, precipitation and roasting-reduction. The former is suited only for high-grade ores. As low-grade ores are more common than high-grade, roasting-reduction is of greater importance than precipitation. In the roasting process the aim may be to leave the oxidized antimony in the ore, or it may be to volatilize as much of the antimony as possible, collect the volatilized oxide as a rich intermediary product and smelt it for antimony, leaving the gangue poor enough to be considered a waste product. Whichever way the roast is conducted certain difficulties inherent in stibnite are encountered. These are: 1. The low melting point of stibnite which; according to Pelabon,1 is 550°C., according to Wagemann2 540°C., and according to Borgström3 546°C. 2. The ignition temperature: According to Friedrich,4 stibnite, if heated in air, begins to oxidize at 290°C. if the size of a grain is 0.1 mm. in diameter; at 343°, if 0.1 to 0.2 mm.; and 430° if 0.2 mm. 3. The fusibility of a mixture of Sb2S3 and Sb203 which in the form of kermesite (Sb2S3)2.Sb203 melts at 517°C.5 4. The volatility of Sb2S3 and Sb203, for which no numerical data appear to exist, although practical experience has shown that they are volatile at low temperatures.

Jan 1, 1916

By N. Parlee, V. C. Kashyap

The solubilities of nitrogen in liquid iron and liquid Fe-Ni, Fe-Mo, Fe-V, and Fe-Mo-V alloys were measured by the Sieverts method. Measurements were made at 1600° to 1800°C on binary alloys up to 20 pet Ni, 10 pet V, 10 pet Mo; and on ternary alloys containing 0 to 3 pet V with 0 to 5 pet Mo. The results on liquid iron confirm that Sieverts' law is obeyed in the range 50 to 750 mm pressure. The measured solubilities and their temperature coefficients are in general agreement with other modern authors. The logarithms of the activity coefficients of nitrogen in the binaries are approximately linear functions of the pet of alloying element. A method suggested by Wagner, Chipman, and others for predicting gas solubilities in complex alloys from solubility data on binaries was applied to the Fe-Mo-V alloys. Reasonably good agreement was obtained between calculated and experimental solubilities. NITROGEN'S solubility in liquid iron has been studied by a number of investigators. It is reasonably well established that the solubility of nitrogen follows Sieverts' law at least up to 1 atm partial pressure and that the solubility increases gradually with temperature. The solubility of nitrogen in Fe-X binary liquid systems has been investigated in only a few cases. Only the systems Fe-Cr,3-5, 7 Fe-V,3 Fe-Mn,3, 5 Fe-Ni,3, 5 Fe-Si,B, H Fe-C, L, H and Fe-P4 appear to have received any study. The only work on liquid Fe-V was done by Brick and Creevy.3 This was limited to 13.5 pet and 26.5 pet V, but no exact temperatures were recorded. No work whatsoever appears to have been done on liquid Fe-Mo alloys and even work on Fe-Ni alloys is rather scant. The work on liquid ternary systems is still more limited, and the only publication available appears to be that of Wentrup and Reif,7 who studied the Fe-Cr-Mn and Fe-Cr-Ni alloys. Rassbach, Saunders, and Harbrecht17 have reported work on the solubility of nitrogen in stainless steel but this was not a systematic study of any particular system. Commercial alloys usually contain several alloying elements. Thus, it often becomes important to be able to predict the nitrogen solubility in systems containing two or more added elements without the necessity of making measurements. Wagner,14 Chipman," Darken and Gurry," and Morris and Buehl 14 have suggested means by which this may be accomplished, and Langenberg14 has recently applied one of these methods to nitrogen solubility in complex liquid alloys. This paper reports the results of nitrogen solubility determinations on Fe-Ni, Fe-Mo, Fe-V, and Fe-Mo-V alloys and compares calculated and experimental solubilities in the ternary alloy. Attempted measurements on Fe-Cr alloys were not successful by the experimental method employed. Experimental Method The general method of solubility measurement was that of Sieverts.' The apparatus and procedure were essentially the same as used by Liang, Bever, and Floe."' The equipment consisted of a small vacuum furnace heated by a 6 kw induction unit, gas measuring apparatus, and a gas purification train. The crucibles used were Norton Alundum with alumina sand around them for insulation. The crucibles were charged with 100 to 200 g of material, about 180 g or nearly filling the crucible being found most satisfactory. Hot volumes were determined with argon and ranged from 95 to 130 cu cm (stp). Temperature measurements were made with a Leeds and Northrup optical pyrometer which was calibrated periodically against the melting point of iron in the same apparatus."-'* Good quality nitrogen, hydrogen, and argon gases were further purified and dried in standard purification trains. The sources of the high purity iron and other alloying elements used were as follows:

Jan 1, 1959

By Lane, K. S.

The problem of stability of slopes in reservoirs is one of real interest in civil engineering. The problem is whether the valley walls will remain stable or whether they are likely to slide as conditions are changed by storage of water in the reservoir. If major slides are indicated, as on the walls of relatively steep canyons, one must estimate whether they will be so located and of sufficient size as to interfere with operation of the reservoir-as by blocking the outlets, or by displacing sufficient water to over-top the dam in a huge wave. Some cases involve problems in soil mechanics for slides in earth or weaker rock; other locations need the assistance of rock mechanics for slides in harder rock. While this is not a new problem, attention has recently been focused on its importance by the hugh landslide into the Vaiont reservoir in 1963, which claimed the lives of over 2000 people and forced abandonment of the dam and powerhouse.

Jan 1, 1969

By L. C. Chang, T. A. Read

Diffusionless transformation in Au-Cd single crystals containing about 50 atomic pet Cd was investigated by means of X-ray analysis of the orientation relationships, electrical resistivity measurements, and motion picture studies of the movement of boundaries between the new and old phases during transformation. The nucleation of diffusionless transformation by imperfections and the generation of imperfections by diffusionless transformation were discussed. THAT connections exist between plastic deformation and diffusionless phase changes has long been recognized. Thus it is often possible to produce a diffusionless phase change in a temperature range, above that in which the change occurs spontaneously, by cold-working the initial phase. Certain aspects of the dislocation theory of the plastic deformation of crystalline solids also provide for a rather direct connection between the processes involved in plastic deformation and in diffusionless phase changes. Heidenreich and Shockleyl have pointed out that simple edge dislocations in f.c.c. metals are probably unstable, and that the more probable lattice imperfections, called extended edge dislocations, consist of two half dislocations separated by a distance of the order of magnitude of 100A. The region about two atomic planes thick between the half dislocations because of this stacking fault may be described as having the hexagonal close-packed structure. Presumably the stacking faults observed by Barrett" fter cold-working f.c.c. Cu-Si alloys resulted from the passage of such half dislocations through the lattice of the initial phase. It is now becoming clear that the development of a detailed theory of the atomic movements involved in diffusionless phase changes will require a consideration of the role played by lattice imperfections, just as such considerations are necessary to the understanding of plastic deformation mechanisms. This point of view has been recently set forth, for example, by Cohen, Machlin, and Paranjpe3 who pointed out the role which might be played by screw dislocations in nucleating diffusionless phase changes. The present paper reports on some aspects of the diffusionless phase change in single crystals of the beta phase alloy Au-Cd which serve to emphasize further the importance of lattice imperfections in diffusionless phase changes. The diffusionless phase change of Au-Cd possesses several remarkable features. One of these is that the interface between the high-temperature beta phase and the low-temperature orthorhombic phase typically moves with a low velocity, in contrast to the behavior observed in the transformation of austenite to martensite. Motion pictures of this slow interface motion have been prepared in the course of the work reported here. Another important feature of the Au-Cd transformation is the small amount of undercooling observed. The reverse transformation occurs on reheating to a temperature only 20" higher than the transformation temperature observed on cooling, and under some circumstances the hysteresis observed is substantially less than this. This narrow temperature range between transformation on heating and cooling is presumably in part a consequence of the fact that the transformation requires a lattice shear of only about 3". Finally, the orthorhombic product phase possesses unusual mechanical properties, as was first pointed out by olander' and Benedicks." After completion of the transformation on cooling the specimen can be severely deformed, yet on the release of load it springs back to its original shape in a rubber-like manner. Explanation of this phenomenon will require an understanding of the lattice imperfections in the orthorhombic structure and, correspondingly, of those in the initial body-centered cubic structure. Single crystals of Au-Cd alloy containing 47.5 and 49.0 atomic pct Cd were prepared from fine gold (99.95 pct purity) and chemically pure cadmium (99.99 pct purity) by melting the alloy in an evacuated and sealed fused quartz tubing and growing into single-crystal form by the Bridgman method. The Au-Cd alloy containing 47.5 atomic pct Cd undergoes a diffusionless transformation from an ordered body-centered cubic structure to an orthorhombic structure when it is cooled to about 60°C, while the reverse transformation takes place when the alloy is heated to about 80°C, according to electrical resistivity studies. The structures of these two phases have been studied by Blander,4 reinvestigated by Bystrom and Almin.e he lines of Debye photo-gram of powdered samples of Au-Cd alloy containing 47.5 atomic pct Cd prepared in this laboratory were identified and agreed fairly well with those of

Jan 1, 1952