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By William D. Southard, Joseph W. Schlitt, Bruce P. Ream, Lawrence J. Haug

The operation of Kennecott 's Bingham Canyon copper precipitation plant, one of the world's largest, is described. This description includes a brief historical review of precipitation at Bingham and the general layout and operation of the present cone cementation facility. Current practices are based on results of studies undertaken to define improvements needed in each unit operation. These improvements were required to meet changing plant conditions and were implemented primarily within the constraints of the existing facilities. Specific unit operations included were the cone precipitators, the cone discharge thickener, the cone effluent settling basins, and the plate and frame filter presses. As a result of these improvements, loss of precipitated copper decreased and the degree of precipitation increased, raising copper recovery by 9 t/d. At the same time, iron consumption was reduced by 22.5 t/d. Problems in drying the cement copper were also overcome so that a product containing 12-15% moisture could be consistently delivered for smelting.

Jan 1, 1980

By W. Joseph Schlitt, William D. Southard, Bruce P. Ream, Lawrence J. Haug

The operation of Kennecott's Bingham Canyon copper precipitation plant, one of the world's largest, is described. This description includes a brief historical review of precipitation at Bingham and the general layout and operation of the present cone cementation facility. Current practices are based on results of studies undertaken to define improvements needed in each unit operation. These improvements were required to meet changing plant conditions and were implemented primarily within the constraints of the existing facilities. Specific unit operations included were the cone precipitators, the cone discharge thickener, the cone effluent settling basins, and the plate and frame filter presses. As a result of these improvements, loss of precipitated copper decreased and the degree of precipitation increased, raising copper recovery by 9 t/d. At the same time, iron consumption was reduced by 22.5 t/d. Problems in drying the cement copper were also overcome so that a product containing 12 - 15% moisture could be consistently delivered for smelting.

Jan 6, 1979

By E. P. Chartkoff, W. P. Sykes

In 1926 one of the authors published researches on the determination and description of the iron-tungsten and iron-molybdenum systems,' including the equilibrium diagrams. In 1929, further work was carried on, including the examination by X-rays, which is recorded here. Meas-urements were made of changes in lattice parameters in the solid solutions. Precipitation from the solid solution and the accompanying changes in hardness were studied as well as the formation of the intermetallic com-pound phases upon sintering a mixture of metal powders. Materials All the specimens were prepared from the same quality of metals and by the same methods as were described in the determination of the constitutional diagrams. The metal powders as mixed and pressed were sintered or fused in a hydrogen atmosphere and subsequently treated as indicated in the titles of the figures. The formation of the iron-rich solutlon in the solid was accomplished by sintering in hydrogen for a period of 20 to 30 hr. at a temperature 25' to 50' C. below the melting point of the eutectic. The tungsten-rich and molybdenum-rich solid solutions of iron were prepared by adding the iron as a solution of iron ammonium oxalate to the oxide of tungsten or molybdenum, followed by a hydrogen reduction. This method results in a homogeneous alloy after sintering the pressed metal powder for 20 to 30 hr. at a temperature slightly below that of the peritectic reaction in the system involved. For X-ray examination the specimens were variously prepared, depending on the nature of the sample and what it was desired to show. For example, the iron containing tungsten or molybdenum in solid solution was cut with a file, the chips were put through bolting cloth, and this powder of filings formed the specimens for comparative study. The

Jan 1, 1930

By D. Turnbull, J. H. Hollomon, J. C. Fisher

UNDERSTANDING of the diffusion problem has recently been furthered by the analysis of Birchenall and Mehl.1 They pursued the problem of the variation of the diffusion coefficient with composition for non-ideal solid solutions. Their analysis follows the tradition of Wagner,2 Jost,3 Dehlinger,4 and Darken,' who assumed the net flux of dif¬fusing material to be proportional to the gradient of a quantity related to free energy. The basic assumption in Birchenall and Mehl's formulation of the problem is that the net flux of diffusing material is proportional to a thermodynamic activity gradient. To estimate the applicability of the derived relations, they corrected the diffusion coefficients of carbon in austenite by utilizing Smith's' activity data for carbon, and the diffusion coefficients for zinc in copper with activity data computed from the vapor pressure measurements of Hargreaves.7 The corrected coefficients for carbon were virtually independent of carbon concentration. For the diffusion of zinc in copper a moderate variation of diffusion coefficient with concentration remained after the correction. The problem of diffusion can be formulated in another way than that used by Birchenall and Mehl. The method is that of chemical rate theory and has been used by Eyring and his coworkers8,9 as well as by Eyring and Zwolinski10 in a discussion to Birchenall and Mehl's paper. As yet the method has not been applied to substitutional solid solutions. On the basis of their assumptions, Eyring and Zwolinski derived a relation between the diffusion coefficient and activity that is identical with that of Dehlinger and Darken but which does not correct for the variation of the diffusion coefficient with concentration as well as does the relation derived by Birchenall and Mehl. It was thought that the theory of diffusion would be more complete if the inconsistency between the two analyses could be rationalized and if diffusion in substitutional alloys were analyzed on the basis of the concepts of the chemical rate theory. CHEMICAL RATE THEORY According to the theory of absolute reaction rates8 the reaction [A,+A2+ ... +.A;->X,+X2 +...+X; EqI] is viewed as taking place in two steps. First the reactants A1, A2, . . . A[i] combine to form an activated complex M with which they are in equilibrium; [A, + A2 + .. . + Ai = M. Eq 2] Second the activated complex decomposes to give the products X1, X2. . .. X[j]; [M->X1+X2+ ... +.X;. Eq3] It has been shown8 that the number of activated complexes decomposing per unit volume per unit time is given by the expression† [kT]

Jan 1, 1948

By G. B. Sazuyer

DEVELOPMENTS respecting beryllium during the past year have been sufficient to center attention on it as likely to be the most important of any of the chemical elements that have recently found a place for themselves in technical industry. This importance is only potential, however, largely because adequate supplies of beryllium ore will be necessary. The beryllium industry will be only as great as the mines which support it. To find and develop large mines will be the problem. Chief of the immediate commercial developments in the United States is beryllium-copper and its espousal by Anaconda and Riverside even at present high prices. According to the pamphlets of these companies, it ap¬pears that beryllium is to copper nearly what carbon is to iron. When one considers that the tensile strength of pure copper is about 33,000 lb. per sq. in., but that the addition of 1.5 to 2.5 per cent of beryllium produces a heat-treatable alloy with a maximum tensile strength of 220,000 lb. or over, the analogy to carbon and iron is made strikingly, clear. Striking among the properties of beryllium-copper is its resistance to fatigue, claimed to be equal or superior to that of spring steel. It needs little imagination to foresee a great industry for this alloy alone.

Jan 1, 1934

By R. K. Ham, M. L. Wayman

TD-Nickel has been broken in tension and in fatigue at voom temperature. Rod specimens failed in tension by necking, with axial cracks attributed to voids elongated in the extrusion direction. Fatigue specimens failed in shear. Thin-film electron microscopy showed that the subgrain structure of TD-Nickel was very stable, and that particle-matrix detachment was very difficult, in tension and fatigue. TD-Nickel softened slightly during fatigue but had a high fatigue ratio (0.5at 10' cycles). Fractography suggested that Stage I fatigue crack propagation is greatly extended in TD-Nickel. Td-NICKEL* is a dispersion of 2 pct by volume of thoria (ThO2) in nickel, produced by powder-metallurgical methods including compaction, sintering, and extrusion. The spherical thoria particles, which may have a mean diameter of a few hundred angstroms, are dispersed with a mean planar spacing of a few thousand angstroms. By a combination of cold working and annealing, a subgrain or cell structure of dislocations intimately associated with the dispersion can be produced.' This gives the material useful tensile properties which are extremely resistant to exposure to high temperatures.'-= At the same time, the material shows considerable ductility.3'4 At the beginning of the present work, it was considered of great interest to investigate the mechanical stability of TD-Nickel under conditions of fatigue. On the one hand, materials which derive strength from a cold-worked structure are unstable in that they are susceptible to fatigue softening: in addition, the presence of discontinuities such as the particle-matrix interfaces might be expected to assist in the initiation and propagation of fatigue cracks, in that they may provide local concentrations of internal stress and sites for the initiation of voids." On the other hand, the substantial ductility of TD-Nickel suggests that if it obeys Coffin's relation8 (or the more refined form proposed by Manson9) it should have good fatigue resistance. The initial purpose of this investigation was to assess the importance of these factors. Also, relatively little fundamental work has been done on the mechanism of fatigue in dispersion-strengthened materials. Work on overaged A1-4 pct CU10-12 revealed a very large Bauschinger effect indicative of internal stresses at the particles, and very great fatigue hardening1' presumably due to the multiple slip stimulated by these internal stresses, followed by softening which was initially due to softening in the matrix, but later might have arisen from cracking at the particle-matrix interfaces. The study of overaged Al-4 pct Cu could not settle this latter point by the electron microscopy of thin films, since the dispersion is too coarse. A previous study of the fatigue of internally oxidized copper13 was complicated by inter granular failure, attributed to oxide particles at grain bouhdaries; internal oxidation of single crystals, however, improved their fatigue properties.'3 Investigations of SAP (sintered aluminum powder) are complicated by the complex particle shapes, and the possibility of continuous internal oxide films.14 It was hoped to avoid these difficulties with TD-Nickel, which had the further advantages that it was commercially available and suitable for study by the thin-film technique. 1) MATERIALS AND EXPERIMENTAL PROCEDURE TD-Nickel was purchased from the Driver-Harris Co. as 3/9-in.-diam rod which had been extruded, swaged, and "stress-relieved" (normally at 1010°C for 1 hr). Continuous-radius fatigue specimens with a minimum diameter of -0.1 in. were ground to shape and electropolished in 40 pct phosphoric, 35 pct sul-furic, 25 pct water at 25oC, with a stainless-steel cathode, at -6 v. Fatigue tests were carried out at room temperature with a Sonntag SF-1-U machine operating in push-pull at 1800 cycles per min, and in an Instron TT-C-L modified for reversed stressing at 26 cycles per min as described elsewhere.10 Round tensile specimens were ground with 0.85-in. gage lengths of 0.135 in, diam, electropolished, and tested in a Tinius Olsen hydraulic machine. The surfaces of fatigue specimens were examined with a Reichert metallograph. Discs for electron microscopy with a Siemens Elmiskop I were spark-cut 0.01 in. thick with a modified Servomet 11 employing a tool of moving molybdenum wire, cleaned in 50 pct acetic, 30 pct nitric, 10 pct phosphoric, and 10pctsul-furic at 85oC, and thinned by the window method in the electropolishing solution at -20°C and -6 v. Two-stage replicas (parlodion, then Pt-50 pct C self-shadowed at 40 deg) were taken from fatigue fracture surfaces for electron microscopy. Plane sections parallel to the specimen axis and containing the direction of fatigue crack propagation were polished, etched with Carapella's reagent, and examined optically. Transmission Laue X-ray photographs of as-received material electropolished to a point were used to determine preferred orientation. 2) RESULTS 2.1) The Structure of As-Received Material. Grains -1 µ diam and elongated 20 to 30 u in the direction of the rod axis were observed, With' elongated "intergran-ular" voids (-4 p diam and -90 µ long and identified as such using longitudinal and transverse sections and

Jan 1, 1968

By E. N. Harshman

Uranium mining and milling are rather new industries in Wyoming and South Dakota, but, in the past 15 years, ore valued at more than $400,000,000 has been mined and milled in the region. The major uranium deposits are in structural and/ or erosional basins or on the flanks of uplifts. The principal host rocks are medium- to coarse-grained sandstones that were deposited in continental or brackish-water environments and were derived in large part from the granitic cores of the uplifts and the sedimentary rocks that flank the cores. The ages of the host rocks range from Cretaceous to Miocene, but more than 95 per cent of the known reserves in the region are in rocks of early Eocene age. The bulk of the ore in the region is unoxidized and lies below the water table; some oxidized ore has been mined in the Powder River Basin and Black Hills districts. The unoxidized ore comprises pyrite, uraninite and/ or coffinite, marcasite, hematite, jordisite(?), and selenium. Minerals in the oxidized ore include hydrous uranium carbonates, phosphates, and sulfates and hydrous uranium and/ or vanadium silicates. The deposits are in the form of ore rolls that contain from a few hundred to a few hundred thousand tons of ore, ranging in grade from 0.1 per cent to 1.0 per cent U3O8. The rolls are at the margins of large tabular bodies of sandstone that has been altered by the orebearing solutions. The deposits are believed to have resulted from the interaction of an alkaline; oxidizing, ore-bearing ground water and a reducing environment. Exploration guides include the spatial relations of ore to altered sandstone, favorable lithology in the host rock, the content of certain elements and/ or compounds in ground water, and the relation of deposits to major paleodrainages.

Jan 1, 1968

By A. C. Fraker, H. H. Stadelmaier

In the systems Mo-Fe-C, Mo-Co-C, and Mo-Ni-C the phase boumdaries of the cubic Ij carbides were determined at 1000°C and the variation of the lattice parameter with composition was measured. In the system Mo-Fe-C a single ternary carbide, Mo3Fe3C, was observed. In Mo-Co-C and Mo-Ni-C two new n phases of the type M12C were found: Mo6C06C and Mo6Ni6C. At 1000°C they coexist with the M6C phases MO3-4,CO3-2C and Mo3-4Ni3-2C, respectively. Mo3C03C and Mo4C02C are not separate phases but parts of a single M6C phase region, and the same is true of Mo3Ni3C and Mo4Ni2C. THE n carbide structure type has been known since it was determined by westgren' in 1933, yet reliable information on phase compositions of this type is ap-parently scarce. The following selection of suggested formulas illustrates the extent of the confusion con-cerning compositions: W2-3Fe4-3C,1W6Fe6C,2 W2_4Fe4-2C,3 (W,Fe)6C,4 Tj.-W4Co2C and nz-W6Co6C,5 n1-W3Co3C and n2-w4Co2C,5 W3C03C and w6Co3C2,7 MO3Fe3C,8n2-M04Fe2C,9 (MO,Fe)6C,4 MO3CO3C,8 n2-MO4CO2C.9 Many of these compositions obviously overlap, some disagree in carbon content. The use of the designations 77, and n2 is not consistent. There is uncertainty whether two carbides M6C coexist or whether there is only one M6C with a wide range of substitution of one metal for the other. The existence of M12C seems questionable altogether if one ignores the results of a neutron diffraction study of W6Fe6C supporting that particular metal to carbon ratio.'' More reliable information is available for the iso-typic oxides studied by Nevitt,11 Nevitt, Downey, and orris," and Meussner and carpenter.l3 That n car-bides and oxides are structurally identical, particularly with respect to the location of the metalloid atom, has been demonstrated clearly by Stadelmaier and Meussner14 and also by Parthe, Jeitschko, and sadagopan.15 Therefore the present paper, which attempts to establish the phase boundaries of n defini-tively for three carbon systems, has implications for the whole family of filled Ti2Ni types. EXPERIMENTAL PROCEDURE The samples were prepared in two stages. Pellets weighing 3 g were compacted from powders of the elements and presintered in a closed tube of fused silica that had been evacuated to lO-4 mm Hg. This was fol- lowed by arc melting the sintered samples under argon. Remelting the button once was sufficient to produce homogeneous specimens. The metal powders had the following minimum purities in wt pct: molybdenum 99.5, iron 99.0, cobalt 99.7, nickel 99.9, graphite 99.94. Carbon determinations by the gas volumetric method were obtained from thirty-one of the one hundred samples in the annealed condition. They were limited to compositions that were critical to placing a boundary line in the isothermal sections. The carbon losses were comparatively low and averaged less than 1.5 at. pct. For annealing, the samples were sealed in tubes of fused silica evacuated to 10-4 mm Hg. The annealing schedule was 20 hr at 1250°C followed by 150 hr at 1000" ±10°C. For the water quench the silica glass tubes were broken mechanically to speed the quench. The specimens were examined in the as-cast and annealed condition by standard metallographic techniques. Some of the as-cast and all annealed samples were studied by X-ray diffraction using a 114.6-mm powder camera with filtered Co radiation. The lattice parameters of the n phases were determined by graphic extrapolation to 8 = 90 deg on a plot against sin2 8. It is estimated that the maximum error in the lattice parameters is ±0.002A.. The phase fields were determined by the disappearing phase method, relying on X-rays for phase identification and on microscopy to detect small amounts of a phase. RESULTS Pertinent information on the binary side diagrams has been summarized by Hansen and Anderko16 and Elliott17 and will not be discussed further. Photomicrographs documenting the equilibria at 1000°C have been selected to avoid redundancy due to the similarity of the three systems. Thus there will be only one picture showing an equilibrium with Mo2C, and so forth. Molybdenum-Iron-Carbon. An isothermal section of most of the Mo-Fe-C system at 1000°C is shown in Fig. 1. No attempt has been made to distinguish between a and y iron or to determine their phase boundaries. A conspicuous absence is the phase Fe2 1Mo2C6 with the Cr23C6 structure, supporting the suggestion by Krainer4 that it decomposes by annealing at high temperatures. The only ternary phase is found in a narrow range around Mo3Fe3C (MO43Fe43C14). A microstructure with a two-phase mixture of Mo + n is seen in Fig. 2. The variation of the lattice parameter of n with the estimated composition is shown in in Table IA. The phase diagram does not agree with the results of Kuo9 who reported n2-Mo4Fe2C. Our lattice parameter Varies from 11.095A at the iron-rich end to 11.140Å at the molybdenum-richoend of the phase field whereas Kuo9reported 11.26Å for Mo4Fe2C. We are in agreement with the older work

Jan 1, 1970

By John Hall

SOME months ago one of the authors was asked to write a paper on the heat treatment of steel castings that would be more comprehensive than other matter lie had published; this is an attempt to present in condensed form the results of experimental work and actual practice carried out for the most part in 1907, 1908; and 1909. It is not a laboratory research and the work done was carried out for the express purpose of putting in practice the processes discovered as fast as possible. Most of the tests are the result of commercial practice and not of bars annealed in our laboratory; most of the micrographs were made for our own records and not for publication. Certain of the micrographs, therefore, are not as clear as we may wish but they were good enough for our purpose at the time they were made. The tests and micrographs are selected from several thousands in our files. All of these micrographs are magnified 60 diameters. These experiments were conducted almost entirely on steel made in a 3-ton bottom-blown converter, and most of the steel illustrated analyzes about 0.05 in phosphorus and sulfur. Unfortunately, a certain number of specimens are shown of which we do not have the complete analysis, but in most cases in which the phosphorus and sulfur vary much from the figure just given that fact is noted. For purposes of comparison, we have included a certain number of micrographs and tests of steel made in the electric furnace, some of which were from specimens made in other shops and some in our own shop, and some tests of acid open-hearth and tropenas steel.

Jan 9, 1919

By John A. Mathews

RESEARCH in the steel industry, as in other lines of manufacturing, has for its principal purpose the increasing of profits. That is what manufacturing companies are for, and all departments of the organization must be so coordinated as to lead to profitable operation. To divide a payroll into productive and non-productive labor is misleading. Productive labor, in fact, is necessary labor, and non- productive labor is the labor we can get along without. One might as well say that the steering wheel is not a part of an automobile as to say that the directing minds of an industry are non-productive. Legitimate manufacturing profits in a steel company or any other company are the reward that the public pays for service rendered or risk taken. The desire for profits is the impelling motive that leads investors .to take risks and build up industries that give employment to others. Every department of a company, be it executive, manufacturing, financial, sales, or research, must contribute to the one end which brings success-profits.

Jan 1, 1921

By G. M. Crosby

Seven mines with important production records in the Coeur d'Alene lie adjacent to the Gem stocks —the Frisco (Gem), Hercules, Interstate, Rex (Sixteen to One), Success (Granite), Sunset, and Tamarack. Old records are incomplete, but available data given in Table I show these mines have produced 10.550,721 tons of ore containing more than 50 million oz of silver, more than 1.5 billion lb of lead, and about 1 billion lb of zinc (approximately 1.25 million tons of lead and zinc combined). Average ore grade is 4.8 oz of silver per ton, 7.2 pct Pb, and 4.6 pct Zn. This impressive production represents about 12 pct of the District's yield. At present metal prices, with modern beneficiation, the gross value would be more than $400 million. THE GEM STOCKS The Gem stocks, considered to be outliers of the Idaho batholith of Late Cretaceous age, are located in the northern half of the Mullan quadrangle, and extend from the town of Gem, Idaho, along a strike of N30°E for a distance of approximately five miles. They occur as two major masses of monzonitic rocks commonly referred to as the North stock, which covers an area of 1.1 sq miles, and the South stock, which covers 2.6 sq miles. The areal pattern is roughly club-shaped, the North stock representing the handle and the South stock the head of the club. Two and a half miles west and five miles northeast are two groups of smaller stocks, isolated from the main masses but of the same general rock type. This discussion is limited for the most part to the North and South stocks. At the north end, where the intrusion is about 3200 ft wide, the walls are about parallel and dip very steeply west. At the south end, where the mass is about 7000 ft wide at surface, the walls dip away from each other at moderately steep angles. An aeromagnetic survey' detects and outlines with surprising accuracy the two main stocks. as illustrated on the magnetic contour map (Fig. 2). Of particular interest is the location and shape of the magnetic anomaly representing the South stock. The anomaly is centered over the south end of the outcrop, and a westerly extension joins it with a smaller anomaly over the Dago Peak stocks. The latter anomaly, likewise, is located over the south end of the isolated stocks. This pattern suggests the intrusion has greater extent at depth to the south and west. Though correlation between the Dago Peak stocks and the larger masses is suggested, the controversial aspects of the Dobson Pass fault, which separates the two areas, casts doubt on a correlation. Topographically the monzonite stocks are ignored by the drainage pattern indicating these rocks, and the invaded rocks of the Lower Belt Series react similarly to erosion. The drainage patterns of Nine Mile and Canyon creeks cut indiscriminately across the monzonite-Belt contact, resulting in both valleys and ridges in the southern end of the intrusion. Nine Mile Creek traverses diagonally the entire five-mile length of the stocks. The monzonite rocks of the intrusion are referred to locally as granite, but granite is rare and the rocks comprise a wide variety of types. Their characteristics, described in detail by F. L. Ransome and F. C. Calkins,' are summarized by P. J. Shenon.' The principal rock type is coarse-grained, light gray, porphoritic monzonite containing black crystals of hornblende. Pyroxene, epidote, and titanite

Jan 1, 1960

By AIME AIME

T HE 133rd meeting of the A. I. M. E., opening in New York on Feb. 15, promises to be as successful technically and socially as any in the past. The papers submitted for the various technical sessions are unusually excellent and insure something of interest to every group. Tentative programs have already been issued, and a concise resume of the various sessions, arranged chronologically, appears on page 48. Among the many interesting technical sessions arranged, attention is directed to those of the Petroleum Division, embracing the Symposium on Production that has come to be an annual feature, and new ones on refining practice, transportation and economics. The Institute of Metals program is similarly comprehensive. It includes 15 papers, 8 on copper, 4 on aluminum and its alloys, and one each on magnesium, lead, and fatigue of metals. The Coal Committee offers as a leading contribution its report, prepared under the direction of H. N. Eavenson, giving a new analysis of the capacity of the mines and a comparison of coal with other industries. This will be supplemented by a number of other papers of especial interest to operating men, among which are "Data on Use of Loading Machines in Bituminous Mines," by Graham Bright; "Evaluation of Coal," by R. H. Sweetser; "Selection of Coals for the Manufacture of Coke," by H. J. Rose; and "Relation of Origin and State of Carbonization of Coal to Problems of Low Temperature Carbonization," by S. W. Parr. The Iron and Steel Committee has scheduled seven papers, and there will be a special session on open-hearth practice, in which will be presented the first results of the two conferences, held by the sub- committee at Pittsburgh and Cleveland. A symposium on molding sands will be a special feature of the session on non-metallics.

Jan 1, 1926

By Herbert Hoover

DURING the year, the' Institute has made the most remarkable growth in its history. Our actual increase in membership was 1816 and therefore was 80 per cent. larger than any previous year. Even without expectation of any abnormal growth, we should pass in the year 1921 the 10;000 mark. The causes of this increased growth are not far to seek.. They lie in the widening vision of the Institute's work, not only in its relation to' the profession but as an avenue of service to the nation as a whole. The Institute is today in the first rank of influence among public institutions in the country. During this year we have, for the first time in many years, had a ?deficit of some $3000 in our finances. The sum is not important, but it- does indicate the tendency of the times, and that is the high cost of living:' The increase in our expenses lay, to the largest degree, on the publishing side of the Institute's work. If we compare the year 1918, as a fairly repre¬sentative year, with that of 1920, we find that the costs of issuing the' Institute's publications, after deducting the income received from these publications, shows a .net increase of about $33,000. for the year. This has been to some degree due to the enlarged membership but to a large degree due to the cost of the paper and printing.

Jan 1, 1921

By Oliver Bowles

ROCK is no doubt the most abundant of all material things because the planet on which we live is made of it. All animal and vegetable organisms and the multitude of natural and manufactured products that occupy a comparatively insignificant film on the outer surface of the planet are derived from rock. Processes of Nature acting for untold centuries have transformed rock into soil, making possible the development of vegetable and annual life; and rocks have supplied the numerous raw materials, metallic and nonmetallic, wherewith the innumerable appurtenances of a complex civilization have been fabricated. As time goes on we live with increasing speed and with enlarged desires. Time and space are shortened by man's ingenuity, and products for human use must be manufactured with greater and greater celerity. It was inevitable that Nature's slow processes of rock alteration should fail to keep pace with human demands and that the variety of natural products should fall far short of the requirements of an industrial age. Man therefore supplemented these processes by attacking rock in its native bed amid using it to supply needs not otherwise satisfied.

Jan 1, 1934

By AIME AIME

NEW place was assigned to the women for their headquarters at the annual meeting of the Auxiliary but they, as usual, occupied a large place in the activities of the annual meeting. The alcove on the Thirty-ninth Street side of the building was a busy place on Monday morning, as the members of the various sections from New York to California greeted each other. The registration was conducted under the supervision of Mrs. Wolfes, Miss Georgene Davis and Mrs. Jennings, while Mrs. Hursh, Mrs. Hyde, Mrs. Charlton Reynders, and others dispensed tickets to the various functions that had been provided for entertainment. There seemed to be the usual number registered, but when only one member of the District of Columbia Section made herself known everyone wondered why the large delegation of last year had so dwindled. The explanation appeared next day, when a number of others from that Section arrived, telling of a delightful reception on the night before, at the White House. Mrs. Hoover had honored the "Canaries"¬(the organization of Lone Girl Scout' workers) the officers of the Section, and their husbands, who for once became only "so and so's husband." Luncheon was served on the fifth floor on Monday, the hostesses for that day being Mesdames C. F. Ayer, Willis Burns, G. W. Farny, H. G. Moulton, and T. T. Read. A number of sight-seeing trips had been arranged for the afternoon. The most popular proved to be an expedition to the new Riverside Church; where Dr. Fosdick is pastor. Guides were there to conduct

Jan 1, 1931

By Robert E. Green, Kenneth Reifsnider

A microscopic X-ray diffraction technique was employed for the simultaneous study of the behavior of several families of lattice planes, whose local orientatiotz changes are manufestations of internal distortions resulting from specimen deformation. Photographs taken using aluminum were single crystals 1/64 in. In diam are presented which illustrate the appearance of various types of deformation- or growth- induced structural variations. Slip and lattice bending were detected in tensile tests for strains as small as 0.1 pct. Evidence of deformation bands, lineage structure, and void formation wns also shown. AmONG the most important methods of studying internal stresses in metals is the utilization of various X-ray techniques. The general subject of X-ray metallography has been treated in a most excellent manner by Taylor,1 and the use of X-rays for the direct observation of imperfections in crystals has recently been reviewed in an article by Newkirk2 and in the book edited by Newkirk and Wernick.3 Since the inception of metallographic X-ray analysis, there have been numerous technological developments and refinements, each with its particular advantages and disadvantages and, acrording to these, its particular applications. X-ray diffraction techniques can be divided into two general categories, that of X-ray diffraction microscopy and that of X-ray diffraction macroscopy. In the former are included such methods as those of Berg-Barrett, Lang, and Schultz2,3 which are concerned with microscopic imperfections such as dislocations. The second category includes all work concerned with the study of the condition of a crystal lattice structure as indicated by the marroscopic detail in its diffraction patterns. An example of this is the study of the diffraction manifestations of inhomogeneous plastic deformation as manifested by formation of deformation bands and inhomogeneous lattice rotations. The method used in the present investigation was an X-ray diffraction macroscopy technique. The geometry and analytical aspects of the method were similar to those of Julien and Cullity.4,5 The source was collimated with a single slit in a manner simi- lar to the "parallel beam'' method of Barth and Hosemann6 except that a continuous spectrum of radiation was employed. The apparatus produced large-beam transmission Laue patterns of thin cylindrical aluminum-wire crystals, which were deformed either in tension or torsion. Although the conventional X-ray target and interposed slit were not capable of the high resolution obtainable with a fine-focus X-ray source as employed in a microfocus apparatus, resolution was a secondary consideration in our technique, and was sacrificed to obtain sufficient intensity along a sizable length of the specimen. By using a grid indexing technique similar to that of Barth,7 we were able to study several diffraction lines from various planes simultaneously. The results of these tests give additional information with regard to the inhomogeneous deformation of single crystals, and the indexing procedure used provides a correlation between portions of the test specimen and portions of a diffracted beam. EXPERIMENTAL TECHNIQUE The experimental arrangement used is shown schematically in Fig. 1. A source of continuous X radiation from a vertically mounted Machlett X-ray tube possessing a copper target and operated at 20 kv and 10 ma was passed down a horizontal lead tube 80 cm long which terminated in an adjustable vertical brass slit. The slit opening was adjusted to correspond with the diameter of the test specimen. In front of the brass slit it was possible to place a screen wire mesh, one horizontal strand of which was a lead wire which served as a fiduciary mark, the screen itself serving as an indexing system as will be described later. Behind the screen was the test specimen which consisted of an aluminum single crystal wire 1/64 in. in diameter and 3 in. long. These 3-in.-long crystals were cut from

Jan 1, 1965

By B. E. Grant

THE major metal mine operations of the United States Smelting Refining and Mining Company in Utah are in the Bingham area. The Company also owns and operates metal mines in the Ophir district, twelve miles south of Bingham, and in the Tintic district, 28 miles south of Ophir. Operations of the Company in the Park City area have been idle since early in World War II. These mining camps, lying at moderate elevations, serviced by railroads, hard-surfaced highways, in close proximity to mills, smelters, cities and towns, fertile valleys, winter and summer vacation areas, and airports are probably as favorably situated as any mining camps in the world. The Bingham district, known principally for its copper production from

Jan 1, 1948

By David, Levinger

THESE observations of the metal-working industries of Europe are based on a three months' tour of eight countries of Europe, in which 75 industrial establishments were visited in England, France, Germany, Belgium, Holland, Italy, Austria and Switzerland during the summer of 1927. Since the Western Electric Co. is a large consumer of copper and brass, these industries were of particular interest and differences in practices were of keen interest to us.

Jan 1, 1928

Jan 1, 1880

By W. F. Domis, F. von Gemmingen, F. Garofalo

The effect of rain size on the creep behavior of an austenitic iron-base alloy has been studied at 1300° F under conditions of constant stress. The average grain diameter varied between 9 and 190 p (ASTM 10.7-2). The subgrain size and apparent activation energy for creep were not found to depend in any systematic manner on gain size. Grain hozmdary serrations were observed in all specimens tested. The variation of the secondary-creep rate, 2,, with the pain diameter, 1, is given by: es = K(213m + 1 )/l.]; 1, is the grain diameter zohere is reaches a minimum. Results in the literature shoujthat 1,increases as the temperature increases. At low creep temperatures is is therefore proportional to 12, at intermediate temperatures <, exhibits a minimum, and at high creep temperatures is is proportional to 1/1. The dependence ofis on the stress, u, is given by: t, = A" (sinh acrln, a and n show little variation with 1. The dependence of A" on 1 is given by: A" = KA[(21k + 13)/1]. For 1 » >>lmn = 4, and at constant values 01- isat lozu stress levels, the steady-state stress is given by the Hall-Petch relation. The variation of c, with grain size is believed to he associated particularly with grain boundary generation of dislocations which becomes more important with increasing temperatures. SEEMINGLY inconsistent experimental findings have led to a certain amount of confusion concerning the effect of grain size on creep behavior. The confusion is attributed to a lack of test results obtained over sufficiently wide ranges in grain size, stress, and temperature. Experimental results presented in this paper and results available in the literature1-5 show a consistent behavior and lead to a unified concept for the dependence of secondary-or steady-state creep rate on grain size. In accordance with this concept, which is substantiated experimentally, secondary-creep rate should increase with increasing grain diameter at low creep temperatures, leading to greater creep strengths for fine-grained materials. At intermediate temperatures the secondary-creep rate should decrease to a minimum and then increase as the grain size is increased. At high creep temperatures the secondary-creep rate should decrease with increasing grain size, leading to greater creep strengths for coarse-grained materials. Whether a temperature is high or low for creep in a metal or alloy depends primarily on its melting temperature. MATERIAL AND TEST PROCEDURES The material tested was an austenitic iron-base alloy of the following composition (wt pct): C, 0.005; N, 0.017; Mn, 1.26; Ni, 14.21; and Cr, 17.18. Two 15 -lb ingots were forged and hot-rolled to 5/8-in.-diam bars which were then cold-rolled and cold-swaged to a diameter of 0.49 in. These were sectioned into 3-in.-long blanks and heat-treated at various temperatures to obtain different grain sizes. The procedures employed and the results obtained are summarized in Table I. The secondary treatment at 1400° F followed the primary treatment without intermediate cooling to room temperature. This final treatment was employed to minimize various effects arising from heating to different temperatures during the primary treatment, particularly differences in intragranular dislocation structure, segregation of interstitial atoms at grain boundaries, and density of grain boundary ledges. The intragranular dislocation structure was examined by electron transmission metallography after each of the treatments described in Table I. Isolated dislocations and a few tangles were observed but no evidence of subgrains was found after any of the treatments. No grain-size effect was evident on the density and distribution of dislocations. Stabilization of grain boundary structure is particularly important because, as will be discussed later, grain boundaries influence high-temperature creep behavior. Magnetic-permeability measurements after each treatment and

Jan 1, 1964