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By L. L. Wyman

SINCE the observations of Heyn,1 relative to the embrittlement of copper after having been heated in hydrogen, this subject has received considerable attention from later investigators. The published works of Archbutt2 and of Bengough and Hill3 give the reasons for this embrittlement-the formation of steam by the reaction between cuprous oxide and hydrogen. From Ruder,4 Pilling,5 Moore and Beckinsdale,6 Bassett and Bradley,7 and from Smith8 can be obtained quantitative data concerning the action of hydrogen and other reducing gases on copper samples having various oxygen contents. This problem has been discussed from a practical standpoint by Fuller9 who calls attention to some of the instances of this embrittlement encountered in the manufacturing field. The examples he cites may be considered typical cases of copper embrittlement which were incident to the process of manufacture. In many cases, such difficulties are overcome by changes in the manufacturing process.

Jan 1, 1931

By W. J. Babyak, J. M. Sheehan, H. W. Paxton

THE- solubility of hydrogen and deuterium in solid niobium up to I-atm pressure has been established bv a number of workers.1-5 X-ray examination at room temperature of specimens reacted in hydrogen at high temperatures from 300° to 1000°C shows the presence of two phases—a bcc phase (a) based on the niobium lattice and with an u0, increasing from 3.30A for Nb to 3.32Afor NbHo.L, and an orthorhombic phase6n = 4.84A, h=4.90A, c =

Jan 1, 1960

Jan 1, 1958

By A. R. Troiano, A. B. Greninger

There is need for an adequate working hypothesis that would describe at least qualitatively the crystallographic mechanism for the transformation from austenite to martensite in steel. A general theory would not only be of great assistance in the correlation of existing data and in planning future experimentation, but would also form the basis for an eventual explanation of the property changes that accompany lattice transformations. The mechanism of martensite formation described in the following pages is the outcome of two new experimental determinations: (1) the accurate evaluation of the lattice relationship between austenite and individual crystals of martensite, and (2) the measurement and analysis of the change in position that a volume of austenite undergoes when it transforms into a crystal of martensite. For this latter study, the stereographic analysis of shear was employed; this method greatly simplifies the solution of lattice-shear problems, and some space is devoted to its description. Lattiice Relationships and Habits PREVIOUS WORK The lattice relationships between austenite and martensite in carbon steels have been studied by Kurdjurnow-and Sachs,' and by Wassermann;2 and in iron-nickel alloys by Nishiyama.3 Wassermann,2 and Mehl and Derge.4 The studies by Kurdjumow and Sachs and by Wassermann were made on single (austenite) crystals of quenched 1.4 pct carbon steel, and the results of these two independent studies agree closely with the postulated lattice relationships: (III)r||(0ll)a [101]r [111]a [1] Both Nishiyama and Wassermann worked with an alloy of iron plus 30 pct nickel (all austenite at room temperature), and "martensitic alpha" was formed by cooling in liquid air. They agree that the lattice relationships for these conditions are: (lll)r||(011)a [112]r[011]a [2] Mehl and Derge worked with a range of iron-nickel alloy compositions centered about 30 pct nickel. They concluded that when the transformation takes place near room temperature or above, relationship [l] holds, but if the same specimen is made to transform at -195°C, relationship [2] obtains;intermediate temperatures evidently produced a combination of these two relationships. Sachs and co-worker~,1,7 as well as Nishiyama,3 have proposed transformation mechanisms for martensite formation.* Both of the mechanisms picture the transformation as initiated by shearing movements along the octahedral [Ill] plane of austenite, followed by suitable expansion and contraction to complete the transformation. These mechanisms have been described and commented upon by Mehl, Barrett, and Smith,8 Mehl and Derge,4 Wassermann,2 and others, and generally accepted by investigators in this field. Greninger and Troiano9 have recently published the results of a detailed study of the shapes and orientation habits of martensite crystals in plain-carbon and nickel steels. They found that, contrary to previous assumptions, martensite plates form not along the octahedral planes but along austenite planes of very high indices; these results were in line with those of previous studies of martensite reactions in nonferrous alloy systems by Greninger and coworkers.6,10 Greninger and Troiano concluded that the transformation theories of Kurdjumow and Sachsl and of Nishiyama3 are untenable. Phragmén11 reached a similar conclusion. EXPERlMENTAL METHODS The object of this particular study was the evaluation of (1) lattice relationship between austenite and martensite, and (2) relationship between the martensite lattice and the martensite plate. The technique used for solving these problems was similar to that used by Greninger6 on martensitic structures in 8 copper-aluminum alloys. Briefly, the method consists of grinding and polishing a specimen on a surface parallel to an individual martensite plate and thus exposing a single martensite crystal for an area of l to 3 mm. The orientation of this exposed martensite crystal is then determined by means of a back-reflection Laue X ray pattern.12 Another pattern is obtained from the matrix crystal, and a stereo-graphic plot of data from these two patterns then provides the solution to the problem. It is necessary to repeat this process on several crystals in order to determine whether or not the solution is unique.

Jan 1, 1950

By W. A. Riggs

In a single year the total transportation cost equals nearly 30 pct of the value of mineral commodities, the largest single cost from the deposit to consumer. The magnitude of this economic factor calls for more complete understanding of cost and operational problems between producer and carrier than now exists. Details are given of the costs of providing transportation as well as freight rates for selling transportation. In 1958, transportation of mineral commodities in the United States required 600 billion ton-miles to move 1 3/4 billion tons of products of mines comprising solid fuels, crude oil, industrial minerals and rocks, and ores. Possibly 17 pct was handled by more than one mode of transport, since combinations of several modes of transport may, at times, achieve better service/cost results than any single mode. Total transportation cost of nearly $5 billion equaled roughly 30 pct of the value of the mineral commodities, the largest single cost from the mineral deposit to the consumer. The tremendous magnitude of this transportation undertaking demands much more complete understanding than now exists between mineral producers and carriers about the economic and operational problems of each other. A substantial portion of the daily work of the writer is spent in trying to act as a combination interpreter and catalyst between potential shippers and carriers, hoping to direct both to points of mutual understanding and advantage. For the purpose of this paper, it is necessary to ask mining people to accept some terminology and to try to appreciate the mental approach of the freight rate making people of the carriers. This paper will consider costs of providing transportation as well as freight rates for selling transportation—although these are fields of limited certainty. There are no accurate statistical breakdowns for all modes of transport and types of carriers indicating commodities, volume of traffic, distances, costs, and rates. Much information is available for railroads, and some for the regulated portions of air, motor, pipeline, and water transportation. Unregulated carriers, handling about half of the transportation of products of mines, are not required to report, and very little is known of their activities. Figures used herein are national in scope, unless otherwise indicated, and have generally been derived from Interstate Commerce Commission reports and files. Tonnage figures have been reduced to net tons of 2000 lb. The very generalized comparison of average mileage freight rate levels for various modes of transport provided by Fig. 1 affords advantageous perspective for the entire field of transportation costs. Dashed guide lines show cents per ton-mile, and dotted guide lines show percentage of first class railroad freight rate. While costs of other than railroad transportation more nearly follow constant cents per ton-mile functions, costs of railroad transportation show characteristic taper, or decrease in cents per-ton mile with increasing length of haul. This fundamental difference in cost is due largely to the fact that railroads and pipelines provide their own fully taxed roadway facilities while highway, waterway, and air carriers use government-provided tax-free roadway at no cost other than fuel, license, and certain excise taxes. Thus railroad and pipeline transportation might be said to carry heavy threshold costs in addition to those transportation costs which are directly variable with ton miles of transportation produced. The original basis of railroad freight rate structures lies in the classification of all articles of commerce into railroad class ralings ranging from 7 to 40 pct of first class (100 pct) rate level, dependent on value, hazard, loading characteristics, service requirements, and whether carload or less than carload. Classification tables and mileage-based (but arbitrarily grouped), rate scales are published as tariffs subject to approval by regulatory bodies. Used together, these determine class rates in cents per 100 lb between points in the U. S. Where local commercial or operating conditions render it advantageous for carriers to depart from

Jan 1, 1961

By R. G. Garlick, H. B. Probst

Tungsten single-crystal specimens of various orientations were deformed in tension at room temperature. Slip traces indicated both (112)(111) and (110) (111) slip; however, about 10 pct plastic dejormation was required bejore these traces could he seen. Resolzled shear-stress considerations indicated that at least some of the particular systems observed were not those on which slip initiated hut were secondary systems. This is highly probable, considering the high plastic strains involved. Analysis of the stress data with respect to possible slip systems indicated that slip must have been initiated at stresses below the proportional-limit stresses measured. ALTHOUGH there is general agreement that slip deformation in fcc and hep metals takes place on the plane of close packing and in the direction of close packing, there is no such agreement for slip in bcc metals. It is generally agreed that the close-packed direction (111) is the slip direction, but investigations have led to conflicting descriptions of the slip plane. As Hoke and Maddin1 point out, there are essentially four points of view. 1) Deformation in bcc metals is composite shear on (112) and (110) planes or on nonparallel (110) planes, and any apparent slip on other planes can be accounted for completely by slip on these planes. Chen and Maddin have reported this to be the possible case for molybdenum." 2) Slip occurs in the (111) direction and is limited to {110), {112), and (123) planes (the three closest packed planes of the lattice). 3) Slip occurs in a (111) direction, but not necessarily on planes of close packing (banal slip). 4) Slip occurs in those directions and on those planes for which ß, the ratio of Burgers vector to interplanar spacing, is a minimum. The slip systems of the bcc metal tungsten have never been fully determined, although several investigators have reported pertinent results.3"7 The present work was initiated to determine the active slip systems in tungsten at room temperature, the critical resolved shear stresses associ- ated with these systems, and the orientation dependency of operative systems. These features of tungsten deformation at room temperature have never been reported in the literature. The authors find this somewhat surprising, particularly in view of the availability of tungsten single crystals since the advent of electron-beam zone-melting techniques and the widespread interest in refractory metals. It would seem apparent that such work has been attempted but the results have not been reported, possibly due to the conflict with deformation theory. The results of the present work conflict with any straightforward description of deformation based on the proposed explanations of slip in bcc metals. Although these conflicts have not been resolved, a presentation of the problem seems in order and should be of value to others working in this field. MATERIALS AND PROCEDURE Single-crystal tungsten rods of 1/8-in. diameter were grown from undoped commercial rod by one-pass electron-beam zone melting in apparatus previously described by witzke.8 Representative analyses of the rod before and after melting are given in Table I. There was no detectable zoning of impurities during melting. Buttonhead tensile specimens, as shown in Fig. 1, were machined from single crystals. Two flats 90 deg apart were ground in the gage length of each specimen. These flat surfaces facilitated the analysis of slip traces. No attempt was made to position these flats with respect to the crystal orientation. The worked surface layer of the machined specimens was removed by electrolytic polishing in a NaOH solution. Tensile-axis orientations were determined by standard Laue back-reflection techniques. The sharpness of the Laue spots indicated that the crystals were free of strain.

Jan 1, 1964

By R. F. Domagala, D. J. McPherson

Iodide zirconium was combined with calculated amounts of ZrO2 or master alloys and arc-melted. Annealing treatments were carried out at 21 temperature levels. Metallographic examination of the heat treated specimens permitted construction of the binary phase diagram from zirconium to ZrO2. Oxygen additions to zirconium raise the transformation temperature as well as the melting point. Features of the diagram include the peritectic formation of beta, the formation of alpha directly from the melt, an intermediate phase ZrOB with a' range of homogeneity, and a eutectic between alpha and Zr02. PHASE relationships in the Zr-0 system were determined in the range 0 to 66. 7 atomic pct 0 (ZrO,). Arc-melted alloys were annealed at temperature levels between 600" and 2000°C. Determination of the phase boundaries was accomplished by metallographic evaluation of specimens quenched from the various temperatures. Incipient melting techniques were used to determine solidus curves, and X-ray diffraction work was employed to study the lattice parameters of the a solid solution and the phase ZrO,. Experimental Procedures Westinghouse "Grade 1" iodide zirconium crystal bar (approximately 99.8 pct pure) was employed for the investigation. This material is substantially free of the impurity inclusions characteristic of most zirconium metal. Previous work has shown it to be the most satisfactory grade for phase diagram studies. The zirconium crystal bar, as-received, was coated with corrosion product from autoclave tests by which its grade designation is determined. The bars were sand blasted lightly, pickled for 1 min in a 20 pct HN0,-5 pct HF aqueous solution, rinsed in water and acetone, and dried. The bars were rolled to about 1/32 in. strip, cut into 10 in. lengths, and pickled again. The material was sheared to approximately Y4 in. squares, cleaned with acetone, and stored for use. Two pounds of specially prepared "chemically pure," and 100 grams of spectrographic grade ZrO, were obtained for the preparation of alloys. The "Specpure" ZrO, was obtained from Johnson, Mat-they Co.. Ltd.. and Titanium Alloy Manufacturing Div. of National Lead Co. supplied the other grade of oxide. The "chemically pure" material (henceforth referred to as C.P. ZrO,) was used for the preparation of all alloys employed in the determination of phase relationships. A limited number of alloys were prepared with the "Specpure" oxide to recheck certain phase boundaries. Analyses of the two grades of oxide are given in Table I. The C.P. ZrOI was received in powder form, not suitable for arc melting. Therefore, this material was compressed to wafers 1 in. in diameter and about Vn in. thick. These were segmented and stored for use. The "Specpure" material, in the form of small granules, was suitable for use in the as-received condition. A nonconsumable electrode arc-melting furnace was used to prepare alloys. A water-cooled copper crucible and tungsten-tipped electrode were employed. The material was placed in the crucible and rapidly melted under a protective atmosphere of helium gas by striking the arc on a tungsten stud and directing it upon the charge material. Details of operation, including drawings of this type furnace, have been published.'

Jan 1, 1955

By Frederick Laist

THE object of the construction and operation of the 80-ton leaching plant was to test out the leaching of sand tailings on a large scale and, if possible, determine a definite method of operation, and the best construction for the larger unit which is now being built. It was also of importance to obtain some practical data as regards cost items. The 80-ton plant was not expected to be a commercial success. A leaching process on such low-grade material necessitates the treatment of a very large tonnage.. Such a cost item as labor, for instance, is entirely out of proportion in such a small plant. The amounts of acid, salt, scrap iron, and fuel for roasting, however, are the same per ton in an 80-ton plant as in a 2,000-ton plant. These costs were definitely established. Also the percentages of extraction and grade of tailings were definitely determined for a large-sized unit. Following will be found the description of the plant, the method of operation and the results obtained. A -general view of the plant is given in Fig. 1. The bins consisted of one coal bin with a capacity of 30 tons, one salt bin with a capacity of 20 tons, and a "mill tailings" or feed bin which held 70 tons. The coal and salt bins were placed with their floor level even with the firing floor of the roasting furnace. The feed bin, to give it greater capacity, discharged about 12 ft. below this point, to a 12-in. conveyor belt, which, in turn discharged into a pug mill. This fed another conveyor belt, which discharged into the top hearth of the furnace. The furnace was an ordinary six-hearth MacDougall roaster, .20-ft. in diameter. It was equipped with two fire boxes, on opposite sides, the flames entering on the third hearth. An induced draft was obtained with a Buffalo blower, worked as an exhaust fan. Just above the top hearth was an annular flue around the whole circumference of the furnace. Slots at intervals of about 18 in. led from this flue down into the top hearth. The slots were 2 in. wide by 6 in. long. This annular flue proved rather unsatisfactory, as it tended to fill up with flue dust and choke the slots, thus cutting down the draft. The volume of gas through

Jan 8, 1914

By John Hays, Hammond

IT is both a pleasure and an honor to be a guest of the Institute and I thank you, Mr. President and fellow-members, for giving. me the opportunity of meeting you this evening. My esteemed friend, President Smith, has requested me to do a bit of "reminiscing" as to the earlier years of my career as a mining engineer, which has now covered a period of fifty years. Let me reassure you by promising that my narrative will not include all the experiences I have had over that long period. You will, I trust, pardon what might seem egotistical but I do not see how a personal narrative could well be otherwise.

Jan 1, 1928

By T. N. Rhodin

There can be two types of films on solids, those which are stable in mono-layers and those which tend to aggregate into three dimensional structures. A great number of metal films formed by condensation onto a solid base are unstable in the sense that they will aggregate into crystals providing the atoms possess sufficient surface mobility. The crystalline structure of the film is strongly influenced by the base in many systems and, in some cases, a single orientation prevails when the force fields around the atoms in the supporting crystal are sufficiently strong.' Relatively little is available in the literature about the nature of these forces and the role they play in promoting a preferred orientation of the atoms arriving at the substrate surface. An understanding of their periodicity and magnitude relative to the surface forces characteristic of the film itself should provide insight into the critical dependence of film orientation on the nature and temperature of the substrate. In addition, this effect may be very useful in preparing samples for surface studies. The study of the physical and chemical characteristics of pure metal surfaces has been severely handicapped by the presence of strongly adherent foreign films. Furthermore, the randomness of the surface orientation has obscured interpretation of experimental results. Evaporation of metals in high vacuum onto carefully selected substrates under ideal conditions for preferred orientation appears suited to the preparation of flat, oxide-free, oriented films for surface reaction studies. Many factors influence their structure and some understanding of the mechanism of their formation is a necessary prerequisite for obtaining satisfactory surfaces for study. The dominant factors in defining film structure are film thickness and growth rate and the nature, condition, and temperature of the substrate. GENERAL ASSEMBLY The system was enclosed in an 18 in. bell jar which rested on an L-shaped neoprene gasket on a ground steel plate as indicated in Fig 1. Rapid evacuation of the system to 10-6 mm mercury was facilitated by a 4 in. manifold, 2 in. packless valve, and an extra large diffusion pump. Suitable arrangement of valves on a secondary manifold readily permitted introduction of purified gases

Jan 1, 1950

26. G. H. S. Price, S. V. Williams, and G. J.O. Garrard: Heavy alloy, its production. properties and uses. Metal Industry (1941) 599 354s 372. 394. 27. R. Kieffer and W. Hotop: p. 320 of ref 12. 28. F. R. Hensel. E. I. Larsen, and E. F. Swazy: Physical properties of metal compositions with a refractory metal base. Chap. 42, 483, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 29. R. Kieffer and W. Hotop: p. 290 of ref. 12. 30. H. Freundlich: Kapillarchemie. 211 (1923) Leipzig. 31. W. Ostwald: Zisch. f. Phys. Chemie. (1900) 34, 503. 32. G. A. Hulett: Zisch. f. Phys. Chemie. (1901) 37. 385; and (1904) 47, 357. 33. J C. Chaston: Discussion to Price, Smithells and Williams, p. 257 of ref. 4. 34. W. Dawihl: Untersuchungen ueber die Vorgaenge bei der Abnuetzung von Hartmetallwerkzeugen. Ztsch. f. techn. Phys. (1940) 21 336. 35. W. Dawihl and J. Hinnueber: Ueber den Aufbau der Hartmetallegierungen. Kol-loidzlsch. (1943) 104, 233. 36. F. Skaupy: Dispersoidchemische und verwandte Gesichtspunkte bei Sinter-hartmetallen. Kolloidzlsch. (1942) 98, 92; and (1943) 102, 269. 37. F. C. Kellcy: Cemented tantalum car- bide tools. Trans. ASST (1932) 19, 233. 38. E. W. Engle: Cemented carbides. Chap. 39, 436, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 39. W. Dawihl: Zlsch. f. Melallkunde. (1940) 32, 320. 40. P. M. McKenna: Tool Materials (Ce- mented Carbides). Chap. 40. 454. Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 41. G. A. Meerson. G. L. Sverev, B. Y. Osinovskaja: Zhurnal Prikladnoi Khimii. (1930) 139 66. 42. A. G. Metcalfe: The mutual solid solubility of Tunesten Carbide and Titanium carbide- Metal Trealmenl (1946) 13, 127. 43. P. Schwarzkopf: Powder Metallurgy. 196-201 and 354-356 (1947) New York. 44. H. Burden: The manipulation and sintering of hard-metals. Special Rep. No. 38, p. 78. Iron and Steel Inst.. 1947. London. 45. W. D. Jones: Principles of powder metal- lurgy. 150. (1937) London. 46. J. E. Drapeau: Sintering of powdered copper-tin mixtures. Chap. 32. 332, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 47. H. E. Hall: Sintering of copper and tin powder. Metals and Alloys (1939) 10, 297. 48. F. Sauerwald: Present status of powder metallurgy. -.Melallwirlschafl. (1941) 20, 649. 671. 49. H. L. Wain: Powder metallurgy; influence of some processing variables on the properties of sintered bronze. Report ACA-25. Australian Council for Aeronautics (1946) Melbourne. 50. S. L. Hoyt: Constitution of copper-tin alloys. Metals Handhook, 1364. (1939) Cleveland. 51. T. Ishikawa: Studies on the interdiffusion of copper, tin and graphite powders. Nippon Kinzoku Gakkai-Si (1937) I, 226. 52. A. Carter and A. G. Metcalfe. The struc- ture of porous bronze bearings. Special Rep. No. 38, p. 99. Iron and Stecl Inst. (1947) London. 53. R. P. Koehring: Sintering atmospheres for production purposes. Chap. 25, 278. Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 54. C. G. Goetzel: Some properties of sintcred and hotpressed copper tin compacts. Trans. AIME (1945) 161, 569. 55. J. W. Lennox: The production of some non ferrous engineering components by powder metallurgy. Special Rep. No. 38. p. 174. Iron and Steel Inst., 1947, London. . P. Duwez and H. E. Martens: The power metallurgy of porous metals and alloys having a controlled porosity. TP 2343, Metals Tech. April 1948. This volume. p. 848. 57. E. A. Owen and L. Pickup: X-ray study of the interdiffusion of copper and zinc. Proc. Royal Soc., London, Series A. (1935) 149, 283. 58. C. G. Goetzel: Sintered and hotpressed compacts of copper-zinc powder. Chap. 34. 352, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 98, R. Chadwick. E. R. Broadfield, and S. F. Pugh: Observations on the pressing. sintering, and properties of iron-copper powder mixtures. Special Rep. No. 38, p. 151, Iron and Steel Inst. (1947) London. 60. A. Squire: The properties of iron-copper compacts. Watertown Arsenal Lab. Rep. WAL No. 67101. 61. F. C. Kelley: Properties of sintered iron- comer uowder. Iron Age (Aug. 15. 193) 158 57. 62. G. H. Howe: Sinterinn of Alnico. Iron Age (Jan. 11. 1940) 14.5, 27. 63. R. Kieffer and W. Hotop: p. 359 of ref. 12. 64. W. Hotop: Permanent magnets from sintered iron-nickel-aluminum. Stahl und Eisen (1941) 61, 1105. 65. P. R. Kalischer: Some experiments in the production of aluminum-nickel-iron alloys by powder metallurgy. Trans. AIME (1941) 145, 369. 66. S. J. Garvin: Production of sintered per- manent magnets. Special Rep. NO. 38. p. 67. Iron and Steel Inst. 1947, London. 67. F. C. Kelley: Discussion to P. R. Kalischer. p. 375 of ref. 65. 68. R. Kieffer and W. Hotop: p. 357 of ret, 12. 69. C. H. Howe: Sintered alnico. Chapter 48, 530, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. Powder Metallurgy Seminar (C. G. Goetzel presiding) C. G. Goetzel—The seminar has been opened by a man who has been active in the field for over fourteen years and has made, since then, some major contributions to the advancement of the art. After having been associated with the Moraine Products Division of General Motors Corporation for over ten

Jan 1, 1949

By Charles S. Barrett

The experiments reported in this paper have been fruitful in disclosing the mechanism of the deformation of iron in compression. They have established the nature of "deformation bands," "etch bands," or "X-bands," that have been a recognized but little understood feature in the structure of cold-worked metals since the early days of metallography, and have shown the role of the bands in the development of preferred orientations by cold-working. The work has also shown the relation of the orientation of individual grains to the preferred orientation of the aggregate. Some of the methods previously used in the determination of the indices of slip planes and slip directions are shown to be untrustworthy in the presence of deformation bands. The conclusion is reached that many slip planes and slip directions must operate during each stage in the compression of a single crystal, and that theories failing to take account of this require revision. In conducting the experiments a method of compression has been used by which extreme reductions can easily be reached, even to the limit set by the metal's capacity to deform without fracture. The work is a portion of a research program on the plastic properties of iron and steel. It is being used as a foundation for studies of orientntions resulting from recrystallization and is being extended to other metals and other types of deformation. Previous Work The previous experiments are few and have given confusing results Onol compressed a polycrystalline alpha-iron specimen between two flan plates of a testing machine and found that severe deformation oriented the crystals into a duplex preferred orientation, one set of crystallites having a cube diagonal of the body-centered cubic lattice parallel to the compression axis, and another set having a cube axis parallel to the compression axis. We shall speak of this structure as a double fiber texture of the type [111] + [100]. Wever2 also made an X-ray determination of the texture

Jan 1, 1939

By Charles S. Barrett

The experiments reported in this paper have been fruitful in disclosing the mechanism of the deformation of iron in compression. They have established the nature of "deformation bands," "etch bands," or "X-bands," that have been a recognized but little understood feature in the structure of cold-worked metals since the early days of metallography, and have shown the role of the bands in the development of preferred orientations by cold-working. The work has also shown the relation of the orientation of individual grains to the preferred orientation of the aggregate. Some of the methods previously used in the determination of the indices of slip planes and slip directions are shown to be untrustworthy in the presence of deformation bands. The conclusion is reached that many slip planes and slip directions must operate during each stage in the compression of a single crystal, and that theories failing to take account of this require revision. In conducting the experiments a method of compression has been used by which extreme reductions can easily be reached, even to the limit set by the metal's capacity to deform without fracture. The work is a portion of a research program on the plastic properties of iron and steel. It is being used as a foundation for studies of orientntions resulting from recrystallization and is being extended to other metals and other types of deformation. Previous Work The previous experiments are few and have given confusing results Onol compressed a polycrystalline alpha-iron specimen between two flan plates of a testing machine and found that severe deformation oriented the crystals into a duplex preferred orientation, one set of crystallites having a cube diagonal of the body-centered cubic lattice parallel to the compression axis, and another set having a cube axis parallel to the compression axis. We shall speak of this structure as a double fiber texture of the type [111] + [100]. Wever2 also made an X-ray determination of the texture

Jan 1, 1939

By E. M. Wise

THOUGH known as the platinum-group metal- the sextuplet, platinum, palladium, iridium. rhodium, osmium, ruthenium, might well be called the American metals or perhaps Pan-American metals, as the ore containing them eras first discovered in South America, and in recent years the largest production has come from North America. The South American alluvial deposits, which also, contain gold, are in active production, as are the alluvial platinum deposits of Alaska, but the main production is from the copper-nickel ores of Sudbury, Ontario. The Russian deposits in the Urals were the source of most of the worlds platinum for about 100 years, but since 1934 have assumed second place. For a time considerable amounts of platinum came from several rather rich deposits in South Africa but these were exhausted quickly. However, a tremendous reserve of lower-grade ore exists there, which could be worked profitably if the price of platinum were considerably higher.

Jan 1, 1942

By E. J. MCOAUSTLAND

THE behavior of steel after overstrain and at moderate temperatures is fairly well known. It has been made the subject of much investigation, and our knowledge is clear and definite on many points. The ultimate raising of the elastic limit, after moderate overstrain, and the consequent lowering of the ductility, seem to be well established. It is also well understood that the immediate effect of overstrain is to lower the elastic limit, possibly to zero, but that if not interfered with, this limit will subsequently rise higher than before. The "tests after moderate temperature," reported in this paper, were undertaken to verify the above statements for the particular steel under investigation, and also to determine, if possible, the total time required for complete recovery from this state of overstrain. The behavior of overstrained steel at temperatures at or below 32° F. is not so well known. Tests made by Prof E. G. Coker, at McGill University,' show that steel, overstrained and subjected to cold, will remain in a state of overstrain for an indefinite period. I am not aware of any other published results of tests along this particular line. The effect of time and temperature on the recovery of steel from overstrain was made in 1902-3 the subject of sortie investigation in the laboratories of the College of Civil Engineering of Cornell University. A general plan was outlined in connection with the regular courses of instruction in testing of materials; but the press of routine work and the demands of the schedules on the time of the students were so great as to presage long delay in the completion of the work. Not much had been accomplished up to 1904-05, when Messrs. E. C.

May 1, 1906

INTRODUCTION Data available on prophyry copper occurrences in the Andean, Caribbean, Appalachian, and Cordilleran orogens may be categorized in a manner to suggest a hypothetical evolution for deposits that occur in the western hemisphere. A classification of de- posits is also suggested. A classification dependent on internal structure of a porphyry copper deposit would lead to two broad categories, breccia pipe and stockwork models. A classification of this type is examined herein but it is not universally accepted in the literature. Modeling based on igneous petrography as well as metasomatism attendant with the sulfide mineralization is more widely accepted by economic geologists whose evaluation of porphyry systems is influenced by the presence or absence of a phyllic zone. Lowell and Guilbert model deposits ordinarily include a phyllic zone, whereas those of the diorite model do not. Position of the phyllic zone in the alteration sequence is a significant ore guide. Should the phyllic zone be absent, dependence on alteration zoning to identify metallization is weakened. Presence or absence of the phyllic zone therefore is a significant parameter in the economic evaluation of a porphyry copper deposit (Hollister. et al., 1975). The Lowell and Guilbert (1970) model commonly includes a phyllic zone in quartz- bearing rocks. Parameters of both calc-alkalic and the quartz monzonite models mentioned elsewhere in this volume are sufficiently close to the Lowell and Guilbert (1970) model that it should be expanded to encompass them. The diorite model remains separate and distinct because deposits of this type are characterized by an absence of quartz in the pluton, commonly highly gold: copper ratios, low molybdenum content, and regular absence of sericite in the alteration zones. Therefore, for the benefit of those

Jan 1, 1978

By Joel Watkins

THE terms kaolin, china clay, ball clay, and paper clay are more or less loosely and interchangeably applied to a large class of white-burning clays. These clays are made up chiefly of hydrous amorphous (colloidal) aluminum silicates with variable amounts of free silica and other impurities in small quantities. Occasionally also the term kaolinite is wrongly applied to a white-burning clay, for kaolinite, is a mineral of definite chemical composition and definite crystalline form which occurs but sparingly in nature. It is not the purpose of this paper, however, to define or classify clays, or to enter into a discussion of the chemistry of clays. It is rather a general description of the occurrence and methods of mining of a kindred group of clays, and a discussion of their future economic aspect. In the Southern Appalachian States, the mining of white-burning clays has in recent years become an important industry. Although these clays are of several distinct types, which occur in as many localities under different geologic conditions, they are for the most part. primarily of the same origin. They are essentially the same in elementary constituents, and are largely consumed in the same industrial arts. From the standpoint of a mining engineer, therefore, and for convenience in comparison and correlation, it should be interesting to discuss them under one heading.

Jan 2, 1915

Discussion of the paper of Earl S. Bardwell, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 79, July, 1913, pp. .1429 to 1441. H. O. HOFMAN, Boston, Mass. (communication to the Secretary*) :-It is pleasing to the originators of the planimetric determination of oxygen in refined copper to see that the method has been taken up by a large smelting plant to be used in every-day work after it has been simplified to suit the new conditions. Several years ago Huntington and Desch 1 had improved our mode of working. They projected the developed negative on to a screen, traced the outlines of the picture with a pencil, drew a border, and measured one constituent with. the planimeter. In order to give the work greater precision, they divided the area into squares of 1 cm. side, shaded the

Jan 11, 1913

By M. L. Millican

The objective of this study has been to develop a method of log interpretation in the Delaware sand whereby the effects of the shale contained within the sand can be recognized and accounted for in a quantitative solution for porosity and water saturation. Both theoretical and empirical considerations are discussed. A simplified interpretation chart is presented which provides a means of amending the conventional porosity resolution of the Sonic log to compensate for the presence of shale. The amount of shale within the sand and its degree of lamination may be inferred from a calibrated gamma ray log. The resulting porosity value may then be used in conjunction with a knowledge of the formation resistivity to determine water saturation. Of added interest, particularly in the Delaware sand, is an approximation of permeability which may be derived empirically from the simplified chart. The discussion is illustrated by field examples. INTRODUCTION The performance of the Sonic log in defining the porosity fraction in clean, consolidated formations is well known, particularly in sandstones that are well compacted and free of shale. An approach to Sonic log porosity determination in shaly sands has been recently developed.' This method involves correcting the Sonic log readings by means of an a factor, where a is the ratio of the pseudo-static SP to, the static SP, and is a function of the amount of shale present. This method is dependent upon a contrast between the salinities of the drilling fluid and the connate water in the formation, inasmuch as this contrast produces the SP effect. In wells drilled with salt mud, the contrast, and with it the means of obtaining the a correction, disappear. In the Delaware basin, the large majority of rotary wells drilled to the uppermost sands of the Bell Canyon group employ salt mud as the drilling fluid. These sands have been the objective of most of the drilling exploration in the basin to date. A comparison of porosity values in these sands, as determined by core analysis, to Sonic log readings has indicated that a correction for the shaliness of the sand is needed. In the absence of an SP curve to determine the correction factor, the porosity resolution of the Sonic log in these sands has been questionable.

By S. Katz, M. E. Nicholson, J. J. Kelly, D. R. Curran

A series of wedges of 1020 steel (2 1/2 by 6 by 8 in.) were explosively loaded, as shown in Fig. 1. A slab of explosive on the surface of the steel wedge was initiated simultaneously along one edge, producing an essentially two-dimensional oblique shock in the metal. Pressure and density in the metal were measured as a function of distance from the explosive-metal interface by a method described elsewhere.' While for pressures below 130 .kbars the technique produces accurate results, for greater pressures the presence of two shock waves in the metalzy3 makes interpretation of the data uncertain. However, the location of the transition in pressure at 130 kbars can be readily identified from the data. The assumption of a single shock in the region above 130 kbars overestimates the pressure computed on a multiple-shock model. After firing, the wedges were sectioned, lapped, and etched with 2 pct Nital. A photograph of an etched specimen is shown in Fig. 2. The specimens were examined metallographically. The dark region, at the top of the specimen, was heavily banded, Fig. 3, while the lighter area was comparatively free from banding, Fig. 4, the boundary between the two regions being quite abrupt. The very light regions at an angle of about 45 deg to the explosive-metal interface show virtually no banding. The origin of these light regions, which are not Luder's bands, is not yet explained. The thickness of the heavily banded area was measured and compared with the pressure at the boundary between the heavily and lightly banded regions. The results of these measurements and calculations are given in Table I. For all shots, the pressure at the boundary is approximately the same

Jan 1, 1960