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By J. Handin, S. J. Bauer, M. Friedman

Deformation mechanisms in room-dry and water-saturated specimens of Charcoal Granodiorite, shortened at 10-4s-1, at effective pressures (Pe) to 100 MPa and temperatures to partial melting (?1050°C) are documented with a view toward providing criteria to recognize and characterize the deformation for geological and engineering applications. Above 800°C strength decreases dramatically at effective pressures ? 50 MPa and water-weakening reduces strength an additional 30 to 40% at Pe = 100 MPa. Strains at failure are only 0.1 to 2.2 percent with macroscopic ductility (within this range) increasing as the effective pressures are increased and in wet versus dry tests. Shattering (multiple faulting) gives way to faulting along a single zone to failure without macroscopic faulting as ductility increases. Microscopically, cataclasis (extension microfracturing and thermal cracking with rigid-body motions) predominates at all conditions. Dislocation gliding contributes little to the strain. Precursive extension microfractures coalesce to produce the throughgoing faults with gouge zones exhibiting possible Riedel shears. Incipient melting, particularly in wet tests, produces a distinctive texture along feldspar grain boundaries that suggests a grain-boundary-softening effect contributes to the weakening. In addition, it is demonstrated that the presence of water does not lead to more microfractures, but to a reduction in the stresses required to initiate and propagate them.

Jan 1, 1982

By Charles C. Fatino, Joel S. Hirschhorn

Loose compacts of strained and annealed stainless-steel powders were sintered at various temperatures and times to determine the effect of residual strains on the sintering behavior. The atomized powders were prepared by annealing, ball milling, and rean-nealing. The residual strains and domain size were determined by a Fourier analysis of X-ray diffvaction dala. The specimens were prepared by siwzultaneously sintering cylinders of both strained and unstrained powder. The evaluation of the sintered compacts included density measurements, metallographic examinations, and analyses of X- ray diffraction data. The results of these studies reveal a definite increase in sintered density and sintering rate for the strained powders. THE pressure compacting of metal powders causes deformation of the particles, mechanical interlocking, and increased contact area. After the deformation, severe residual strains remain in these particles. The subsequent contributions of these strains to the sintering process have been considered to be negligible, since the recovery and recrystallization temperatures usually occur prior to the temperature required for the sintering process. Sintering is con-sidered to be the process by which the powders are transformed into solid compacts at temperatures below their melting points. The sintering operation for stainless steel usually takes place in the range of 2050" to 2400°F (0.84 to 0.95 T,, where T, is the absolute melting point or liquidus temperature) while the temperature required for recovery is approximately 1800°F (0.75 T,). However, it has been shown for several metal powders that densification becomes significant in the range of 0.35 to 0.45 T,.' It is the purpose of this study to determine what effect residual strains have upon the sintering behavior of stainless-steel compacts. Loose compacts were selected for study in order to isolate the strain contributions and eliminate the variables inherent in sintering of pressure-formed compacts. Additional variables were minimized by using only one mesh size, one composition, one particle shape, and also by simultaneously sintering both types of powder. Very little work has been carried out previous to the present study to delineate the effect of strains on sintering behavior. Lenel et 01.2 observed that residual stresses in copper compacts caused shrinkage at comparatively low temperatures. Delisle3 loose-sintered ball-milled electrolytic iron and observed that bonding among particles began at a lower temperature as compared to the behavior of annealed powder. Increased densification of ball-milled oxide powders has also been noted.4'5 EXPERIMENTAL PROCEDURES Powder Preparation. The powder used for this study was a commercial-type 316L stainless steel made by the atomization process. A typical chemical analysis is: C- 0.025 pct Mo- 2.2 pct Cr-18.6 pct Ni-12.5 pct Fe—Balance The atomizing process is essentially the rapid freezing of liquid droplets. This nonequilibrium cooling causes coring to occur and two distinct phases are present within the solid particle, the austenitic phase and the ferritic phase. Due to the presence of this ferritic phase, the particles tended to fracture as well as become cold-worked during the subsequent ball-milling operation. (It was also found that this type of cooling produced a broadened and shifted

Jan 1, 1968

By Peter J. Conroy, Julianne H. Gyarmaty

INTRODUCTION The current study is part of the U.S. Department of Energy's (DOE) on-going subsidence research program. The long-term objective of the DOE program is to develop analytical methods of subsidence prediction applicable over a broad range of geologic and mining conditions encountered in the United States. The DOE currently has several contracts in progress to develop a sound data base that can be used in the development of predictive models. Dames & Moore is currently under contract to DOE to collect and analyze detailed subsidence and hydrologic data from a coal mine employing longwall mining methods in the Eastern Coal Province. Work under Contract No. DE-AC22-80PC 30335 began in October of 1980 and will continue through September of 1984. The contract includes monitoring of two adjacent longwall panels. This paper summarizes the surface monitoring work that was performed through February of 1982. Mining of the first of the two panels (3 off 3 north) was completed on February 3, 1982. Results of the surface monitoring through completion of this panel are presented and discussed. SITE DESCRIPTION The mine being studied is located in eastern Ohio. The site is west of the Ohio River, approximately 56 km (35 miles) south of Wheeling, West Virginia. The topography of the unglaciated region

Jan 1, 1982

By G. W. Traer

THE distillation of bituminous coals at what is commonly termed low temperature, and the quantities, nature and adaptabilities of the products have been the subject of considerable experimentation, during recent years. Fortunately, the earlier work in this country was done by men whose scientific training qualified them properly to record and interpret the results of-their experiments. The work of Prof. Parr, of the University of Illinois, is especially notable in this respect. Prof. Parr's work, added to that of English experimenters, demonstrated certain things to a degree which is generally regarded as convincing. They have proved that a caking bituminous coal, when subjected to a temperature of not more than 1000° F. (preferably somewhat less) will yield light tar having low specific gravity (about 1.06) and high value; also, that this yield, with a given coal, will depend upon the percentage of hydrocarbons in the coal, the maximum temperature used, and the promptness with which the distillate gases are removed. It is assumed that air is excluded from the retort, and that the coal is subjected to heat for a sufficient time to drive off all of the tarry hydrocarbons. The results attained in the first, or low-temperature stage of the Carbocoal process, recently described by C. T. Malcolmson, corroborate these general principles. It is the purpose of the writer to describe other work of a practical nature, directed toward the commercial adaptation of these principles, which was begun nearly two years ago; this investigation was assisted by A. J. Sayers, of the Link-Belt Co., and Carl Scholz.

Jan 9, 1918

By Samuel M. Dunaway

INTRODUCTION ASARCO Incorporated purchased the East Tennessee Zinc Mines of the American Zinc Company and commenced operating on November 29, 1971. Presently, three mines are operating producing 6620 t/d (7300 stpd). The ore mined is sphalerite which occurs In lower Ordovician carbonates of the upper Knox Group and occurs in open space and fracture filling. Orebodies range from 3 to 46 m (10 to 150 ft) thick with dips from flat to 20º. The mining method is random room and pillar modified by shrinkage and bench stoping. Like other mining departments, the mining group at the Tennessee Mines Division is constantly looking for methods to improve productivity and safety and to reduce mining costs. This involves testing new equipment, trying new ore extraction ideas and making mining plant alterations to meet changes in operating conditions. The areas of change that will be described in this paper are longhole raising, jumbos and LHD loading, shaft sinking, conveyor transport of ore and sublevel haulage developments. LONGHOLED RAISES Raise driving has always been a hazardous occupation for miners and today it is becoming more difficult to get competent people for this kind of work. This problem has led us to seek an easier, safer way in which to excavate raises. The first longhole raises were excavated in the early 1970's using a Gardner-Denver air trac equipped with a PR-123 rock drill. The machine used 38 mm x 244 cm (1 ½ in x 8 ft) round rods with rope

Jan 1, 1977

Book Review MANAGEMENT AND MEN. By Meyer Bloomfield, Boston. The Century Co., New York, 1919, pp. 584, H.X. 5 1/2. $3.50. This hook is an exposition of English efforts to solve the problem of labor unrest in England. The first six chapters are reprinted from articles published in the Satur-day Evening Post, for whom the author went to England to study the problem at first hand. These articles deal with housing, increased production, eliminating the internal friction in the industrial machine and a chapter each devoted to the view-point of employer and employee. These chapters are written in the easily readable magazine style and give a complete general survey of the particular solution being tried. Perhaps their greatest., certainly not their least, worth lies in the fact that they form a vehicle for unusually voluminous appendices containing in full the famous Whitley Reports which are the basis of the new movement, together with various reports, which, except for this publication, would be largely inaccessible to those inter-ested in this country. The Whitley scheme considers each industry a unit and proposes to establish therein a Joint Standing Industrial Council composed of representatives of employers and employees to consider appropriate matters affecting the industry at large. There is to be a District Council for each industry which will, as its name implies, deal with the clatters pertaining to that interest in. the particular district. The third and last body in this scheme of Industrial Parliament is the Works Committee, which is com-posed of representatives of the management and of the workers employed in particu-lar plants or mines to act in close cooperation With the district quid national machinery. The Whitley or similar schemes have been tried in many communities in England and the book contains interesting comments on the result obtained, it being notable that most of the objections conic from plants which have not tried the scheme. Meyer Bloomfield, the author; is the specialist in industrial personnel problems who organized the industrial service activities of the United States Shipping Board, Emergency Fleet Corporation. P. E. B.

Jan 10, 1919

Discussion of the paper of L. C. MORGANROTH, presented at the Pittsburgh meeting, October, 1914, and printed in Bulletin No. 93, September, 1914, pp. 2345 to 2352. D. T. DAY, Washington, D. C.-I would like to hear some further detail as to the California deposits. L. C. MORGANROTH, Pittsburgh, Pa.-We have examined the California deposits at various times; I have been over practically all of them myself. These deposits are all of the massive variety. While it is possible that it could be mined and used for metallurgical purposes, it is not feasible because it costs too much. At the present time magnesite which is mined in California is used in the making of plaster, or by the paper trade. Careful figures show that if the California magnesite could be delivered to Atlantic seaports in the crude state at not over $4 a gross ton, and assuming that it would give the same results as the Austro-Hungarian magnesite, it would be cheaper to use the latter. It is also more difficult to dead-burn the massive magnesite, for while it starts to give up its gas readily, the difficulty consists in driving off the last few per cent., and unless this is driven off the magnesite will absorb C02 from the air, so that in a few months it may have 10 or 12 per cent. DAVID T. DAY.-How is the Austro-Hungarian supply at the present time ?

Jan 4, 1915

UNIVERSITY OF ALABAMA University, Ala Mining and Metallurgical Society G T Bator UNIVERSITY OF ALASKA College, Alaska Mining Society Earl H Beistline-

Jan 1, 1952

By Henry Knox

AMIDST the tumult and the shouting of the times, there are perceptible certain tendencies, quiet though serious, to take stock of the situation with a view to putting our house in order, and of these none is more encouraging than the awakening, interest in the higher education, and especially in technical education. Various committees of the professional organizations have cast much light on the matter and have pointed the way to progress and reform, but their scope is necessarily restricted by the requirements of precision and any excursion beyond these bounds must be undertaken by the unfettered individual who is free to rush in where responsible committees fear to tread. A discussion of the bearing of the higher education on character scarcely lends itself to objective treatment and yet, fraught as it is with imponderables and abstractions, the theme cannot be escaped in any com-prehensive scheme of education. The question is being pressed with growing insist-ence, why these United States, relatively to Europe, are deficient in intellectual output, and the ready reply, "Because America is a new country and Americans are too intent on developing their natural resources," is too facile and too false to carry conviction.

Jan 12, 1922

By Junichi Sato, Takash Suzuki, Tatsuo Imamura, Mamoru Hojo

INTRODUCTION Hitachi Refinery of Nippon Mining Co., Ltd. was constructed in 1911. The refinery began early to recover by-product metals and to manufacture copper products. Today, the refinery recovers gold, silver, selenium, platinum and palladium as by-products of the copper refining process and manufactures copper powder, copper foil, wire bars and chemicals for plating. In 1969, the capacity of the Hitachi Refinery reached 6,000 tons/month. (T/M). Because, at that time, the forecast was for the demand for copper in Japan to increase, planning for the expansion of the Hitachi and Saganoseki refineries was begun. A new 10,000 T/M capacity tank house, a new electrolyte purification plant and a enlarged anode slime treatment plant were planned for the Hitachi Refinery. Construction at the Hitachi Refinery began in December, 1970, and was completed in April, 1974. The development of new machines and processes has resulted in an efficient refinery with a production capacity of 16,000 TIM. This paper is a report on the new anode slime treatment plant at the Hitachi Refinery, and especially on the copper removal process in that plant, the Ferric Leaching Process.

Jan 1, 1976

By J. E. Burke, C. W. Mason

IN attempting to study precipitation from a tetragonal lattice using solid solutions of bismuth in tin, it was found that although a Widnmanstatten pattern is observed 1 only a qualitative analysis of the orientation relationships is possible, because of the unusual structural changes that accompany the precipitation process MICROSCOPICAL STUDIES Alloys were made from Chempur tin (Standard samples 42b and 42c, National Bureau of Standards), and bismuth (Kahlbaum C P ) by melting neighed quantities together under palm oil, stirring well, and casting in a heated graphite mold The polishing and etching techniques employed largely govern the visibility of the structural changes The preliminary surfacing operations were similar to those recommended by Villela and Bergekoff,5 through BehrManning 3/o abrasive papers, lubricated by a solution of paraffin in kerosene A rough metallographic polish was next given, using a thin cotton cloth charged with relevigated alumina (maximum particle size of about 4µ) and soap solution, repeated etching and polishing served to remove disturbed metal For high-power examination better preparation was necessary It was found that on such soft metals the threads of the fabric, rather than the abrasive, cause most of the scratching Cotton outing flannel, which had been brushed so that the nap lay down, was fairly satisfactory, but a Heavy grade of silk velvet (not the noncrushable kind) was found to be better, especially after some use A better procedure was as follows The metal lap was warmed slightly, and a 4-in circle of woolen broadcloth was cemented to its center by a thin film of melted paraffin The broadcloth was then moistened with water, and a 30 to 40 per cent solution of sodium hydroxide heated to about 50°C was poured over it, allowed to stand for 1 to 2 min and then washed off It was neither necessary nor desirable to remove all the sodium hydroxide from the cloth, since its etching action aided in the removal of the flowed layer from the sample The cloth was then charged with a paste of the relevigated alumina in water Since this lap did not remove deep scratches, it was necessary previously to polish the specimen on some material such as the silk velvet The sodium hydroxide softens and partly gelatinizes the woolen lap covering, permitting a scratch-free polish, but its action continues, and the cloth deteriorates after about 24 hr This is not serious, because a new lap can be prepared in about 5 min, and only small pieces of cloth are used Etching with a strongly acid solution of ferric chloride was found satisfactory for removing the flowed layer For the final etching, the most satisfactory reagent was that of Taffs,7 the formula for which is FeC13 6H20, 2 grams, HC1, 5 c c , H2O, 30 c c , C2H5OH (95 per cent), 60 c c This etchant reveals differences in com-

Jan 1, 1941

University or College Society President Secretary Alabama, University of University. Ala Mining and Metallurgical Society Warren G. Payne Melbon J. Langley Alaska Agr. College and School of Mines, College, Alaska Alaska Mining Society Robert McCombe Robert Mize Arizona, University of, Tucson, Aria Miners' Society Frank Bacon Charles V.' Harris California University of, Berkeley, Cal...: Students Mining Association C. F. Bedford J. R. Hollcraft, Jr. Came is Inst. of Technology, Pittsburgh, Pa The Miners and Metallurgists Society Richard M. Barnhart Jack E. Morris Case School of Applied Science, Cleveland, Ohio Pick and Shovel Club R. H. Randolph W. B. Scott Colorado School of Mines, Golden, Colo Student Branch of A. I. M. E, Donald Peaker T. H. Evans Jones Harvard University, Cambridge, Mass Geological Club H. E. Quinn Lincoln Thiesmeyer Idaho, University of, Moscow, Idaho Associated Miners John T. Carpenter Robert D. Baily Illinois, University of Urbane, Ill Mining Society H. M. Adams R. M. Sherer' Kansas University of, Lawrence, Kane : Student Branch of the A.I.M.E. Henry Gould Everett Stidham Kentucky, University of, Lexington, Ky : Norwood Mining and Metallurgical John D. Lancaster James A. Purnell

Jan 1, 1929

By H. S. Bell

IT SEEMS unnecessary to dwell upon the advantages of the modern pipe still as compared with the older type of distillation equipment used by oil refiners. The relatively low installation cost, coupled with remarkable operating efficiencies of pipe stills, precludes the consideration of other types except in rare instances where some peculiarity of product or plant may have an influence. The question of the actual heat required to distil petroleum is quite involved. We have extensive data on the latent heats of the various hydrocarbons under different conditions of pressure. We also have information regarding the specific heats of various oils and the effect of temperature thereon. Because of the complexity of petroleum and of each fraction, it seems impossible to theoretically analyze the partial-pressure effect of the great number of hydrocarbons upon one another during distillation. If a distillation curve and percentage analysis of any crude or product are available, it is possible to construct a curve with ordinates representing per cent. distilled and B. t. u. per pound or per gallon, or other desired unit. To do so the crude is split into fractions, of 5 or 10 per cent. The boiling point and gravity of each fraction being determined, it is possible to evaluate the heat required. As each fraction is removed, the residue must be raised to a higher temperature and latent heat supplied for the successive fraction. As the calculations progress, the latent heats decrease while the specific heats increase. Such a curve is illustrated by Fig. 1 for a typical 39.9 B° North Texas crude.

Jan 1, 1928

G. R. DELAMATER,* Steelton, Pa. (written discussion t)..-Under the heading, "Preparation of Coal," Mr. Campbell discusses the ad-visability of sizing the coal for the jigs. While I fully realize that conditions alter cases, my method at all times is to do everything possible to avoid sizing. It would be unwise for anyone to say that greater ash and sulfur reduction is impossible by sizing. The thing that can be questioned is, will the greater reduction be sufficient to counterbalance the greater cost? The same thing is true of the proper size of crushing for each individual proposition. In past years many washeries have been built and equipped for wash-ing two or more sizes, but I know of few instances where these plants were operated more than a year before sizing was abandoned. Perhaps in some of these cases this was clue to lack of sufficient development of such scheme of operation; yet I have found that most men engaged in this work, including myself, started into the work with a pretty well-fixed idea that sizing would be beneficial. But trials and tests showed that the mixed size washing is necessary for coals requiring crushing to 1 in. or less. Coal is of low value, compared with other minerals segregated by washing or concentration, for which reason simplicity must be the watchword: simplicity in the machine used to attain the separations of impurities from the coal, in the accessory plant equipment, and in its arrangement.

Jan 12, 1919

By W. F. Vietti

Operations in the Texas Gulf Coast during the past year have resulted in the discovery of a number of new fields arid the extension of a few of the older fields, both by deeper drilling and by lateral development. Twenty-six new oil and gas-producing areas and discovery of oil or gas in three subsequently abandoned wells have been recorded for a total of 29 new fields of varying importance. Producing areas at Conroe, Manvel, Greta, Pierce Junction, Hastings, Dirks, Thompson, Batson, Mykawa, Tomball, Raccoon Bend, Samfordyce arid Saxct have been increased. Primary geologic studies followed by geophysical mapping or straight geophysical prospects have been responsible for the more important discoveries. These methods have further proved themselves an aid to limiting wildcatting to the more prospective areas and as the chief means to discover reserves in the future. Production for 1935 totaled 69,560,720 bbl. as compared with 60,850,-360 bbl. for 1934. Strict proration has been in force throughout the discovery of more oil than has been produced. The number of producing oil wells has steadily increased to 4851 at the end of 1935, as compared with 3858 at the end of 1934, owing in part to the prolonged life, because of proration. There were 1272 oil and gas wells completed during 1935, as against 835 in 1934. New Fields Pertinent data on the new fields discovered during 1935 are includrd in Tables 1 and 2. Hence, the discussion of these discoveries will be limited. Bee County.—Three new gas fields were added during the year: Beeville, discovered by G. M. Church in No. 1 Wood on Sept. 21; Foley, discovered by Dirks Bros. in No. 1 Foley on Feb. 8; and Plummer, discovered by Hynes and Fisher in No. 1 T. M. Plummer on Sept. 2. The three new oil fields added are: Hartzendorf, drilled on fee land by Hartzendorf and completed on May 17 as a small pumper; Ray, southwest of Tuleta, and discovered by Jameson and Burns in No. 1 Campbell

Jan 1, 1936

By W. F. Vietti

Operations in the Texas Gulf Coast during the past year have resulted in the discovery of a number of new fields arid the extension of a few of the older fields, both by deeper drilling and by lateral development. Twenty-six new oil and gas-producing areas and discovery of oil or gas in three subsequently abandoned wells have been recorded for a total of 29 new fields of varying importance. Producing areas at Conroe, Manvel, Greta, Pierce Junction, Hastings, Dirks, Thompson, Batson, Mykawa, Tomball, Raccoon Bend, Samfordyce arid Saxct have been increased. Primary geologic studies followed by geophysical mapping or straight geophysical prospects have been responsible for the more important discoveries. These methods have further proved themselves an aid to limiting wildcatting to the more prospective areas and as the chief means to discover reserves in the future. Production for 1935 totaled 69,560,720 bbl. as compared with 60,850,-360 bbl. for 1934. Strict proration has been in force throughout the discovery of more oil than has been produced. The number of producing oil wells has steadily increased to 4851 at the end of 1935, as compared with 3858 at the end of 1934, owing in part to the prolonged life, because of proration. There were 1272 oil and gas wells completed during 1935, as against 835 in 1934. New Fields Pertinent data on the new fields discovered during 1935 are includrd in Tables 1 and 2. Hence, the discussion of these discoveries will be limited. Bee County.—Three new gas fields were added during the year: Beeville, discovered by G. M. Church in No. 1 Wood on Sept. 21; Foley, discovered by Dirks Bros. in No. 1 Foley on Feb. 8; and Plummer, discovered by Hynes and Fisher in No. 1 T. M. Plummer on Sept. 2. The three new oil fields added are: Hartzendorf, drilled on fee land by Hartzendorf and completed on May 17 as a small pumper; Ray, southwest of Tuleta, and discovered by Jameson and Burns in No. 1 Campbell

Jan 1, 1936

By A. J. Opinsky

ThE superior performance of nonsag tungsten wire in lamps has been ascribed to the large-grained micro-structure that can be developed in it. The orientations of these large grains have been studied several times; most published data1-' appear to be similar to those plotted in Fig. 1. These new data were obtained by X-ray back-reflection Laue technique from all of the large grains occurring in thirteen different wires that had been heated at the lowest possible temperature for the formation of large grains. Here the wire axis is plotted in terms of the principal directions of the cube. Rosi decided that the preferred orientation of the large crystals could be described by a single ideal orientation, (531), being parallel to the wire axis.' Rieck2,3 and Mannerkoski' have essentially confirmed this finding. Opinsky, Orehotsky, and Seigle argued that the data suggest that (211) is parallel to the wire axis instead of a single ideal orientation.5 This {211} contains the (531) ideal orientation and would appear to be a more general case. Ahlborn and Wassermann report that their orientation data stretch from ( 110) through (531) to (311) 8 This is part of the locus of (211). All these investigators have determined the orientations of the large grains by back-reflection Laue techniques. They have all obtained essentially similar results. On the other hand, Swalin and Geisler, who obtained their data by neutron diffraction, indicated that the preferred orientation of the large grains in doped wire is (110) .7 These findings cannot presently be reconciled with the pole density data described in the previous paragraph. Rosi1 and Rieck2 have advanced arguments about how their orientations could occur. Nevertheless, the crystallographic link between the (110) (cold-worked) fiber texture and the preferred orientation of the large grains has remained missing. This link can be provided through the concept of coincidence-type boundaries. Such boundaries separate two grains that have a certain number of common lattice sites. Coincidence relationships that result from rotations about low index directions are given by Brandon et a1 .' What is desired is a calculation of those orientations that bear a coincidence relationship with the (110) fibers of the cold-worked matrix. This situation arises in the following fashion. Heating the tungsten wire for a combination of time and temperature falling short of the formation of the nonsag structure yields a structure that is still fibrous in nature and the preferred orientation remains (110). During grain growth, the growing grain is in contact with these fibers. It is hence possible that the entire process may begin by the passage of a coincidence boundary into a (110) fiber. The calculations were carried out analytically and checked graphically. Following Brandon et a1.,8 coincidence relationships from 1 in 5 to 1 in 19 have been considered. The results of the calculations are given in Fig. 2. Of the coincidences examined, some of those occurring upon rotation about ( 110) come closest to the experimental points in Fig. 1. Nineteen of the twenty-three data points in Fig. 1 can be attributed to the ideal orientations A, B, C, and D in Fig. 2. As determined analytically, three crystals lie within 4 deg of point A, four lie within 21/2 deg of point B, eleven lie within 5 deg of point C, and one lies within 1 deg of point D-a total of nineteen. The off-lying points are near the |110| point of the triangle.

Jan 1, 1968

By AIME AIME

AS one of his friends asserted at the Galveston meeting last fall, T. V. Moore is one of the "thinkers" in his field. He is head of production research for the Humble Oil & Refining Co., with headquarters in Houston. He is also known in the Institute as a "doer" for his active participation in the affairs of the Petroleum Division and for his leadership in the formation of the present Gulf Coast Section, A.I.M.E.

Jan 1, 1940

By R. G. Davies

WeERTMANI has shown that the high temperature steady state creep rate, i, in lead and indium-base alloys obeys an equation of the form where AH is the activation energy, o the applied stress, n the stress exponent, and R and T have their usual meanings. He observed a variation in n from 4.5 for pure metals to 3 for concentrated alloys, which he interpreted as due to Change in creep mechanism from the climb of dislocations in pure metals to a micro-creep mechanism in the alloys. The Cottrell-Jaswon microcreep mechanism of the moving dislocation taking its impurity atmosphere with it was considered to be the most likely process, although short-range order and the segregation of solute atoms to a stacking fault will also give a stress exponent of 3. Steady state creep has been investigated in a Au - 27 at. pct Cu alloy at temperatures above 1/2 TIM where TIM the absolute melting temperature. As the oxidation resistance of this alloy is excellent all tests were carried out in air with a furnace built to give a temperature variation of less than 1°C along the 60 mm gage length. A lever-arm arrangement applied the stress with a load being adjusted between each creep test to maintain a constant stress. As each test produced less than 0.5 pct creep strain, the variation in stress during the test was negligible. The creep strain was measured by a transducer at the end of one of the alloy-steel grips, with the out of balance potential being finally recorded on a variable speed chart recorder. A typical creep curve is shown in Fig. 1. The results, Fig. 2, confirm that n is nearer to 3 than to 4.5; the creep mechanism could be any of those given above. The activation energy, AH, which is independent of stress, is consistent with a diffusion controlled process; the activation energies for the self-diffusion of gold and for the diffusion of gold into Copper are both -45 kcal per ml., There is now considerable evidence, that, when the steady state creep is dependent upon diffusion, irrespective of the actual creep mechanism, the activation energy is independent of the stress. The author would like to acknowledge the financial assistance provided by the International Atomic Energy Agency, Vienna, and the Argentine Atomic Energy Commission.

Jan 1, 1962

By S. K. Nowak

The lithium solubility limit in solid aluminum was determined by the use of micro-graphic techniques. The solubility limit thus established was shown to be a true equilibrium by checking the reversibility of AlLi phase precipitation and dissolution around the equilibrium temperature. The experimental results fit a straight line by plotting log N(LI) against 1/T. The metallurgical reasons explaining the lack of agreement among previous investigations are discussed. THE solubility limit of lithium in solid aluminum was determined by Shamray and Saldau1 by micrography and by Grube et al.' and also Voss-Kiihler- by measurement of electrical resistivity. Since the addition of lithium induces extremely small changes in the aluminum lattice, X-ray techniques could not be employed for this purpose; in fact, the addition of lithium does not cause an expansion of the lattice as might be expected from a consideration of atomic radii, but causes a small contraction from 4.040 to 4.037A3, 4 when the solvent aluminum is saturated with this element. An analysis of the results from previous investiga-tions'" shows that with improvement of investigation techniques the solubility limit tends toward a lower lithium content. Again, some of the author's own experimental results on the action of atomic hydrogen on A1-Li alloys seemed to indicate that the solubility of lithium should be much lower, i.e., about 0.3 pet at 300°C: instead of 1.15 pet, the lowest published value.4 For the foregoing reasons it was decided to investigate this problem. The aluminum and the lithium used for this purpose were of the highest purity. The lithium solubility limit was determined by metallographic techniques, in particular by the use of a reagent especially developed for the purpose of revealing the AlLi phase. The solubility limit thus determined was shown to be a true equilibrium by checking the reversibility of AlLi phase dissolution and precipitation around the equilibrium temperature. All of the experimental work was carried out in 1951 at the Centre d'Etudes de Chimie Metallur-gique at Vitry, France, under the direction of Georges Chaudron.

Jan 1, 1957