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By A. Soundraraj, S. Singh, R. C. Deshpande

THE detonation of a high-explosive charge having a metal-lined conical cavity (shaped charge) results in a fast-moving jet and a slow-moving slug.1-4 Clark and Bruckner reported the metallographic studies of a cast-iron slug. The present note describes the metallographic studies of a copper slug and discusses the principle of flow involved. The shaped charge consisted of a 5-cm diam cylinder of cast high explosive (60-40 RDX-TNT mixture) having a 45 deg and 0.16-cm thick copper cone. The copper (99.5 pct purity) had a grain size of 0.06 to 0.08 mm diam and a hardness of 65 to 75 Hv. These were fired into a deep container of water and the slugs were recovered undamaged. The longitudinal and transverse sections of the slug were polished, etched, and examined for mi-crostructural changes. Macroexamination revealed a radial grain flow inwards towards the center and a downward component of flow towards the base of the slug. Fig. 1 shows schematically the micro-structural changes observed on the longitudinal section of the slug. The region D near the apex and also along the outer surface of the slug was characterized by the presence of heavily deformed and twinned grains. Some of the grains were having bent or crossed twins, Fig. 2. The grain size in this region was of the same order as that of the

Jan 1, 1960

United Engineering Society WILLIAM L SAUNDERS,, President GEORGE H PEGRAM, 1st Vie-president ALFRED D FLINN, Secretary J V W REYNDERS, 2d Vice-president JACOB S LANGTHORN, Treasurer HENRY A LARDNER Assistant treasurer Finance Committee House Committee GEORGE H PEGRAM, Chairman ALFRED D FLINN, Chairman J 'VIPOND DAVIES FREDERICK F SHARPLESS BANCROFT GHERARDI . JOHN H DUNLAP WILLIAM L SAUNDERS CALVIN W RICE W F M GOSS, ex-officio F L HUTCHINSON

Jan 1, 1923

A special meeting of the Institute, at which the Institute of Metals Division will join with those members who are most interested in iron and steel, and in coal and coke, will be held in Milwaukee, Wis., October 8 to 11, 1918. The technical program is as follows: INSTITUTE OF METALS DIVISION Tuesday morning, October 8: The Metallography of Tungsten, by My Jeffries. (Bulletin No. 138, p. 1037.) The Constitution of the Tin Bronzes, by S. L. Hoyt. Paper, title not given, by C. H. Mathewson. Notes on Babbitt and Babbitted Bearings, by Jesse L. Jones. (Bulletin. No. 140, p. 1397.) Oxygen and Sulphur in the Melting of Copper Cathodes, by S. Skowronski. (Bulletin No. 135, p. 645.) The Relation of Sulphur to the Overpoling of Copper, by S. Skowronski. (Bulletin No. 135, p. 651); with discussion by Philip L. Gill. (Bulletin. No. 140, p. 1156.)

Jan 9, 1918

By Tegner C. Johnson

Just a few years ago, my company was referred to as the Marion Steam Shovel Company. Though we still make shovels, both two and eight-crawler types, the eight-crawler stripping shovel appears to have been replaced by the walking dragline for overburden removal and in some cases for the mineral as well. The walking dragline appeared in the coal fields in the early 1930's. It is popular because it can cope with overburden depths in excess of 100 ft and with blasted sedimentary rock, all at an O & O (ownership and operational) cost of ±10[c] per bank cu yd (bcy).

Jan 10, 1974

By E. W. Johnson, M. L. Hill

The dijfusiuity D was determined at 25° to 780°C- from hyd?-ogen evolution rates. Anomalous evolution from air-melted iron was att~zbztted to residual hydrogen, which is interpreted as a hydrogen compound that decomposes at a strongly temperature-(Ieperzdent rate above 500°C. Above 200°C, D = 0.0014 cm2sec-1 exp (-3200 cal per g atom/RT). Below, 200°C the diffusivity is anomalously low and represented by D = 0.12 cm2sec-l exp (-7820 cal per g atom/RT). It is postulated that at low temperatures the hydrogen in the metal is "trapped" with an energy 4.8 kcaL per g atom below- that of the interstitial hydrogen. 1 HE purpose of the present experimental study was to determine the diffusivity of hydrogen in a-Fe over an extended temperature range. As certain anomalies were encountered, attempts were made to understand the anomalies themselves. This research was in progress both before and after a determination of the diffusivity of hydrogen in nicke1.l The latter system was found to exhibit none of the anomalies of hydrogen in iron, and its description was far simpler. The experiments on nickel also

Jan 1, 1961

By C. Schlumberger, M. Schlumberger

In order to explore electrically a terrain composed of a succession of horizontal beds, a current of known intensity i is caused to flow between two grounds A and B, and the resultant drop of potential , caused by the resistance of the earth, is measured between two given points in the soil, M and N. In practice it is convenient to choose the two points M and N so that they lie on the line AB and their midpoint coincides with the middle 0, of that line, although this is not imperative. When the lengths L and I of the two lines AB and MN are varied, equations are obtained which may be solved for the resistivity p of the subsoil at various depths. Recall briefly that the formula 4 x l gives the average resistivity, in the horizontal direction, of a layer of earth which extends to a depth1 about equal to L/4. This elementary concept is adequate for numerous practical applications. Nevertheless, it must be said that, in many cases, a rigorous mathematical analysis may be made, provided it is always a question of homogeneous, superposed horizontal beds. The authors expect to publish, later on, appropriate methods of calculation for some specific cases.

Jan 1, 1932

ALABAMA Alabama City.-Eddy, L. Altoona.-Cain, J. America.-Foreman, J. T. Anniston.-Foster, R. N. Ashland.-Sturdevant, J. C. Bessemer.-Ball, E. M. Calhoun, F. W. Maschmeyer, W. L. McKenzie, W. C., Jr. Birmingham.-Abbott, C. E. Aldrich, T. H. Aldrich, T. H., Jr. Ashton, J. J. Aufderhaar, H. C. Ball, T. L. Biddison, P. M. Blair, C. S. Brown, T. S. Bush, M. W. Clark, G. H. Crawford, G. G. Crockard. F. H.

Jan 1, 1929

[University of Alabama University, Alabama Mining and Metallurgical Society Meets first and third Mondays each month WILLIAM L. ALLMAN, President L. M. LOTOTZIY, Secretary J. R. CUDWORTH, Faculty Sponsor RICHARD L. BOWRON, Counselor University of Arizona Tucson, Arizona Miners' Society HARRY GARRETT, President AL WALLACH, Secretary A. J. THOMPSON, Faculty Sponsor E. D. GARDNER, Counselor Birmingham-Southern College Birmingham, Alabama Geology Journal Club WALTER WOLF, President LELAND CULLIGAN, Secretary R. S. POOR, Faculty Sponsor A. J. BLAIR, Counselor]

Jan 1, 1940

AIMS 1953 DIRECTORY SUPPLEMENT OFFICERS AND DIRECTORS 1953 President and Director ANDREW FLETCHER (2) New York City Past President and Director MICHAEL L. HAIDER (2) New York City President-elect and Director LEO F. REINARTZ (3) Middletown, Ohio Vice-Presidents and Directors 0. B. J. Fraser (2), New York City J. L. Gillson (1), Wilmington, Del. A. B. Kinzel (3), New York J. B. Morrow, (2) Pittsburgh, Pa. L. E. Elkins (3), Tulsa, Okla. * T. B. Counselman, Stamford, Conn.

Jan 1, 1953

By J. W. Downey, A. E. Dwight, M. H. Mueller, H. Knott, R. A. Conner

Sixty new ternary equiatomic compounds are reported with a hexagonal crystal structure that is isostructural with or very similar to Fe2P, D3h-P62m. HoNiAl is a typical example, with a, = 6.9893 ± 0.0003Å, C, = 3.8204 ± 0.003Å, and c/a = 0.54 7. Three holmium atoms occupy (g): x,0,1/2 three aluminum atoms occupy (f): x,0,0; one nickel atom occupies (b): 0,0,1/2; and two nickel atoms occupy (c): 4, + , 0. The nonequivalent 1(b) and 2(c) sites give rise to two sets of unequal interatornic distances (i.e., Ho-Ni and Al-NL in the case above), which account for the prevalence of Fe2P-type tertmry compounds and the scarcity of binary examples. Unit-cell constants are presented for the sixty compounds and density measurements on the compounds HoNiAl and UFeGa confirm that three formula weights are present per unit cell. Neutron and X-ray powder diffraction intensity measurements were made on CeNiAl and HoNiAl, respectively. The atomic posiLiotml parameters in CeNiAl were determined from neutron data to be x = 0.580 5 0.001 for cerium and 0.219 5 0.001 for aluminum. An investigation of the quasibinary section between the binary compounds CeNi2 and CeA12 revealed a new ternary compound CeNiAl. The compound has a hexagonal structure and is isostructural with the prototype compound Fe2P. Additional examples discovered or confirmed in this investigation provide a total of sixty ternary compounds that are isostructural with or closely related to Fe2P. Previous investigators1'2 reported the unit-cell constants for the hexagonal compounds UFeA1, UCoAl, UIrA1, ZrNiAl, ZrNiGa, HfNiAl, and HfNiGa and the present investigation has confirmed that the compounds are isostructural with Fe2P. Independently, Steeb and petzow3 reported the same structure type for UCoAl, UIrA1, and UNiA1. However, the present results suggest a different atomic site occupancy for the component atoms in the three compounds. A detailed investigation of the relative positions of the three kinds of atoms in the compounds CeNiAl and HoNiAl will be discussed. EXPERIMENTAL PROCEDURE The equiatomic alloys were prepared from elements of 99.9+ pct purity by arc melting under a helium-argon atmosphere. After homogenization at temperatures from 700" to 900' C, a metallographic examination was performed by conventional methods, and density measurements were carried out by the immersion method in CCl4. A powder sample was prepared for diffraction studies by crushing a portion of the annealed button. X-ray diffraction patterns were obtained with a Debye-Scherrer camera, in which the annealed powder was glued to a quartz filament, and indexed with the aid of a Bunn chart. Unit-cell constants were calculated from the computer program of Mueller, Heaton, and Miller4 and d spacings were obtained by the program of Mueller, Meyer, and Simonsen.5 The intensity values were calculated from the relation I, ~ (m)(L.P.)F2 by a computer program written by Busing, Martin, and Levy.6 The absorption and temperature correction factors were neglected. An X-ray study of HoNiAl was carried out to take advantage of: large differences in atomic scattering factors for holmium and aluminum, X-ray patters free of background darkening, negligible oxidation at room temperature, and negligible weight loss in the preparation of this alloy. The neutron diffraction studies were made on a powder sample of CeNiAl contained in a -in. diam V tube and a pattern was obtained with neutrons of wavelength The neutron scattering factors employed (x 10-12 cm). In contrast to the scattering amplitude for X-rays, cesium does not have the largest cross section, however, there is a sufficient difference in the neutron scattering amplitudes to distinguish between the atomic species. The neutron transmission was high, 86 pct; therefore, absorption corrections were not necessary for the cylindrical sample. Most reflections could not be observed individually, because of the relatively large unit cell (a = 6.9756 and c = 4.0206Å) and relatively short neutron wavelength; therefore, the intensity of grouped reflections was considered. The Kennicott modification7 of the Busing-Martin-Levy program6 was employed to determine the identity of the atoms at the various lattice sites and the positional parameters. RESULTS A structure for the prototype compound Fe2P was first reported by Hendricks and Kosting;8 however, the structure was in error. The correct structure, as reported by Rundqvist and Jellinek,9 is as follows. The unit-cell constants and volumes per formula weight (V/M) are given in Table I for the sixty compounds examined in this investigation and classified as Fe2P-type compounds. The structure type was determined initially from a comparison of the unit-cell constants of HoNiAl with other known examples of this structure type1' and from the density of HoNiAl, given in Table 11. The density indicated that three formula weights comprised a unit cell, as in the prototype compound Fe2P. The assignment of the three species to lattice sites was made initially on the basis of atomic size. The large holmium atoms were assigned to the 3(g) sites that have a relatively large interatomic distance to nearest neighbor positions, the small nickel

Jan 1, 1969

By J. L. Weeks

THERMAL conductivities of several samples of uranium and uranium alloys were determined using an apparatus previously described.' The value previously reported for uranium,' 0.035 cal per sec per cm per "C at 70°C, is in error due to the failure of a thermocouple during the determination on uranium. The defective thermocouple was detected after a reanalysis of the data obtained during the run and since has been replaced. Subsequently, runs on several samples of uranium show the thermal conductivity of uranium to be 0.069 cal per sec per cm per 'C at 70°C. The accuracy of the determinations was checked by measuring a sample of synthetic sapphire whose thermal conductivity was previously reported and found to be in agreement with other values."-" The values given in Table I are believed correct to % 3 pct or 0.003 cal per sec per cm per "C, whichever is larger. The samples were provided by J. H. Kittel of the Argonne National Laboratory, Metallurgy Div. References J. L. Weeks and R. L. Seifert: Apparatus for the Measurement of the Thermal Conductivity of Solids. Review of Scientific Instruments (1953) 24, pp. 1054-1057. J. L. Weeks and R. L. Seifert: Note Regarding the Thermal Conductivity of Synthetic Sapphire. Journal American Ceramic Society (1952) 35, p. 15. :' J. Francl and W. D. Kingery: Thermal Conductivity: IV, Apparatus for Determining Thermal Conductivity by a Comparative Method; Data for Pb, Al2O3, BeO, and MgO. Journal American Ceramic Society (1954) 37, No. 2, Part 11, pp. 80-84. (Part 11: special issue on thermal conductivity.) ' W. D. Kingery, J. Francl, R. L. Coble. and T. Vasilos: Thermal Conductivity: X, Data for Several Pure Oxide Materials Corrected to Zero Porosity. Journal American Ceramic Society (1954) 37, No. 2, Part II, pp. 107-110. (Part 11: special issue on thermal conductivity.) Edwin Ruh: New Jersey Ceramic Research Station, Rutgers University. Private communication.

Jan 1, 1956

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

WIENER and Bergerl reported the existence of the nitrides Fe3NiN and Fe3PtNwith a cubic L1'2 structure. The present note shows that a similar nitride Fe3PdN can be observed and that the composition range between the iron nitride Fe4N and the nitrides Fe3NiN, Fe3PdN, and Fe3PtN is occupied by single-phase cubic nitrides with structures intermediate between L1' and L1'2. The materials used in this investigation were electrolytic iron of 99.9 pct purity, carbonyl nickel of 99.7 pct purity, sponge platinum of 99.95 pct purity, and palladium sheet of 99.8 pct. purity. Binary alloys of the transition metals were induction-melted in a crucible of fused alumina, powdered, and screened to a particle size of - 200 mesh. The powders were nitrided at 600°C in a gas mixture of ammonia and hydrogen, and the crystal structure was determined with the aid of a Wilson powder camera. The results are compiled in Table I together with information from the paper of Wiener and Berger.1 The compound at the nominal composition Fe3PdN has a diffraction pattern with prominent reflections of a face-centered cubic lattice (h2 + k2+l2 = 3, 4, 8, 11, 12, 16) and weaker superstructure lines (h2 + k2 + 12 = 1, 2, 5, 6, 9, 10, 13, 14). With decreasing palladium content the superstructure lines become weaker and approach the intensity of those of Fe4N. No analysis was made of the intensities, but it can be assumed that the structure is that found by Wiener and Bergerl in Fe3NiN and Fe3PtN, namely L1'2 (perovskite structure) with both palladium and the interstitial nitrogen fully ordered. The dependence of the lattice constant upon the solute atom (Ni, Pd, Pt) content can be explained tolerably well by simple lattice expansion due to subsequent work confirms this suggestion, it will be of significance to order-disorder theory. The author is grateful to Lester Guttman for discussions on this topic.

Jan 1, 1961

By Cuppam Dasarathy

THE object of this note is to report briefly certain results of investigations on the Fe-In phase diagram. BISRA-high purity H-iron and 99.9 pct pure indium were used to prepare the alloys. The experimental techniques consisted of thermal analysis, optical metallography, and X-ray diffraction. A phase diagram based on the present results as well as those reported earlier by the author' is shown in Fig. 1. It is seen that the liquidus points fall on a smooth line which meets the monotectic isotherm at 1470°C. The liquidus extends up to 3.4 at. pct In. The phase boundary separating the two liquidus L1 and L2 is shown dotted. The experimental solidus meets the monotectic isotherm at -0.9 at. pct In. The 6/6 + L2 boundary drops steeply to the 6 + La/y + L2 boundary at -1350°C. In this region, it is impossible to detect satisfactory thermal arrests because of the steep phase boundary. The present diagram shows that indium lowers the temperature of the d/y transforma-tion and raises the temperature of the y/a transfor-mation. The y +d region is found to be very narrow. Indium gives rise to a restricted y field when alloyed with iron. The width of this field is between 0.4 and 0.5 at. pct In. Details of the alloys containing 40 and 50 at. pct In have already been reported by the author' and the transformation temperatures of these alloys are included in Fig. 1. It appeared from optical metallography and X-ray diffraction that the room temperature solubility of indium in a iron is less than 0.28 at. pct since alloys of 0.28 at. pct In and above, slow cooled to room temperature, contained dark etching second phase particles situated both in the matrix and grain boundaries of the a-grains, see Figs. 2 and 3. These particles were identified to be unalloyed indium by X-ray diffraction. The lattice parameter of the a phase reached a maximum of 2.8672A at the indium level of -0.28 at. pct. The present diagram, Fig. 1, is in substantial agreement with that of Stadelmaier and Fiedler' except for certain differences in detail. For example, they found the monotectic composition and temperature to be 7.0 at. pct In and 1443oC, respectively, while the present work indicates them to be 3.4 at. pct In and 1470°C. The 6 + L2/y + L2 transformation is indicated in the present work to occur at -1350°C, whereas Stadelmaier and Fiedler find this to occur at -1320°C. They also claim that the width of the y field is 0.2 at. pct In while the present work shows the width to be between 0.4 and 0.5 at. pct In. 1) Indium, when alloyed with iron, gives rise to a restricted y field, the width being >0.5 at. pct In.

Jan 1, 1970

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who called at Institute headquarters during the period June 10, 1916 to July 10, 1916: Arthur Adams, Miami, Ariz. John M. Lovejoy, New Rochelle, N. Y. J. H. Batcheller, Mattapoisitt, Mass. J. F. Manning, Seoul, Korea. R. S. Bonsib, Low Moor, Va. E. P. Mathewson, Anaconda, Mont. E. L. Booth, New York, N. Y. Edwin W. Mills, Seoul, Korea. C. L. Bryden, Scranton, Pa. Arthur Notman, Bisbee, Ariz. F. Crabtree, Pittsburgh, Pa. L. B. Reifsneider, Daiquiri, Cuba. L. B. Eames, Pueblo, Colo. W. S. Schuyler, Berkeley, Cal. S. J. Gormly, Guayacan, Chile. 0. N. Scott, Toronto, Ont., Canada. Ernest A. Hersam, Berkeley, Cal. Arthur F. Taggart, New Haven, Conn. A. W. Hudson, Douglas, Aria. Warren D. Thompson, Boston, Mass. Chas. W. Johnston, West Norfolk, Va. Thor. Warner, IGngman, Ariz. Rodolphe L. Agassiz has been chosen president of the Calumet & Hecla Mining Co., an office which has been vacant for over a year. Percy E. Barbour, Managing Editor of the Engineering and Mining Journal, resigned his commission as 2d Lieutenant in the Main Coast.

Jan 8, 1916

By J. Alfred Berger, O. M. Katz

Selected samples of hydrided Zr-Hf alloys were rapidly quenched to voom temperature and exrtrnined metallographically, by X-ray diffraction, and through micro hardness studies to confirm high-temperutuve data Confirming experiments sllowed that there were five phases in this Lernary system: 1) hextrgonal with lattice parameters similar to that of the initia1 Zr-Hf alloy but slightly enlarged due to dissolved hydrogen; 2) fee with properties of a brittle, intermediate, hydride compound; 3) fct with c/a crvoltnd 1.07 and which appeared as a neetilelike precipitale; 4) hexagonal, designated ?, with c/a ratio of 2.37; and 5) orthorhombic, designated X, with a = 4.67, b = 4.49, and c = 5.093 and whose tnicro-st?ruct~ival nppetrl-nnce depcncled o/i, heat lvecrt~r~ent. The tetragonrrl phase never crppeal-erl witkorct the cubic hydricle. Abpecrrtrnce of 0 and A also tlependet on the hafnium content of the zirconium. A previous paper' on the Zr-Hf-H system described the thermochemical data obtained with a high-vacuum, high-sensitivity mirrogravimetric apparatus. This data presented a fairly complete picture of the phase relationships at elevated temperatures. However, it could not establish the actual crystal structures, lattice parameters, or metallographic disposition of the hydride phases. The present complementary study utilizes X-ray powder patterns along with light and electron microscopy to characterize completely the five hydrided phases found in Zr-Hf-H alloys quenched to room temperature. Crystallographic features of the zr-Hf,2,4 zr-H,5-7 and Hf-H8 systems have been summarized in Table I. Designations of a, ß, and ? were retained in the Zr-Hf-H system for the phase regions through which the pressure-composition isotherms always sloped. However, it was not firmly agreed that these were single-phase regions.' In fact, the region designated y always contained a cubic as well as a tetragonal phase after quenching to -196°C. MATERIALS Preparation of the high-purity Zr-Hf alloys has been described.' The four zirconium alloys which were hydrided contained 37 wt pct Hf (23 at. pct), 51 wt pct Hf (37 at. pct), 73 wt pct Hf (58 at. pct), and 91 wt pct Hf (82 at. pct), respectively. These were designated B-2, B-4, B-6, and B-8. Photomicrographs of the initial alloys showed the material to be quite clean as would be expected from the precautions exercised in producing them. However, there were a number of annealing twins but no other subgrain structure. In addition to the four original alloys, fifteen hydrided samples were observed at room temperature. Hydrogen compositions are given at the top of Tables I1 to V. APPARATUS The phases present at elevated temperatures were studied by quenching hydrided samples to room temperature by two different methods, both under vacuum: 1) fast cooling of the sample tubes of the microgravimetric apparatus1'9 with flowing air and 2) rapid quenching into liquid nitrogen. The cooling rate for 1) was 750° to 250°C in 30 sec. Since the microbalance chamber was not designed to permit very rapid cooling of a hydride sample, all liquid-nitrogen quenching was done in an auxiliary experiment. The auxiliary quenching apparatus consisted of a small-bore, high-temperature furnace, a sealed SiO2 tube containing the sample, and a dewar quenching flask filled with liquid nitrogen. The hydrided sample, previously quenched in the microgravimetric reaction chamber, was placed in a platinum boat in a vacuum-degassed SiO2 tube. A zirconium wire getter and degassed SiO2 rod, to reduce the internal volume, were also in the tube. After sealing the tube under vacuum the zirconium getter was heated to absorb the last traces of gas. Only the sample was heated at the reaction temperature for the desired length of time, and then the tube dropped through the opposite end of the furnace into the dewar. A quenching rate of 200" to 400° C per sec was estimated. Analyses of samples after the auxiliary experiment also showed practically no increase in oxygen or nitrogen content from heating in the SiO2 tube. All of the samples were examined at room temperature by the X-ray powder method. The majority of the powder patterns were obtained with double nickel-filtered CuKa radiation after 8- and 16-hr exposures in an 11.48-cm-diam camera. Cobalt and chromium radiation were also used to spread out the high d value end of the Pattern. Such patterns readily identified the minor phases. NO oxide or nitride lines were found. Where sharp back-reflection lines existed it was possible to reduce the

Jan 1, 1965

By J. A. Snyder, W. L. Finlay

G. Edmunds—Solid solubility is considered to be of either the interstitial or the substitutional type. Is it possible, in a binary alloy as the simplest case, that some of the solute atoms are present in the normal lattice sites (substitutionally or filling lattice vacancies) while simultaneously others are in interstitial positionss One might even ask whether a distribution of the two types may be the normal situation. H. M. Meyer—Metastable states of interstitial atoms occupying vacant lattice sites possibly occur as well as of substitutional atoms squeezed in between regular matrix positions. However (as we know since Hume-Rothery), the solute atoms choose between the two kinds of solutions; consequently, every solute will be unequivocally either substitutional or interstitial in the equilibrium state of the solid solution. M. Balicki—In view of the fact that the authors apparently correlate the analysis of the alloys at the ingot stage with the properties exhibited at the testing stage, I would like to ask whether this is a fully justifiable procedure. In other words, how good are their determinations of solute concentration for correlating them with the mechanical properties. The answer to this question may explain some of the divergencies. Assuming good enough homogenization of the samples and exact determination of mechanical properties the position of the plotted experimental points will depend solely upon the accuracy of composition determination. If this is not accurate, say due to loss or pickup of elements during processing from the ingot to the testing stage, or due to a systematic error in the method employed for obtaining solute concentration data, the points will deviate from their true position and may align themselves along a different curve than the one expected. H. V. Kinsey—We have been studying the creep-rupture properties of titanium-base alloys at 1000°F. In the course of this work, anomalies in behavior of the alloys that would suggest that the material under test was becoming stronger as the test progressed have been observed. If this was so, the most likely explanation that we could think of was that the test bars were absorbing oxygen and nitrogen from the air during the test and were thereby becoming strengthened. In an attempt to determine the strengthening effect of absorbed oxygen and nitrogen the following experiment was conducted. A length of cold-rolled titanium was supplied by the E. I. du Pont Co. Two test bars, having a 1/4 in. diam gauge length, were prepared from this material. One bar was tested in the as-received condition. The second bar was heated in air at 1550°F for 100 hr and subsequently air cooled prior to testing. A testing temperature of 1000°F was employed. The results of these tests are tabulated in table 11. In the author's opinion, is it reasonable to assume that the bar that was exposed to air at 1550°F for 100 hr was stronger because it absorbed oxygen and nitrogen from the air during this heat treatment? W. L. Finlay (authors' reply)—Direct experimental evidence for or against Mr. Edmunds' interesting suggestion will probably never be available. It seems possible, however, that mixed interstitial-substitutional solid solution might well occur with interstitial elements. The less likely possibility of interstitial solution of a normally substitutional element like copper in aluminum was recently discussed at length by the

Jan 1, 1951

Cyanidation and Concentration of Gold and Silver Ores. By J. V. N. Dorr and Francis L. Bosqui. Second edition, completely revised. Mc-Graw-Hill Book Co., New York. $8.50.-First issued 13 years ago, this book has become a milestone in the literature of mining and metallurgy. Mr. Dorr, with the assistance of F. L. Bosqui, has completely revised the book. Its comprehensive picture of ore dressing and hydrometallurgical methods are of importance to mining engineers and operators throughout the entire field. Operating data and methods, flowsheets, testing procedures, and many miscellaneous methods of extracting bullion are given. The book is divided into two sections, the first discussing principal unit processes involved in gold and silver recovery, and the second describing with flow diagrams a number of typical treatment plants selected from the more important gold and silver mining areas in various parts of the world. International Conference on Coal Preparation in Paris. English Language edition of transactions.-The transactions of the recent conference in Paris will be presented in the form of 6 issues of the revue de l'Industrie Minerale, and may be purchased for 3000 francs per set. About 60 papers were presented at the meeting, covering a wide range of interesting subjects. Ad- dress subscriptions to: Secretariat de la Societe de l'Industrie Minerale, 19 rue du Grand-Moulin, Saint-Etienne (Loire) France.

Jan 1, 1951

By John G. Hall

The pumping operations at the Chief mine have been unique in the respect that for many years the entire flow of water into the mine has been disposed of by pumping into natural underground "caverns" or "sinks." Volumes up to 4000 gpm have been pumped into these caverns with no apparent tendency for the caverns to fill with water, and it has never been proven that any of the water returns to the mine workings. Major pumping operations have been carried on during two periods, the first from 1918 to 1927, and the second from 1942 to the present time. Early Pumping Operations CHIEF MINE The Chief Consolidated Mining Co. was organized in 1909, and for the following nine years ore was developed and mined from the 600 level down to the 1800 level, all above the permanent water table, the 1820 level. The ore occurs as extremely-irregular pipes of replacement ore in limestone, and to date a total of approximately 2 1/2 million tons of ore has been produced. The ore was highly oxidized down to the permanent water level, and some highly-oxidized ore runs occur beneath the permanent water table. In 1916, with extensive mining being done on the 1800 level, 20 ft above the water table, there were indications that a zone of secondary enrichment might exist below the water, and in order to follow the ore runs to greater depth, it was realized that arrangements would have to be Made to pump water to the surface. The original pumping installation was designed to pump 350 gpm in five stages against a 1900-ft head to the surface. By January 1919, the water had been lowered to the 1900 level and an excellent grade of silver-lead ore was being produced from the zone of secondary enrichment. At this point. the flow of water equalled the capacity of the pumps, and pumps of an additional 1000 gpln were installed to supplement the original system. By January 1920, the water had been lowered approximately 100 ft, and the total flow of water was 1000 gpm. The water was being pumped from many different places in the mine where ore was being followed downward, with 27 different pumps operating below the 1800 level, mainly Cameron air-driven sinker pumps. These first sinking pumps were cumbersome and inefficient, and each of the larger pumps weighed approximately three tons and required tremeridous volumes of compressed air. During this period, an exploration drift being extended north and west from the Chief shaft on the 1600 level encountered a large natural cavern some 2000 ft from the shaft. This cavern in places measured 60 ft in diameter. Sometime later the disposing of water into this cavern was suggested, and as an experiment to determine the results of such an operation, an attempt was Made to fill the cavern by pumping in a small volume of water, but the water disappeared as fast as it was discharged into the cavern. It was decided then to try the cavern as a drainage outlet for the entire volume of water being pumped to the surface, and the water apparently did not return to the mine workings. Subsequently water up to 3000 gpm was pumped into this cavern. An attempt was made to determine whether any water was being returned from the cavern to the lower workings, and 100 lb of sodium fluorescein salt was added to the water discharged into the cavern, but no trace of it was found in the drainage water in the mine. Results of another such test will be described later.

Jan 1, 1950

Societies, Boards, Etc , on Which Institute Has Representation United Engineering Society WILLIAM L SAUNDERS, President GEORGE H PEGRAM, 1st Vice-president ALFRED D FLINN, Secretary J V W REYNDERS, 2d Vice-president JACOB S LANGTHORN, Treasurer HENRY A LARDNER, Assistant Treasurer Finance Committee GEORGE H PEGRAM Chairman J VIPOND DAVIES BANCROFT GHERARDI W F M GOSS WILLIAM L SAUNDERS, ex-officio House Committee ALFRED D FLINN, Chairman FREDERICK F SHARPLESS' GEORGE T SEABURYO F L HUTCHINSON CALVIN W RICE

Jan 1, 1923

By D. Atkinson, C. Bodsworth, I. M. Davidson

A geometric model of interstitial solid solutions, which has been used previously as a basis for the prediction of carbon activities in Fe-C austenite, is shown to serve also for the calculation of nitrogen activities in Fe-N austenite. The model has been developed to enable predictions to be made of the activities of an interstitial element in the presence of two host atom species. The activities calculated via the model are shown to be in satisfactory agreement with the measured values in the austenite phase for carbon in Fe-C-Co, Fe-C-Cr, Fe-C-Ni, Fe-C-~n, Fe-C-Si, and Fe-C-V alloys and for nitrogen in Fe-N-Ni alloys. The effect of the second substitu-tional solute on the logarithm of the activity of the interstitial element is expressed as the product of a constant mad the atomic concentration of that solute. The constants so derived we related to the thermo-dynamic interaction coefficients which describe the effect on the activity coefficient of carbon of an added solute element. In recent years the thermodynamic activities of carbon and nitrogen in the single-phase austenite field have been determined for iron binary alloys and for several iron-base ternary alloys. In order to extend the use of these measurements, it is desirable to be able to predict with reasonable accuracy the activities of the interstitials at compositions and temperatures other than those which have been measured experimentally. In all the systems studied to date, the interstitial elements do not conform to ideal behavior. Hence, the available data cannot be extrapolated or interpolated using the simple thermodynamic concepts of solutions. Several models have, therefore, been formulated for the purpose of predicting the activity of an interstitial element in the presence of one species of host atom. These models can be divided into the geometric1"5 and energetic6-' types. The former group is based on the assumption that at low concentrations the activity of the interstitial species is determined by a composition-dependent configurational entropy term and an excess free-energy term which is temperature-dependent but independent of composition. The purpose of this paper is to show that the treatment, based on a geometric model, can be extended to enable predictions to be made of interstitial activities in the presence of two substitutional host atom species. THE CONFIGURATIONAL ENTROPY OF MIXING ICaufman5 has shown that the configurational entropy, S,, for a binary solution comprising of a host atom species, A, and an interstitial species, I, can be expressed as: where NI is the atom fraction of the interstitial species, R is the gas constant, and (2 - 1) is the number of interstitial sites excluded from occupancy by the strain field around each added interstitial atom. The number of interstitial sites per host atom, p, is unityg for the fcc austenite solutions considered here. The configurational entropy of mixing for a ternary solution comprising two substitutional atom species, A and B, and one interstitial species, I, can be derived similarly. Let the number of atoms per mole of each of these species in the solution be represented by «a, ng, and nI. From geometric considerations, it is improbable that the addition of a few atom percent of a second host atom species will change the type of sites (i.e., octahedral) in which the interstitial atom can be accommodated in the austenite lattice. At higher concentrations (determined largely by the relative atomic radii of the atomic species present and any tendency to nonrandom occupancy of the host lattice sites) other types of interstitial sites may become energetically favorable. Restricting consideration to compositions below this limit, for 1 = 1 the number of suitable interstitial sites is given by (n + nB). However, if each interstitial atom excludes from occupancy (Z - 1) additional sites, the total number of sites available for occupation is reduced to (n + ng)/Z. The number of vacant interstitial sites is given by: The total number of recognizable permutations of the atoms must include the recognizable, different configurations of the A and B atoms on the host lattice. Assuming that these arrangements are purely random, and are not affected by the presence of the interstitial species, the total number of recognizable permutations in the ternary alloy is given by: The configurational entropy is obtained by expanding, using Stirling's approximation, and collecting like items, as:

Jan 1, 1969