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(Members are urged 'to, send in for this column any notes of interest concerning themselves or, their fellow-members.) Members and guests who registered at Institute headquarters during the period Sept. 10 to Oct. 10, 1915: George H. Blakemore, Sydney, N. S. W. W. B. A. Dingwall, San Antonio, Tex.. H. Haege, Sydney, N. S. W. R. H. Jeffrey, London, England. C. A. Filteau, New York, N. Y. H. S. Emlaw, Spring Lake, Mich. Myron R. Walker, Cerro de Pasco, Peru. Y. T. Woo,' Tientsin, China. William R. Grunow, Morenci, Ariz. A. L. DeDeken, LouVain, Belgium. E. DeGolyer, Norman, Okla. K. P. Swensen, Tokyo, Japan. William W. Elmer, Tuttletown, Cal. Charles Enzian, Wilkes-Barre, Pa. Huntington Adams, Iquique, Chile. C. F. Schnepp, Cobalt, Ont., Canada. W. Ray Cox, for several years Mineral Inspector of the General Land Office at Portland, Ore., has been appointed Professor of Mining and Metallurgy in the School of Mines, Oregon Agricultural College, Corvallis, Ore.

Jan 11, 1915

E. O?C. Acker Jinzoc Adachi Truman H. Aldrich Walter H. Aldridge Anson W. Allen John H. Allen William R. Appleby W. Lawrence Austin W. S. Ayres David Baker John Henry Banks Henry C. Banon Alonzo F. Bardwell Wm de L. Benedict Robert Bentley Andrew A Blair Walter M. Brodie Elwin F. Brown Fredrick Burbidge H.H. Burden Charles Butters

Jan 1, 1942

By R. B. Woodworth

In the sinking of bore holes, there are but two fundamental operations —drilling and hoisting—which determine in the main the character of drilling mechanism and structures. There are endless ramifications, however, in the execution of these fundamental operations, according to the purposes for which the bore holes are drilled, their maintenance after completion, the protection and convenience of workmen, etc. The three main lines of use for bore holes are in mineral exploration, the sinking of water and salt wells, and the exploitation of pqtroleum and natural gas. This paper has to do more especially with the last. Here again there are many divergences. Wells may be drilled by either the percussive, the hydraulic, or the abrasive method. Finally, each of these methods, as applied by drillers of diverse nationalities, has followed somewhat different lines of development. The American system of cable-tool drilling has perhaps had the widest application; the hydraulic rotary is also in extensive use; but the Canadian system, the Galician system, and the Russian free-fall system all have their points of recognized merit and are preferred by operators accustomed to their use. These differences in drilling procedure, which rest ultimately on essential variations in geological conditions, are reflected in the drilling structures as well as in the drilling mechanism. The purpose of the present paper is to record those stages in the development of the application of steel to the construction of drilling mechanism and structures with which the writer has been intimately associated, and to contribute to the history of the art of drilling other data acquired in the course of his personal investigations. It is necessarily limited by reason of space to American practice, with especial reference, therefore, to the cable-tool system and the hydraulic rotary method of drilling wells for oil and gas.

Jan 1, 1916

By E. F. Jr. Young, H. E. Steinman, G. C. Smith

Through a progressive laboratory and pilot-plant program Jones & Laughlin Steel Corp has analyzed and corrected mine drainage pollution problems at all of its coal mines. In conducting this program, the company found no "typical" drainage discharge. Each discharge point at each mine was unique, so that varied approaches were needed to eliminate stream pollution. To illustrate the variety of these approaches, the treatment of drainage from foul, discharge points at three mines in Pennsylvania will be considered here. The flows and critical analyses of the drainage sources and treated effluents arc shown in Table I. Hydrated Lime Works at Thompson Borehole The discharge stream from the Thompson bore- hole at the Vesta No. 5 mine flowed into a small branch creek where it created a "yellowboy" deposit and affected aquatic life. Investigation indicated that hydrated lime would neutralize the acid and precipitate ferric iron without aeration. Treatment of the 150.000-gpd flow, however, created about 4000 gpd of wet sludge for which there was no nearby accumulation site. With State approval, this sludge was deposited through an unused borehole into an abandoned section of the Vesta No. 6 mine several miles away.

Jan 1, 1970

The following is an incomplete list of members and guests who called at Institute headquarters during the period Oct. 10, 1918 to Nov. 10, 1918. J. Carson Adkerson, Virginia. George H. Parsons, Hayden, Ariz. Andrew B. Armstrong, Connecticut. W. E. Pomeroy, New York. Courtenay DeKalb, San Francisco. Ezra C. Rider, Bisbee, Ariz. Clifford G. Dennis, San Francisco. H. W. Seaman, Chicago, Ill. Rudolph Emmel, Boston, Mass. William Allen Smith, Northampton. Emil Gathmann, Baltimore Md. R. K. Stockwell, Salt Lake City, Utah. Ernest S. Geary, Denver, Colo. W. G. Swart, Duluth, Minn. W. E. Hopper, Washington, D. C. Kirby Thomas, New York. W. Spencer Hutchinson, Boston, Mass. - Warren D. Thompson, Harvard Club. E. W. Kohl, Jr., Philadelphia, Pa. H. Vincent Wallace, Los Angeles, Cal. E. C. Nighman, Butte, Mont. Paul T. Benson, formerly with the Tacoma smelter, has resigned his position there to accept one with the Great Metals Mining and Milling Co. at Nespelem, Wash. Prof. Edward E. Bugbee, of the Mining Department of the Massachusetts Institute of Technology, has been granted a leave of absence to accept the position of Assistant Director of Education for the S.A.T.C. of five southern states with headquarters at Raleigh, N. C.

Jan 12, 1918

By S. J. Noesen, J. R. Hughes

Several four-inch-diameter tungsten ingots were arc melted in vacuum or in hydrogen atmospheres. Melting pressures, melt-off rates, effect of atmospheres, and other pertinent factors were examined. Two of these ingots were extruded at 1650°C. Subsequently, forging and rolling were carried out at lower temperatures. For a 60 per cent area reduction by rolling, a one-hour recrystallization temperature of 1250°C was obtained. This temperature is considerably lower than those reported in previously published work, and can probably be attributed to the extreme purity of the as-cast ingots (N, H, 0 all less than 1 ppm). EVER since W. D. Coolidge, in 1909, described his process for producing tungsten metal of high density and good workability via the powder metallurgy tech-

Jan 1, 1961

By R. J. Cowan

In the art of cementation a controversy has been going on for years as to whether solid or gaseous carbon is the active agent in carburizing steel. More recently opinion has crystallized into a compromise to the effect that carburizing is a gaseous cementation of steel in the presence of solid carbon. The importance of this theory has a particular bearing upon the work to be described. In the art of carburizing, use is commonly made of such words as '' Catalytic" "atomic," "nascent" and "activated," in an attempt to describe the process. These words are used indiscriminately. For instance, the gas is said to be "catalytic" and carbon to be "nascent," or vice versa. In using these expressions, investigators are confirming the acceptance in their minds of the active conditions of both gas and carbon in the cementation process. Reactions at Metal Surfaces For many years attention has been directed to the consideration of reactions that occur on metal surfaces. When heated under the influence of certain metals a complex gas will be broken down and one of the constituents thereof usually found to be very active chemically in combining with the metal. The process of nitriding is an example of this type of reaction. In this case ammonia (NH3) breaks down at the metal surface and the nitrogen which is thus liberated reacts with the surface to form a nitride whereas molecular nitrogen not so liberated is inert and will not react chemically with the metal. Whatever term or terms may be used to describe such reactions, the fact remains that they are highly important and valuable in their commercial applications. Since the metal surface plays so important a part in these reactions, it is evident that any accumulation of reaction products thereon interferes seriously with the progress of the reactions. For this reason it is desirable to remove all such products as rapidly as they are formed in order to bring active gas into contact with the surface and thus facilitate the desired reactions. This is accomplished best by conducting the operation in a continuous manner, thereby causing the reacting gases to pass over the

Jan 1, 1931

By H. Foster Bain

The recent admirable paper on the general subject of coalcutting machines presented to the Institute by Mr. E. W. Parker* leaves but little to be desired so far as the well-proven and widely-used machines are concerned. The general character of the machines in use and the range of their adaptabilities have been very well stated. It will be noted that in all cases these machines are being used in room-and-pillar work, and indeed (though attention was not directed especially by Mr. Parker to that point) they are practically confined to that work. It is probable that neither the chain breast- nor the pick-machine is, or can be, used to any great advantage in long-wall work.

Jan 1, 1900

By J. R. Campbell

A DOZEN years or so ago, the general superintendent of our company, now the president, Mr. W. H. Clingerman, detailed me to make a study of the coal-washing problem and collect data, which threw me into contact with the best washery men of the country. and took me to those districts where the washing of coal for metallurgical purposes is carried out. I investigated many kinds of coal-cleaning schemes, made numerous tests on them, and collected voluminous data, yet I confess frankly that I have had but little practical washery experience and that little has been at the Middlefork washery of the United States Fuel Co. at Benton, Franklin Co., Ill., which was put in operation last fall. While this wash-cry installation may not be the "last word," I am quite sure it embodies some long steps in advance over older designs and constructions. From the washery man's standpoint, the removal of pyrites, or marcasite, a disulfide of iron, is the one vital problem, and the one productive of the most beneficial results, so far as elimination of sulfur is concerned. Sulfates and so-called organic sulfur occupy quite a secondary -position and are generally lost sight of in coal washing: The elimination of sulfur in coal in the past has usually been accomplished by jigging in water, but lately the use of concentrating tables has been employed with good success, and some mention may be made of the flotation process on fine coal, though hardly considered practicable. Coal washing, is rapidly coming into its own, due to the depletion of low-sulfur coals for coking purposes, and before many years we predict as careful attention being given to the design and construction of coal washeries, ,as is now being given to byproduct plants and other allied industries. Heretofore, coal washing has been considered only as an incidental and a necessary evil-instead of the big problem it is one worthy of the most careful study by men well trained along technical lines and capable of delving into the fundamental principles.

Jan 9, 1919

By C. K. Leith

CERTAIN ideas on iron and steel sanctions to follow originated in a series of conferences held under the joint auspices of the War Department and Brookings Institute in Washington last spring. The views presented may be regarded as those of substantial segments of the steel industry. In view of the fact that steelmaking capacity can be so quickly converted to the production of armament, any effective control must necessarily include the entire steel industry and not solely the parts devoted to the production of implements of war. It must also be exercised all the way from production and shipment of raw materials through their ultimate conversion into finished products and use. Control will be dis- cussed under two main headings: (I) control of raw materials at the source; (2) control of steel capacity within the Axis countries.

Jan 1, 1944

Discussion of the paper of W. R. SHIMER, presented at the New York meeting, February, 1915, and printed in Bulletin No. 99, March, 1915, pp. 557 to. 585. WILLIAM R. WEBSTER, Philadelphia, Pa.-I would like to ask Mr. Shimer how the finishing temperature of the H-beams and other beams rolled on the Gray mill at Bethlehem compare with the rolling temperatures of the rails referred to in this paper. Also, how the reductions in the rolling of the beams compare with the reductions in the rolling of the rails. I would also like to know if any drop tests were' made on the rails referred to as having been allowed to cool and then annealed; in other words, what results, if any, were obtained from tests on rails after the internal strains of rolling had been removed; and in the matter of the rail blooms, I would like to ask if they are not often heated to a higher temperature than is desirable on account of the thin flanges in order to carry the heat through to the finishing pass. The tensile strength of the steel in these rails is given as 125,000 lb. per square inch, which is almost as high as tire steel. If some of these blooms were rolled into rounds of about the same section as the head of the rail, would you not get better results from tension tests than those from the head of the rail? In other words, in rolling rounds, whether you would not be able to control the rolling and finishing temperatures better than is possible in the rail, owing to thin section of the rail flanges. Some years ago I had experience with the rolling temperatures of tire steel, running from about 127,000 to 133,000 tensile strength. These tires had the tensile strength and the deflection specified. One of the manufacturers had no trouble whatever, after a little experimenting, in meeting the conditions of the specification. Another manufacturer who made some of these tires came to the office and stated that he had tried tires from three heats of steel and could not meet the specifications and

Jan 5, 1915

By Samuel G. Lasky

In a recent discussion of the mineral resource position of the United States, published in the September 1946 issue of Mining and Metallurgy, I expressed my conviction that ore deposits of major magnitude remain to be found in this country and that they can be found without undue cost or risk. I stated with equally strong conviction, however, that if the search for such deposits is to be notably successful there must be, among other things, a reorientation of philosophy and mental habits on the part of many who would be connected with the search. I would now like to enlarge upon that statement. For such a purpose. we may consider that the search for concealed deposits involves four steps: (I) the selection of areas for further study; (2) the geologic study of those areas in order to verify their general favorableness and in order to choose specific patches worthy of being tested; (3) the decision whether exploration of the patches chosen should actually be undertaken; and (4) the exploration itself. The first two steps and the last rest upon the judgment and skill of geologists. The third step—the decision whether exploration should be undertaken—rests upon management. In my opinion, the philosophies or principles that have guided these steps in the past are now inadequate. Philosophy of Appraisal If concealed deposits are to be looked for, how are the places of their possible concealment to be recognized? Every known mineralized area still in the prospect stage has already been repeatedly examined and condemned. As for those deposits concealed under later rocks, there may be not even the clue of a near-by outcrop for engineer or geologist to consider. flow then, are we to know where to look? Geologic Probability In the early days of our mining industry, ore deposits were found mainly by "following the ore." Later, as such opportunities decreased, and as geologic concepts became accepted, deposits were found more and more through use of the notion of geologic probability. Many instances can be cited wherein a courageous operator ignored the implications of the unsuccessful efforts of predecessors and, solely by "following the ore," converted a discredited prospect into a good mine. Similar experience doubtless will occur in the future, but "following the ore" will no longer in itself find new deposits in the amount needed. Nor can enough new ore be expected from further use of the notion of geologic probability, for, as mentioned above, our known prospects have already been ex-

Jan 1, 1949

By Samuel G. Lasky

In a recent discussion of the mineral resource position of the United States, published in the September 1946 issue of Mining and Metallurgy, I expressed my conviction that ore deposits of major magnitude remain to be found in this country and that they can be found without undue cost or risk. I stated with equally strong conviction, however, that if the search for such deposits is to be notably successful there must be, among other things, a reorientation of philosophy and mental habits on the part of many who would be connected with the search. I would now like to enlarge upon that statement. For such a purpose. we may consider that the search for concealed deposits involves four steps: (I) the selection of areas for further study; (2) the geologic study of those areas in order to verify their general favorableness and in order to choose specific patches worthy of being tested; (3) the decision whether exploration of the patches chosen should actually be undertaken; and (4) the exploration itself. The first two steps and the last rest upon the judgment and skill of geologists. The third step—the decision whether exploration should be undertaken—rests upon management. In my opinion, the philosophies or principles that have guided these steps in the past are now inadequate. Philosophy of Appraisal If concealed deposits are to be looked for, how are the places of their possible concealment to be recognized? Every known mineralized area still in the prospect stage has already been repeatedly examined and condemned. As for those deposits concealed under later rocks, there may be not even the clue of a near-by outcrop for engineer or geologist to consider. flow then, are we to know where to look? Geologic Probability In the early days of our mining industry, ore deposits were found mainly by "following the ore." Later, as such opportunities decreased, and as geologic concepts became accepted, deposits were found more and more through use of the notion of geologic probability. Many instances can be cited wherein a courageous operator ignored the implications of the unsuccessful efforts of predecessors and, solely by "following the ore," converted a discredited prospect into a good mine. Similar experience doubtless will occur in the future, but "following the ore" will no longer in itself find new deposits in the amount needed. Nor can enough new ore be expected from further use of the notion of geologic probability, for, as mentioned above, our known prospects have already been ex-

Jan 1, 1949

By W. F. Hosford, E. W. Kelley

Deformation studies have been conducted at room temperature on single crystals of magnesium and magnesium alloys with thorium and with lithium. Single crystals oriented to suppress shear on the easily activated basal slip systems were deformed by plane-strain compression. Compression along the C axis was accommodated by {1011} banding. Compression perpendicular to the unconstrained c axis activated {1012} twinning, and, after virtually complete twinning, deformation continued by {1011) banding in the twinned material. Compression perpendicular to the constrained c axis was accommodated by the simultaneous operation of (1012) twinning against the constraint and (1011 ) banding. Although this orientation was favorable for {1010)(1210) prism and {1011}(1~10) pyramidal slip, these modes were not observed in pure magnesium or in Mg-0.5 pct Th. However, {10i0)(1~10) prism slip was observed in crystals of Mg-4 pct Li during compression perpendicular to the constrained c axis. Fracture in all materials occurred parallel to (1124) or {l~il) depending on the orientation and composition of the specimen. THE mechanical behavior of the hcp metals is strongly anisotropic. Although several slip systems have been reported the slip is cpmmonly in the directions of closest packing, the (1210),' and this does not produce strains parallel to the c axis. Hence the inherent anisotropy. The deformation mode most easily activated in magnesium at room temperature is (0001)(1210)- basal slip. Also {1010}(1~10) prism slip and {1011)(1210) pyramidal slip have been reported, primarily at elevated temperatures.2"4 However, at room temperature the shear stresses to activate the prism and pyramidal modes are roughly a hundredfold greater than that required for basal slip.'j4 Thus prism and pyramidal slip may be expected only under special conditions of loading. Strains normal to the basal plane can be produced by twinning, however. Many twinning modes have been reported for magnesium,' with (1012) twinning the most common and relatively easy to activate. Magnesium can deform by (1012) twinning when stressed along the c axis jn tension, but not in compression. In contrast, (1011) twinning is activated by compression along the c axis and not by tension. In addition to primary twinning, secondary twinning or slip can occur within the reoriented material of primary twins.' In general at least five independent shear systems must be active to bring about an arbitrary shape change such as that in the individual grains of a deforming polycrystalline material.' Because basal slip can_ provide only two independent shear systems and (1012) twinning can only accommodate an extension of the c axis, other deformation modes must be active in magnesium for an arbitrary shape change to occur. The purpose of this investigation has therefore been to study the various deformation modes in magnesium at room temperature, with special emphasis on those modes that are less easily activated. The effect of the alloying elements, thorium and lithium, has also been investigated. In polycrystalline aggregates, unambiguous identification of deformation modes is extremely difficult and the direct evaluation of the resolved shear stresses to activate them is not feasible. On the other hand, uni-axial tension and compression experiments on single crystals may not activate some of the- deformation modes because basal slip and/or {1012) twinning cannot be suppressed in most orientations. However, it should be possible to activate all possible deformation modes using oriented single crystals and plane-strain compression. Identification of active deformation systems and evaluation of the resolved shear stresses required to activate them should be facilitated. Wonsiewicz and Backofen have recently completed an investigation of the plasticity of pure magnesium crystals at various temperatures utilizing plane-strain compression and selected crystal orientations. This technique has also been used in the present work. The seven orientations selected for study are indicated in Table I. Plane-strain compression along the c axis (orientations A and B) should activate some deformation mode _other than basal, prism, or pyramidal slip, or (1012) twinning. In orientations C and D, prism or pyramidal slip would be expected to take place. When the compressive load is applied perpendicular to an unconstrained c axis (orientations E and F) the three slip modes should be suppressed but not (10i2) twinning. In orientation G, basal slip should occur.

Jan 1, 1969

R. W. NEWCOMB, New York, N. Y. (written discussion*).-0n page 1712, the middle paragraph states that, in industrial equipment, only the single-step method of automatic regulation has been applied. Quite recently, there has been developed an automatic temperature regulator, operating in conjunction with a pyrometer of the thermoelectric type, in which the control is a slow regulation, with a range capable of regulat-ing valves, dampers, rheostats, or any other rotatable member, through one or more complete revolutions. It can control two valves at the same time, with a fixed definite ratio between them. Aside from those conditions in which it is. necessary to control two valves with a definite ratio one to the other, the greatest advantage that this slow, even control will have over those controls that are either all on or all off, will be for use in connection with processes where a large temperature variation is required, extended over a considerable period of time; that is, where the temperature must be regulated along an in-creasing or decreasing time-temperature curve.

Jan 12, 1919

By M. T. Simnad, C. E. Birchenall, M. H. Davies

THE marker movements observed by Davies, Simnad, and Birchenall during the growth of magnetite on wustite have been misinterpreted. It is the purpose of this note to correct the original interpretation. In that investigation wustite specimens were prepared by oxidizing pure iron disks in water vapor until the iron was consumed. Argon was used as a carrier gas for the water vapor and on the complete conversion of the metal to its oxides ('FeO' plus a small amount (10 pct) of surface Fe3O) the water supply was bypassed and the specimens were annealed in argon alone in order to equilibrate the wustite with the overlying magnetite. After cooling, the magnetite was ground off, a crude magnetic test being employed to determine its complete removal. Radioactive silver streaks were then applied to the surface and the specimen was oxidized completely in water vapor to prevent hematite formation. After complete oxidation the markers were found to enclose about 80 pct of the magnetite with the other 20 pct lying outside the markers. This observation was interpreted to mean that oxygen transport was four times as great as iron transport during the growth of the magnetite. The conclusion would have been correct if, as in the case of wustite growing on iron, all the iron had started from one side of the marker and all the oxygen from the other side initially. Actually a material balance is required. For simplicity, take wustite to be exactly FeO, and magnetite to be Fe3O,. Then at the start of the reaction 3 FeO + O -> Fe,O., All of the iron and three-fourths of the oxygen of the final product will be within the marker inter- faces. The other fourth of the oxygen is in the gas phase outside the marker. From the experimentally determined final position of the markers simple calculation shows that one-fifth of the total iron has crossed the marker interface, while one-twentieth of the total oxygen has crossed in the reverse direction. The simplified result favors iron transport in the ratio four to one. However wiistite is not stoichiometric FeO. At 900°C, the temperature of the measurement, the composition is about FeO When the material balance for the same experimental result is repeated, assuming the product will be 1 mol of Fe3O4, it is found that 0.6 gram atoms of iron and 0.19 gram atoms of oxygen must have passed the marker in the same direction. (This is readily apparent from the reaction to form 1 mol of Fe3O4 SFeO The total oxygen supplied from the atmosphere is 0.61 gram atoms, but the iron which passes the marker interface, i.e., 0.6 gram atoms, requires 0.8 gram atoms of oxygen to convert it to Fe,O,.) If all the transport during magnetite growth is due to iron ion diffusion, then the marker would enclose about 85 pct of the final magnetite and the original measurement is in error by about 5 pct. This error is probably less than the uncertainty in locating the markers by autoradiography. The possibility also exists that the starting wustite was not quite saturated with oxygen and underwent further enrichment with consequent envelopment of the marker before magnetite caught up with the marker interface. In any case it appears that these measurements actually favor iron ion diffusion in magnetite overwhelmingly as the factor controlling its growth, although further experimental measurements are needed to eliminate the error in material balance described. Such studies are planned.

Jan 1, 1954

By Gary J. Brown

AMAX Coal Company, the nation's third largest coal producer operating in Indiana, Illinois and Wyoming, is a division of AMAX, INC., a United States based natural resources corporation that operates world wide. The operations in Wyoming (The Western Division) include Belle Ayr and Eagle Butte Mines. Belle Ayr Mine, located 18 miles south of Gillette, Wyoming, presently employs 440 people. It was started into production in 1973 and has been the largest producing coal mine in the United States since 1977. Final figures will show that the mine was again the largest in 1980 with production levels of approximately 16.1 million tons, total production of coal in the United States being in excess of 800 million tons during this last year. As one of the first commercial producers of sub-bituminous coal in the Powder River Basin, Belle Ayr has served as an example for the many other mines which have since been constructed in that region. The four coal storage silos are the first and most dominant features of the mine to be seen for miles across the Wyoming prairie. Each silo has the capacity to load a 110-car unit train in excess of 11,000 tons. All service facilities at the mine are under one roof. Included in the service building are off ices, warehousing, seven garage bays, and washhouse facilities for all employees. Preparation of coal for shipping at Belle Ayr consists only of crushing from pit-run size to 2 x 0-in. Primary crushing is done under the truck hoppers to 6-8-in. product size. Secondary crushing is performed in the two large crusher buildings. The smallest plant can produce at the rate of 2,500 tph, while the larger can produce

Jan 1, 1983

By Nicholas J. Grant, John S. Benjamin

A series of composite alloys containing a high volume of NiAl, Ni3Ah or CoAl, bonded with 0 to 40 vol pct of a ductile metal phase, were prepared by powder blending and hot extrusion. The binder metals were of four types: pure nickel or cobalt, near saturated solid solutions of aluminum in nickel and cobalt, type 316 stainless steel, and niobium. Sound extrusions were obtained in almost all instances. Studied or measured were the following: interaction between the alunzinides and the binders, room-temperature modulus of rupture values, 1500° and 1800°F stress rupture properties, hardness, structure, and oxidation resistance. Stable structures can be produced for 1800°F exposure, with interesting high-temperature strength and good high-temperature ductility. Oxidation resistance was excellent. A large number of experimental investigations have been made of the role of structure on the properties of cermets and composite materials. Gurland,1 Kreimer et al.,2 and Gurland and Bardzil3 have indicated the preferred particle size in carbide base cermets to be about 1 µ, with a hard phase content of 60 to 80 vol pct. The optimum ductile binder thickness was noted to be 0.3 to 0.6 µ.1 Complete separation of the hard phase particles by the binder is important in reducing the severity of brittle fracture.' The purpose of the present study was to produce structures comparable to the conventional cermets, using a series of relatively close-packed intermetal-lic compounds rather than carbides as the refractory hard phase, and to study the effects of binder content and composition on both high- and low-temperature properties. The selected intermetallic compounds were particularly of interest because of the potential they offered in yielding room-temperature ductility. The highly symmetrical structures are known to possess high-temperature ductility and room-temperature toughness. Based on a ductile binder, the alloys were prepared by the powder-metallurgy route to avoid melting and subsequent alloying of the matrix, and were extruded at relatively low temperatures. It was expected that the composite alloy would retain useful ductility. In contrast, infiltration and high-temperature sintering led to alloying of the matrix and to decreased ductility. The systems Ni-A1 and Co-A1 were selected for this study. In the Ni-A1 system the compounds NiA1, having an ordered bcc B2 structure, and Ni3Al(?1), having an ordered fcc L12 structure, were chosen. In the system Co-A1 the intermetallic compound CoAl with an ordered bcc B2 structure was used. ALLOY PREPARATION The intermetallic compounds, see Table I, were prepared by using master alloys of Ni-A1 and CO-A1, with additions of either cobalt or nickel to achieve the desired compositions. The master alloy in crushed, homogenized form, was melted with pure nickel or cobalt in an inert atmosphere, cold copper crucible, nonconsumable tungsten arc furnace. The resultant intermetallic compounds were homogenized at 2192°C in argon, crushed, and dry ball-milled in a stainless mill to -100 and -325 mesh for the Ni-A1 compounds and to -325 mesh for the CoAl compound. Finer fractions were separated for some of the composite alloys. Several ductile binders were utilized. These included Inco B nickel, 5µ ; pure cobalt, 5 µ, from Sher-ritt Gordon Mines, Ltd.; fine (-325 mesh) niobium hydride powder; fine (15 µ) type 316 stainless-steel powder; and near-saturated Ni-A1 and Co-A1 solid-solution alloys, also in fine powder form. The niobium hydride was decomposed above about 700°C in processing of the compacts in vacuum to produce niobium powder. The Ni-7.1 pct A1 and the Co-5.3 pct A1 solid-solution alloys were prepared from pure nickel or cobalt and pure aluminum by nonconsumable tungsten arc melting under an inert atmosphere. The ingots were homogenized, lathe-turned to fine chips, and dry ball-milled in air to -325 mesh powder. These solid-solution alloys are designated NiSS and CoSS; see Table I. Subsequently the hard and ductile phases were dry ball-milled as a blend. Experiments clearly established the need to coat the hard particles with the ductile binder to optimize subsequent hot compaction by extrusion. Ordinary dry mixing usually resulted in nonhomogeneous alloys which were quite brittle. Conventional cermets are consolidated by liquid phase sinteiing or infiltration, which resulis in undesirable and uncontrolled alloying of the binder phase. For this study, a loose (unsintered) powder-extrusion process was emploved, minimizing reactions between binder and hard particle, thereby permitting much greater control of composition and structure. The constituent powders were first mixed in the desired

Jan 1, 1967

E. O?C. Acker Jinzoc Adachi Truman H. Aldrich Walter H. Aldridge Anson W. Allen John H. Allen William R. Appleby W. Lawrence Austin W. S. Ayres David Baker John Henry Banks Henry C. Banon Alonzo F. Bardwell Wm de L. Benedict Robert Bentley Andrew A Blair Walter M. Brodie Elwin F. Brown Fredrick Burbidge H.H. Burden Charles Butters

Jan 1, 1941

By Frederic E. Carter

THERE have been many attempts to prove that platinum was known to the ancients, but since no traces of the metal have been found in the relics of early times, it must be concluded that it was not known to them. As far as records go, it was actually first discovered in the 16th century in a Spanish mine on the Pinto River in South America; from which source it received its name of Platina del Pinto (little silver from the Pinto). It was more or less of a rarity and was a subject of interest to a few chemists only, until the year 1822 when the metal was first discovered in Russia. In 1819 there were noticed in the washings of the gold sands of the southern part of the Ural Mountains, grains of a heavy white substance, but it was not until three years later that this substance was found to contain platinum. While at first the amounts of platinum brought from the Urals were meager, prospecting soon disclosed rich deposits extending over a considerable area, and nuggets from 10 to 20 lb. were by no means rare. This discovery assured to chemists an ample supply of platinum for their crucibles, etc. The ore is now found in various parts of the world but the richest deposits are still found in the Ural Mountains. The platinum of commerce is obtained entirely from alluvial deposits at depths varying from 6 to 40 ft. The sand and gravel of former river beds are subjected to a series of screenings and washings to effect the separation of the ore. Actually, probably all gold-bearing gravel beds of the world contain platinum, and it is more than likely that large quantities of platinum ore have been thrown away with the black sand washings from gold placer deposits. This is especially true of the alluvial deposits of the Pacific Coast in California and Oregon. Platinum ore is usually found in the form of rounded or flattened grains of "sand," and occasionally in irregular lumps of the size of peas. Large nuggets are very rare. The ore has a metallic luster and is distinguished by its steel gray color, but shows light gray streak when rubbed on a hard white surface; it has a high specific gravity, 16 to 19; is infusible in the hottest blast furnaces, and insoluble in any single acid. Platinum ore is a complex body consisting of the metal in combination with varying proportions of the other members of the platinum group; iridium,

Jan 1, 1928