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By G. Ansel, J. P. Doan

THE important literature concerning zirconium in magnesium-base alloys is predominantly contained in patent references. Sauerwald, Eisenreich, and Holub1-4 discovered the profound grain-refining influence of small amounts of zirconium on cast magnesium and the attendant increases in strength, and ductility. They extended their work to reveal that limited amounts of certain other elements, including zinc, could be added for further improvement in strength and hardness. British. Patent 5111376 relates to the parent discoveries of Sauerwald, Eisen¬reich, and Holub. All of these references deal primarily with casting characteristics and properties in the cast state. Minor mention is made of desirable tensile strength, ductility, and toughness of wrought Mg-Zr alloys* modified by one or more additional elements. No extensive reference in the literature" has been found to the particular characteristics of wrought Mg-Zn-Zr alloys, with which the present paper is concerned. - The work to be discussed represents essentially an extrusion study of the Mg-Zn-Zr alloys and indicates that this system is highly interesting in the wrought state both academically and commercially. Accordingly, an important aim of this paper is to describe the hot-workability, tension and compression properties, metal¬lography, and toughness of these alloys. Compositional variations are limited to the ranges o to 7 per cent Zn and o to I per cent Zr. EXPERIMENTAL PROCEDURE Alloying and Casting Alloying ingredients were cell mag¬nesium, commercial zinc (intermediate grade), and a chloride salt containing approximately 50 per cent ZrCl2 and 50 per cent alkali chlorides. This salt is produced by Titanium Alloy Manu¬facturing Company. Melting, alloying, and pouring procedure essentially followed the crucible process as described by Nelson.6 The magnesium was melted using Dow No. 310 flux, and the temperature raised to 1350° to 1400°F for the alloying operations. After alloying of the zinc, the zirconium containing salt was added in small portions with vigorous stirring. This is an adaptation of the method described in British Patent 533264.7 The alloying efficiency of zir¬conium was approximately 30 per cent. During the alloying of zirconium, fluorspar was added in amount required as a flux¬inspissating agent. Next the melt was refined with Dow No. 310 flux and held quietly for 15 min. Finally billets were cast in a book-type permanent mold

Jan 1, 1946

By Robert D. Gunn, John E. Boysen, Dennis D. Fischer

The second underground coal gasification experiment conducted by ERDA's Laramie Energy Research Center at a site near Hanna, Wyo., was completed on Jul. 30, 1976. During the experiment production reached 0.32 blm3/d (12 M cu ft/d) of 6.9 w/m3 gas (175 Btu per cu ft). Approximately 6100 tonnes (6700 tons) of coal were gasified during the experiment. Energy return ratios of 4.5 to 5.3, coal gas thermal efficiencies of 76 to 89%, and overall process efficiencies of 65 to 74% were achieved during the second Hanna experiment. This paper describes the experiment and the results obtained with emphasis given to the determination of the energy recovered relative to energy consumed in conducting the test. Data from this determination are compared with previously published data from the first test conducted at Hanna during 1973-74.

Jan 1, 1978

By W. H. Bassett

IN the commercial annealing of cartridge brass there are four points regarding which definite data are essential. They have to do with the correct interpretation of grain count in its relation to annealing temperature and, incidentally, to Brinell hardness. These points are: 1. The comparison of the grain sizes of two cartridge-brass mixtures: 69 copper, 31 zinc, 0.376-in. (9.5-min.) gage; and 68 copper, 32 zinc, 0.130-in. (3.3-mm.) gage. 2. The comparison of the grain sizes of annealed metal that had previously been reduced by rolling varying amounts; for instance, 20.0, 36.6, 50.9, and 59.1 per cent. 3. The determination of standards for grain sizes on annealed brass of the composition 68 per cent. copper, 32 per cent. zinc and 69 copper, 31 zinc. 4. The comparison of grain size with Brinell hardness on identical samples of annealed metal. In their comprehensive and thorough investigation of the recrystallization of cold-worked alpha brass on annealing,1 Mathewson and Phillips have discussed the relations between temperature of anneal, degree of deformation, and structural alteration in alpha brass. They have also shown certain comparisons between the ordinary physical properties and the grain size of annealed brass. The purpose of the present investigation is mainly concerned with the grain size of cartridge brass, its relation to Brinell hardness, and the publication of sufficient data to enable those engaged in the inspection of such material to have a correct foundation upon which to work.

Jan 1, 1919

By C. L. Shapiro, R. Schempp

DuRing the past few years, general interest in the steel-producing and steel-consuming industries has been centered on the so-called "inherent characteristics" of steels. While often vaguely described, these characteristics are known to influence the response to heat-treatment and the hardening characteristics of the material. Although most of the recent papers and discussions have associated the "inherent characteristics" with the austenitic grain size and emphasized the importance of it, comparatively little is known of the variables that may affect the size of the austenite grain. The work to be described in this paper was carried out during the course of a study on the inherent characteristics of tool steel containing one per cent carbon. The discrepancies encountered in the determination and classification of the austenitic grain size led to an investigation of some of the variants influencing the austenitic grain size as determined by standard methods. Methods of Determining Austenitic Grain Size The present methods used for the determination of the austenitic grain size may briefly be classified in two groups: 1. Etching at room temperature to reveal the austenite grain size prior to cooling. 2. Etching at elevated temperatures, cooling to room temperature, and observing the structural conditions that existed at the temperature from which cooling occurred. The outstanding methods of the first group are: (1) the McQuaid-Ehn test, (2) optimum rate of cooling, (3) quenching and etching. McQuaid-Ehn Test.—This established and accepted test does not need much elaboration. It consists of pack carburizing at a definite temperature for a standard period of time and slowly cooling in the furnace. The temperature is 1700" F. (925' C.) and the time is 8 hr. The interpretation and evaluation of this test are fairly well defined in the A.S.T.M.

Jan 1, 1937

By J. B. Newsom

IN the September 1936 issue of MINING AND METALLURGY the pioneer work of boring a 5-ft. shaft to a depth of 1125 ft. at the Idaho Maryland mine in California was described. Later, a Bureau of Mines Information Circular (No. 6923) gave additional data. In re¬cent months still further progress has been made in this technique through the sinking of a 5 1/2-ft. shaft for Pickands, Mather & Co. at their Zenith mine, Ely, Minn. The present work was done with new carefully designed equipment and several experienced men so that progress, as shown below has been much better:

Jan 1, 1938

By William E. Ford, Edward Salisbury Dana

General Principles of Optics Optical Instruments and Methods General Optical Characters of Minerals 1. Diaphaneity 2. Color 3. Luster Special Optical Characters of Minerals belonging to the different Systems A. Isometric Crystals B. Uniaxial Crystals General Optical Relations Optical Examination of Uniaxial Crystals C. Biaxial Crystals General Optical Relations Optical Examination of Biaxial Crystals 306. Before considering the optical characters of minerals in general, and more particularly those that belong to the crystals of the different systems, it is desirable to review briefly some of the more important principles of optics upon which the phenomena in question depend. For a fuller discussion of the o tics of crystals, special reference is made to the works of Groth (translation by Jackson), Liebisch, Mallard, Duparc and Pearce, Rosenbusch (translation by Iddings), Iddings, Johannsen, Winchell, mentioned on p. 3 also to the various advanced text-goks of Physics. 307. The Nature of Light. - Light is now considered to be an electro- magnetic phenomenon due to a periodic/variation in the energy given off by vibrating electrons. This energy is transmitted by a series of periodic changes that show all the characters of ordinary wave phenomena. The light waves, as they are commonly called, possess certain short wave-lengths that are of the correct magnitude to affect the optic nerves. Other similar waves with longer or shorter wave-lengths belong to the same class of phenomena. Immediately beyond the violet end of the visible spectrum come the so-called "ultra- violet" waves with still shorter wave-lengths and on beyond these we have the X-rays and the "gamma" rays produced by radium. Of the waves having greater lengths than those of light waves we have the waves that give

Jan 1, 1922

By John B. Myers

Vermiculite is the commercial name used to describe a micaceous mineral that expands appreciably when heated. This process, called exfoliation, results in a light weight material. The light weight material is also called vermiculite, or more exactly, expanded vermiculite. Practically all uses of vermiculite are for the expanded material. Composition and Properties Vermiculite, in its natural state, has the characteristic micaceous habit and a perfect basal cleavage and readily splits into thin laminae, which are soft, pliable, and inelastic. The monoclinic crystal faces are often marked by triangular lines at 60° and 120°. The hardness varies from 1.5 to 2 or more, depending on the composition. The specific gravity varies from 2.2 to 2.7; specific heat 0.2; fusion temperature 2,000° to 2,500°F; luster pearly to greasy; color amber, bronze, brown, dark green, and black. Feel is like talc and sometimes soapy when wet. When heated quickly at elevated temperatures, vermiculite exfoliates by expanding at right angles to the cleavage into long wormlike pieces (the name vermiculite is from the Latin vermiculari, to breed worms). This important characteristic of expansion is believed to be a mechanical separation of the layers when the contained water is converted to steam. The increase in bulk volume of commercially prepared material is 8 to 12 times, but individual flakes may expand as much as 30 times. There is no expansion parallel to the cleavage. Vermiculite may also be expanded by several chemical processes such as soaking in hydrogen peroxide, weak acids and other electrolytes. The color changes during expansion. Heat-treated material changes to a light golden bronze or cream color depending on composition. The conditions of heating affect color. Heating in an oxidizing atmosphere produces reddish colors and heating in a reducing atmosphere produces dull gray colors. The iron is generally not oxidized during chemical expansion. Vermiculite is hydrated magnesium-aluminum silicate. Although there has been much research on the chemical and structural composition, there is not yet complete agreement on the exact formula and composition. This is to be expected since vermiculite is not a mineral of fixed composition and different workers have examined different varieties. It has been proposed that vermiculite is not a single species but a family of related minerals. This has also resulted in many names for the particular vermiculite found in a certain deposit. All of this difficulty arises from the very nature of its crystal chemistry. Unlike most minerals, certain crystal structure properties and the chemical composition can be changed by the ordinary forces of nature or in the laboratory. This would suggest that vermiculite be thought of more as a variable mineral rather than a group of related species. It was stated on page 261 of this volume in the chapter on Clay Minerals by H. H. Murray of the Georgia Clay Co., that vermiculite is an equidimensional, expandable clay mineral. Gruner (ref. 14, Chap. 12) showed that the structure consists of a layer made up of two silica tetrahedral sheets with a central magnesium, iron octahedral sheet separated by two layers of water molecules and adsorbed magnesium and calcium ions. Mathieson and Walker,2a in a recent publication, agree that vermiculite must be regarded as a true clay mineral. The characteristic properties of the mineral, such as high cation ex-

Jan 1, 1960

By S. W. Zehr, G. S. Murty, W. A. Backofen

AN observation by Squires, Weiner, and phillipsl has stimulated interest in a mechanism of deformation at high temperature (above -0.5 of the absolute melting point) that is not usually thought to be involved in the creep of metals. They found precipitate-free or "denuded" zones along grain boundaries normal to the stress axis in tensile specimens of a hydrided Mg-1/2 wt pct Zr alloy after slow straining at 450° and 500°C. Their suggestion that the zones were a result of directional diffusion of magnesium atoms was supported with calculations from Harris and Jones2 which also tended to identify the process as Nabarro-Herring (N-H) creep3,4—a process that is characterized by Newtonian viscosity, with stress (o) directly proportional to strain rate (C), and one that proceeds by lattice diffusion. Material transport by diffusion along grain boundaries is an alternative basis for Newtonian viscosity, as demonstrated by Coble,5 and is favored over N-H creep for fine grain size and lower temperature.6 In either case, the strain rate sensitivity of flow stress, defined as m = d log o/d log E (which commonly appears in the empirical a = KEW), is unity. The experiments to be described here gave metallo-graphic indications of diffusional creep which were no less clear than those just cited, but the associated m (as measured by the method of Ref. 7) was much more like that of a Bingham material. For true Bingham behavior, (a — ao) E, where oo is an initial yield stress. Therefore, even if flow after yielding should occur by diffusional transport, m must increase from 0 as < is raised to reach unity only in the limit as One result is that the resistance to tensile necking conferred by Newtonian viscosity is lost, which would become increasingly apparent through the formation of more sharply defined necks as 6 is lowered. That trend appeared in these experiments. Most of the work was done on an extremely finegrained alloy of magnesium with -6 wt pct Zn and ½ wt pct Zr (Mg ZK60); the initial mean-intercept grain diameter, L, was 0.55 µ. Shown in Fig. l(a) is a germanium-shadowed carbon replica of the surface of a specimen that was coated with silicone oil,* heated to 270°C under a helium atmosphere, and then stretched locally -200 pct at an initial E = 3.3 x 10-5 sec-1. Under

Jan 1, 1969

By G. F. Comstock

THE subject of transverse fissures in steel rails has been discussed very thoroughly in recent years from various points of view and the final opinions expressed may be roughly classified into two groups: (1) That these fissures are the result merely of fatigue of the steel and are independent of the quality of the metal. (2) That the quality of the metal and the mill practice must have something to do with them. The first point of view was most-ably and logically presented by J. E. Howard,1 and in the discussion of this paper, as well as in several other preceding publications, Dr. P. H. Dudley, Consulting Engineer of the New York Central Lines, has strongly defended the other opinion.2 The steel makers of the country have naturally rallied under Mr. Howard&apos;s banner, hoping to place the entire blame for these. failures upon the railroads with their high wheel-loads, hard steel, heavy traffic, and sometimes inferior roach-bed; while the railroad men,, on the other hand, have been busy accumulating statistics and records in the effort to find an actual reason in the rails themselves that would account for the seemingly haphazard occurrence of transverse fissures under varying conditions and at widely separated points. The view that these fissures were due merely to normal fatigue under alternating stresses seemed most reasonable to the writer until quite recently, because from work clone in this laboratory, as well as the work of other investigators of the problem, no structural differences, in the vast majority of cases, were found between metal at the nuclei of transverse fissures and metal at similar positions in the same rails or in other rails that had not developed fissures. . Within the last year or two, however, since the method of etching polished sections for the microscope with a cupric chloride solution has been tried systematically. on lengthwise sections, passing through the nuclei of transverse fissures, evidence

Jan 11, 1918

By William L. Fink, E. H. Dix, L. A. Willey

The results of a preliminary investigation of the aluminum-iron-manganese system showed that small amounts of iron (0.10 per cent) substantially reduce the solid solubility of manganese in aluminum. This is clearly shown in the photomicrographs of three alloys, Figs. 1 to 3. Fig. 1, of an alloy containing 1.04 per cent manganese after a heat treatment at 626° C. for 45 hr., shows only solid solution. This alloy contained less than 0.008 per cent iron. Fig. 2 shows the abundance of a constituent (which undoubtedly contains aluminum, manganese and iron) in an alloy containing 1.00 per cent manganese and 0.11 percent iron after a solution heat treatment at 625" C. for 63 hr. For comparison, Fig. 3 is included to show the relatively small amount of constituent (FeA13) in a similarly heat-treated aluminum alloy containing 0.10 per cent iron but no manganese. These data necessitated a reconsideration of the binary aluminum-manganese diagram that was previously presented,&apos; inasmuch as the alloys used in that work contained from 0.02 to 0.05 per cent iron. This paper is the fourteenth of a series from the Research Laboratories of the Aluminum Company of America reporting the results of investigations of equilibrium relations in aluminum-base alloys of high purity. The purpose was to determine the phase relations in aluminum with aluminum-manganese alloys containing the smallest amount of iron that could be realized with the purest material available at the present time (less than 0.01 per cent iron). Since the previous publication from these laboratories, five investigations of the aluminum-manganese system have been reported. Krings and Ostmannz assigned the formula MnA14 to the compound at the aluminum end of the syst,em, and found a eutectic between this compound and aluminum at 649" C. and 3 per cent manganese.

Jan 1, 1933

By Ursula E. Wolff

Il.lechanica1 twins have been observed in brigsten single crystals of a variety of axial orientations defornzed at room temperature in tension or bending. The twins formed near the final fracture and were up to 3 p thick. The twinning plane was always of the type (113). Twinning at room ternperature occurred only after considerable prior slip. Twins usually preceded fracture and nucleated cracks. The crack surfaces often alternated between a (001) plane and the twin interfaces. Secondary twins could also nucleate from cracks. In the absence of twinning tensile samples failed by shear; twinned samples failed by cleavage. On the assumption that observed sudden load drops in the stress-strain curves are associated with twinning, a critical resolved stress for twinning of 60, 000 to 65, 000 psi was calculated. MeCHANICAL twinning has been observed in iron and iron alloys at low temperature by a number of investigators.&apos;-7 Similarly, for high-purity tungsten, twinning has been reported for deformation temperatures below 211°K.8-10 In W-Re and Mo-Re alloys, 20 pct Re was determined as the lower limit for twin formation at room temperature." Since the twins are generally very narrow, they are usually identified only by etching techniques. The expected (112) habit plane has always been confirmed by angular analysis of the surface traces. Recently, however, a complete identification by X-ray analysis has been performed on twins in a Mo-35 pct Re alloy.12 During an investigation of the deformation charac- teristics of tungsten single crystals, twins were revealed in tensile and bend samples deformed at room temperature. This paper deals with the conditions for such twinning and the relation of twinning to fracture. EXPERIMENTAL PROCEDURE Tungsten single crystals, 1/8 in. in diam, of a variety of axial orientations were grown from un-doped material by four-pass electron-beam zone melting. A representative analysis is given in the following table: From these crqstals, tensile samples with 1 in. gage lengths were made by surface grinding, leaving shoulders for gripping. The diameter after grinding was 0.082 in. The distorted surface layer was then removed by ele1:trolytic polishing which reduced the diameter of the gage length to 0.080 in. Tensile tests were carried out at room temperature in an Instron machine under two different sets of conditions: a) Rigid mounting; strain rate 0.02 in. per in. per min. b) Gimbal mounting; strain rate 0.002 in. per in. per min up to a total strain of approximately 0.2 pct, then 0.01 in. per in. per min to fracture. Stress axis and growth direction coincided in all samples and are subsequently called orientation.

Jan 1, 1962

By C. E. Cottrell, G. W. Preckshot, N. D. Delisle, D. L. Katz

Most crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir. mechanisms. Asphalt has been the subject of widespread investigation but, owing to the complexity of the substances being considered, progress has been slow. Investigators working primarily with the asphaltic substances have treated the subject from the colloidal standpoint and have developed theories that picture the asphaltic particles as surrounded by adsorbed materia1s.14,15,17,24 The deasphaltization of lubricating oil by the use of solvents treats the subject primarily from the standpoint of liquid-liquid equilibria.&apos;&apos; A complete understanding of asphaltic substances would make possible the following of the material from its initial state in the crude oil through precipitation processes to the final plastic stage, the most common form of which is used in asphaltic pavements. Since these asphaltic particles are very small, it appears &apos;hat the electron microscope4 might be a useful tool in studying the precipitation processes. Specimens are examined by the electron microscope in a vacuum and as very thin films, requiring special techniques in preparation of samples. A brief description of the electron microscope and its operation will bring out the difficulties and advantages of its use for this problem. The first work was done with crude oils that had been diluted with solvents for the preparation of the film to be examined. Later a technique was developed by which the undiluted oil film could be made thin enough for direct examination. These two techniques show vastly different results Asphaltic particles have been precipitated from crude oils by a variety of

Jan 1, 1943

By G. W. Preckshot, C. E. Cottrell, D. L. Katz, N. D. Delisle

Most crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir. mechanisms. Asphalt has been the subject of widespread investigation but, owing to the complexity of the substances being considered, progress has been slow. Investigators working primarily with the asphaltic substances have treated the subject from the colloidal standpoint and have developed theories that picture the asphaltic particles as surrounded by adsorbed materia1s.14,15,17,24 The deasphaltization of lubricating oil by the use of solvents treats the subject primarily from the standpoint of liquid-liquid equilibria.&apos;&apos; A complete understanding of asphaltic substances would make possible the following of the material from its initial state in the crude oil through precipitation processes to the final plastic stage, the most common form of which is used in asphaltic pavements. Since these asphaltic particles are very small, it appears &apos;hat the electron microscope4 might be a useful tool in studying the precipitation processes. Specimens are examined by the electron microscope in a vacuum and as very thin films, requiring special techniques in preparation of samples. A brief description of the electron microscope and its operation will bring out the difficulties and advantages of its use for this problem. The first work was done with crude oils that had been diluted with solvents for the preparation of the film to be examined. Later a technique was developed by which the undiluted oil film could be made thin enough for direct examination. These two techniques show vastly different results Asphaltic particles have been precipitated from crude oils by a variety of

Jan 1, 1943

By J. L. Stokes, L. J. Demer

It has recently been shown&apos; that epitaxial films of silicon carbide deposited on silicon single crystals possess desirable properties for semiconductor applications. There is one apparent disadvantage to such a system, however; since epitaxial deposition is a high-temperature process, it can result in plastic deformation of the silicon substrate. The accompanying Berg-Barrett X-ray diffraction photographs reveal plastic deformation in two silicon semiconductor crystals which occurred when the crystals were coated with an epitaxial layer of silicon carbide at 1150°C. Due to differences in thermal expansion between the silicon substrate and the epitaxial silicon carbide, the silicon was subjected to stresses while still in the plastic temperature range. Both crystals shown were 0.7 in. in diam and 0.0055 in. thick. The crystals were sliced from a larger crystal so that their polar axes were parallel to the [ill] direction. After cutting, the crystals were polished with diamond paste, and etched in HC1 vapor to remove surface damage re- sulting from the cutting and polishing operations. This provided clean, damage-free surfaces on which to deposit the silicon carbide. Figs. l(a) and l(b) are reflection and transmission photographs, respectively, of the same crystal. A smaller portion of the crystal is shown in the transmission geometry, because a vertical slit was

Jan 1, 1965

By John Eash

DURING recent years nickel has had an increasingly important role as an alloying element in the copper-tin bronzes. Nickel additions not only produce better casting alloys but also make alloys whose properties can be varied by precipitation hardening; thus leading to increased commercial application of copper-nickel-tin alloys. Recent investigations have indicated a decrease in the solubility of tin in the alpha phase as the annealing temperature is lowered and as the nickel content is increased within certain limits. A further change caused by the nickel additions is produced in the excess phase of the copper-tin bronzes. The alpha plus delta eutectoid is replaced by a clear precipitated constituent in the alloys containing up to 15 per cent tin and not less than 1 per cent nickel. This paper has a dual purpose. The first is to present a new determination of the alpha-phase boundary in alloys containing from 0 to 20 per cent nickel, together with the liquidus and solidus temperatures above that field. The second purpose is to give the equilibrium conditions existing in alloys exceeding the alpha phase containing up to 31 per cent tin and 5 per cent nickel, so that the disappearance of the alpha plus delta eutectoid constituent may be explained. After considering the earlier investigations of the related alloy systems and the experimental procedure used in this investigation, the alloys will be discussed in groups as separate quasibinary systems containing constant amounts of nickel. The systems considered contain 0, 1, 2, 3, 5, 10 and 20 per cent nickel. The straight copper-tin system was reinvestigated in order to establish a foundation on which to build the remaining material. The 1 per cent nickel alloys studied give the relations existing in the region of the eutectoid transformation between the copper-tin system and the 2 per cent nickel copper-tin system which has been investigated in detail. The thorough examination of the latter system was made since 2 per cent of nickel is representative of the commercial additions to the cast bronzes and also because it is sufficient to produce

Jan 1, 1932

By Charles Jackson Abrams

MINING is one of the major industries of the Rocky Mountain region and since the United States became involved in the present World War, all mines have been called upon by the Government for the maximum production of the strategic metals necessary. Operating under the most adverse conditions, such as priority requirements, slow delivery of necessary material and equipment, labor shortages, and freezing of all wages, which still permitted some industries to pay higher rates than were allowable in the mines, thereby drawing labor from the mines; and the United States Employment Service continually giving mine labor certificates of availability; these and many other problems made mine operation particularly difficult. Yet, in spite of these obstacles, the mining industry, either through its own resources or through Government subsidies in the form of loans or premium prices for strategic metal, have and still are making an all-out effort to meet Government demands. They, without question, have played a major role in assisting the war effort.

Jan 1, 1945

By John F. Elliott, Martin Weinstein

The solubility of hydrogen in liquid Pure iron and in a number of liquid binary iron alloys has been measured in a Sieverts&apos;-type apparatus. Sieverts&apos; law is obeyed in all alloys studied UP to 1 atm Pressure H2. The alloying elements, Al, B, C, Co, Cu, Ge, P, S, and Sn, decrease the solubility while Cb, Cr, Mn, and Ni increase it. ALTHOUGH the importance of hydrogen in steel-making has long been recognized, there has been, until recently, very little information in the literature on the effect of alloying elements on the solubility of hydrogen in iron. There is also disagreement on the solubility of the gas in liquid pure iron. Because of the earlier work in this laboratory,1,2 with the Sieverts method to determine the solubility of nitrogen in liquid iron alloys, it was decided to apply the equipment and procedure to hydrogen. The literature that is pertinent to this study (Ftefs. 1 through 15) will be discussed later when the results of this investigation are considered rather than at this point to avoid repetition. The reaction under study is:

Jan 1, 1963

HUDSON MAXIM, Brooklyn, N. Y.-Immediately after the creation of the Naval Consulting Board, Admiral Strauss, Chief of the Bureau of Ordnance of the Navy, told members of the Board that the most important problem for the scientists to solve was erosion in large guns. The Navy, for years, had been working on the problem with marked suceess, but there was much yet remaining to be accomplished. As Chairman of the Committee on Ordnance and Explosives of the Naval Consulting Board, I communicated with several experts in the manufacture of steel, principal among whom was Prof. Howe. He generously agreed to help in every way possible, and the work that he has done and the time that he has spent upon it can he appreciated only by reading his paper. Prof. Howe asked for some rings. from a, certain 14-in. gun which Admiral Strauss had mentioned in particular, and in which, he had informed us, at each shot the bore of the gun, was enlarged about 0.001 in.,&apos; and that after a relatively small number of rounds it was considerably eroded. It has puzzled scientists for a long time to account for the peculiar erosive effect produced by the powder gases in a gun, arid: what Prof. Howe has done in his paper is worthy of Sherlock Holmes. He is a veritable Sherlock Holmes of science.

Jan 4, 1918

By Charles H. Jacoby, Stanley J. LeFond

Salt, or halite, has had a long and most varied history. While we know the Chinese were producing salt as early as 3000 B.C., the first written reference to salt appears in the book of Job recorded about 2250 B.C., which reads: "Can nothing which is unsavory be eaten without salt?" We do not know when man first used or realized that he needed salt. Perhaps one of our early Eolithic ancestors noted a piece of salt shining along the shore of a salt lake or a bay. He may have been attracted by its shining luster and tasted it. He found that it had a tart, zesty, distinctive flavor and perhaps chewing a large piece, became ill. However, by experimentation he soon learned that taken in the proper proportions salt was a very pleasant additive to his food. He may have noticed, too, that it increased his feeling of well-being. Thus, when the curtain of recorded history rises, we find man using salt for his health&apos;s sake, seasoning his food with it, feeding it to his animals, and using it in many superstitious and religious ceremonies. These uses, however, are a far cry from the uses for salt today. The first attempts of white man to make salt in continental United States were reported in the year 1614, while the first commercial production was in 1790. Practically all of this salt was for human consumption, preserving food, and curing hides. Prior to the coming of the "white man" Indians are known to have made salt from such salt springs as those that existed at Avery Island, La., Charleston, W.Va., Saltville, Va., and Onondaga, N.Y. In 1862 the first rock salt was mined in the U.S. from the Avery Island salt dome. Almost immediately thereafter, rock salt was mined at Saltville, Va., and then at Retsof, N.Y., in 1885. Of the more than 40 million tons produced annually in the United States, about 68% or 27 million tons are consumed by the chemical industry in the production of chlorine, caustic soda, hydrochloric acid, sodium metal, and some 30 other basic chemicals. These basic chemicals, in turn, are used in the preparation of approximately 14,000 chemicals which range from soap and detergents, to such chlorinated hydrocarbons as DDT, BHC, carbon tetrachloride, etc.

Jan 1, 1975

By A. C. Heath, E. H. Dix

The importance of aluminum-silicon alloys in thc light alloy field is now generally recognized. Where silicon was once considered detrimental to the properties of aluminum, useful alloys now contain as much as 13 per cent. Furthermore, silicon is present as an impurity in aluminum of even the purest grades. Iron is another important impurity in aluminum and likc silicon is found in small quantities in the purest aluminum available today. The manner of occurrence of iron and silicon in commercially pure aluminum and many of its alloys exerts a very pronounced influence upon their properties. The effect of large quantities of iron in aluminum-silicon alloys is so detrimental that it has been found necessary to limit the allowable maximum percentage to as low a figure as is consistent with quantity production and satisfactory physical properties. The intimate relation existing between iron and silicon in aluminurn and alurninum alloys makes necessary a more complete knowledge of this ternary system. This paper is divided into two principal parts, dealing respectively with aluminum-silicon solubility equilibria and the constitution of aluminum-iron-silicon alloys. Part I.—Aluminum-silicon Alloys The early work on this system was largely confined to determining the general form of thc diagram and in this respect the results are in good agreement. Briefly, alulninunl and silicon form a simple eutectifcrous series without compounds. Until recently the solid solubility of silicon in aluminum had not been accurately determined. Ipraenkell (1908) stated that aluminum will retain 0.5 per cent. silicon in solid solu-t&apos;ion. Rosenhain, Archbutt and Hanson2 gave the maximum solubility as about 1.50 per cent. and added that "this solubility docs not appear