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By Bauer. Larry G.

The vast coal reserves in the Wyoming, Montana, North and South Dakota region are sufficient to supply the total energy needs of the United States for several hundred years. Not only is there an abundance of this sub-bituminous and lignite coal available, but it is easily obtainable by strip-mining . The overburden varies from several feet to several hundred feet. This western coal has yet another asset, namely, a low sulfur content. Whereas eastern and midwestern coal has a sulfur content of 2.5%, the upper Great Plains coal contains sulfur in the 0.5% range. The importance of the sulfur content of the coal is a direct result of federal government emission standards for sulfur dioxide (SO2). Hand (1) points out that "sub-bituminous coals and lignites have a propensity for retaining this sulfur in the ash under certain conditions which is not evident in higher rank coals." This would tend to reduce further the SO2 concentration in the combustion gases of boilers. Western coal is no panacea, however, in that it is far removed from most population and industrial centers. Furthermore, the moisture content of the coal varies from 20 to 40%. This moisture is almost exclusively inherent, that is, it is chemically and physically bound to the organic matter of the coal. It is believed that the water forms a part of the coal structure perhaps as water of hydration of organic salts or organic acids, perhaps by hydrogen bonding, or perhaps by simple adsorption (2). The primary market for this coal is the electric power industry. Lesser markets will be as coke for the steel industry and possible as a raw material for coal gasification and coal liquefaction plants.

Jan 1, 1983

By R. D. Nelson, J. C. Shyne

The ß and a ß transformations in plutonium were studied with particular emphasis on the transformation kinetics and microstructure. Significant observations are: 1) The kinetic data show conclusively that the ß — a transformation in high-purity plutonium can proceed isothermally with no athermal component. 2) Plastic deformation of the stable (3 phase retards the subsequent (3 — a transformation. 3) Plastic deformation of the stable a phase accelerates the a — ß transformation; the acceleration is attributed only to residual stresses. 4) The a and a?a volume changes occur anisotroPically in textured plutonium. 5) An apparent crystallogvaphic relationship exists between the parent and the product phases of the and (3 — a transformations. 6) Both applied uniaxial compressive stresses and uniaxial tensile stresses raise the starting temperature for the ß — a transformation. 7) A given uniaxial tensile stress favors the a — ß transformation more than an equivalent applied uniaxial compressive stress opposes the transformation. These observations of the (ß —a and a — ß phase changes in plutonium are consistent with known mar-tensitic transformations. ThIS paper elucidates some of the characteristics of the a— ß and ß —a transformations in plutonium. Because considerable conjecture exists about the mechanisms by which the phase transformations occur in plutonium, experiments have been performed to provide indirect information concerning the mechanisms responsible for the a —ß and ß -a transformations. Indirect information is of particular value in the study of plutonium because of the experimental difficulties presented by the metal. Single crystals have not been produced in any of the allotropes. The large density results in high X-ray and electron-absorption factors and consequently complicating X-ray and electron diffraction. The kinetics of ß — a and a — ß transformations of plutonium and the behavior of the transformations under a variety of conditions have been investigated in detail. Information about the mechanisms of the allo-tropic transformations of plutonium was obtained indirectly from three sources: 1) the effect of plastic deformation of the stable parent phase upon the transformation kinetics; 2) the behavior of the metal transforming under applied stresses; and 3) the microstruc-tural and crystallographic features between parent and product phases. PHASE-TRANSFORMATION CHARACTERISTICS In characterizing solid-state phase transformations in metals and alloys, it is useful to define several types of transformations. An aim of the present work was to identify the low-temperature transformations in plutonium by type, i.e., as martensitic or nonmar-tensitic. Practical definitions for these terms follow. The terms commonly used to categorize phase transformations lack universally accepted definitions. This confusion arises doubtlessly because some terms specify crystallographic or morphological character while other words have a kinetic or a thermodynamic connotation. For example, martensitic specifies certain definite crystallographic restrictions. Unfortunately, martensitic is sometimes used in an ill-defined way to imply kinetic characteristics. Further confusion attends the use of such expressions as nucleation and growth, diffusional, and massive. From time to time new systems of phase-transformation nomenclature are suggested; unfortunately none of these has gained general acceptance.1,2 The authors of the present paper have no intention of entering the controversy. We recognize that some readers may object to the nomencliture used here. For exampie, the terms military and civilian have recently been used in much the same way as martensitic and non-martensitic are used in this paper. This paper is intended to describe several specific details of the low-temperature phase transformations in plutonium. The authors have found it useful to identify these transformations as martensitic; the term was chosen as the best available to describe the experimentally observed features of the transformations studied. A martensitic transformation is one that occurs by the cooperative movement of many atoms; the rearrangement of atoms from parent to product crystal structure occurs by the passage of a mobile semico-herent growth interface. The geometric features characteristic of a martensitic transformation are a specific orientation relationship between the product and parent phase lattices, a specific habit-plane orientation for the growth interface, and a shape change with a specifically oriented shear component. There is no alloy partition between the parent and product phases in a martensitic transformation. Martensitic transformations may display either athermal kinetic behavior or thermally activated isothermal kinetic behavior. Some martensitic transformations occur isothermally, although more commonly martensitic transformations are athermal. Isothermal martensitic transformations are suppressible by rapid cooling. In athermal martensitic transformations, nucleation and growth are not thermally activated and the transformations are essentially time-independent. Nucleation, growth, or both can be thermally activated in isothermal martensitic reactions. Transformation of the parent phase into a marten-

Jan 1, 1967

By D. G. Westlake

The electrical resistance of a series of V-H alloys (0 to 3.5 at. pct H) has been measured over the temperature range G° to 360°. Interstitial impurities made contributions to the residual resistivity, but not the ideal resistivity. The contribution of hydrogen in solid solution is expressed by Ap = 1.12 microhm-cm per at. pct H; but the contribution of precipitated hydride was negligible. A portion of the so1vu.s for the V-H phase diagram is presented. The solubility limit is given by In N (at. pct H) = (5.828 i 0.009) - (2933 i 44)/RT. Comparison of critical temperatures joy hydride precipitation and published critical temperatures for hydrogen embrittlement suggests the two are related. ThiS study was initiated as part of an investigation of the mechanism by which small concentrations of hydrogen embrittle the hydride-forming metals at low temperatures. It has already been shown that, in the case of hcp zirconium, a reduction in ductility accompanies the strengthening resulting from precipitation of a finely dispersed hydride phase.''' Our attempts to detect a similar precipitation of a second phase at low temperatures in V-H alloys by transmission electron microscopy have been thwarted because we have been unable to prepare thin foils that are representative of the bulk material with respect to hydrogen concentrati~n.~'~ The present investigation establishes the solvus of the V-H system at subambient temperatures. Subsequently, we hope to be able to determine whether the embrittlement temperature is related to the critical temperature for precipitation of the hydride in a given V-H alloy. veleckis5 has proposed a partial phase diagram for the V-H system based on extrapolations of the pressure-composition relations he measured at higher temperatures. Kofstad and wallace' conducted a similar study of single-phase alloys but did not attempt to establish the phase diagram. Zanowick and wallace' and ~aeland' have studied a portion of the phase diagram by X-ray diffraction, but they investigated no alloys in the hydrogen concentration range 0 to 3 at. pct, the range of interest to us. EXPERIMENTAL PROCEDURE The vanadium was obtained from the Bureau of Mines, Boulder City, Nev., in the form of electrolytic crystals. The analyses supplied with them listed 230 ppm by weight metallic impurities, 20 ppm C, 100 ppm N, and 290 ppm 0. The crystals were electron-beam-melted into an ingot that was rolled to 0.64 mm. Strips, 60 mm long and 4.2 mm wide, were cut from the sheet, and both rolled surfaces were ground on wet 600-grit Sic paper to produce specimens 0.4 mm thick. They were wrapped in molybdenum foil, vacuum-encapsulated in quartz, and annealed 4 hr at 1273°K. The specimens were annealed in a dynamic vacuum of 2X lo-' Torr for 30 min at 1073°K for dehydrogenation, and charged with the desired quantity of hydrogen by allowing reaction with hydrogen gas at 1073°K for 2 hr and cooling at 100°K per hr. Purified hydrogen was obtained by thermal decomposition of UH3. Sixteen specimens were studied: two contained no hydrogen and the others had hydrogen concentrations between 0.5 and 3.5 at. pct (hydrogen analyses were done by vacuum extraction at 1073°K). Electrical resistances were measured by the four-terminal-resistor method on an apparatus similar to the one described by Horak.~ The specimen holder was designed so that both current and potential leads made spring-loaded mechanical contact with the specimen. The potential leads were 30 mm apart, and the current leads were 55 mm apart. The current was 0.10000 amp. We used the following baths for the indicated temperature ranges: liquid nitrogen, 77°K; Freon 12, 120" to 230°K; Freon 11, 230" to 290°K; and ethanol, 290" to 340°K. Temperatures lower than 77°K were achieved by allowing the specimen to warm up after removal from liquid helium. Temperatures above 77°K were measured by a calibrated copper-constantan thermocouple (soldered to the specimen holder) and below 77°K by a calibrated carbon resistor. The temperature of the bath changed less than 0.l0K between duplicate measurements of the resistance. RESULTS AND DISCUSSION Typical plots of resistivity p vs temperature T are shown in Fig. 1. In the interest of clarity, only five curves are presented and the data points have been

Jan 1, 1968

By James Douglas

IN discussing the waste upon which hinges, or is supposed to hinge, so largely the preservation of our national resources, the conclusions reached would be more reliable if actual ex¬perience were consulted, and fewer deductions were drawn from general statements, which are often the product of the imagination. It cannot be questioned that the value of by-products has not been sufficiently appreciated by us, and that our, tardiness in recovering the useful ingredients of the escaping gas of our coke-ovens is one of the most glaring instances of shortcoming in that direction. And yet even for that sin there is some palliation in the immature condition of affiliated industries. I presume that it is admitted, without argument, that, except under very exceptional conditions, all the elements cannot be recovered from most of the ores or natural products. which we treat. While it is a shame that the by-products from our coke-ovens should be dissipated, Edward W. Parker's report to the U. S. Geological Survey for 1906' supplies a fairly good excuse in justification of this appalling waste. He says (pp. 773 to 774.)

May 1, 1909

By Thomas V. Falkie

The three basic ingredients of fertilizers are nitrogen, phosphorus, and potassium. Nitrogen comes from natural gas or other sources and is usually a "manufactured" ingredient. Phosphorus and potassium come from mineral sources which are mined in open pit and underground mines all over the world. Phosphorus is one of the 15 chemical elements needed to sustain life. Along with nitrogen and potassium, it is essential to the fertility of the soil and to the growth of plant life. Plants require phosphorus for proper soil conditions, early root formation, and crop maturity. Humans and animals require phosphorus for bone and tooth development. The primary raw material for phosphorous fertilizers is phosphate rock. It is found and mined in many areas of the world. Morocco, the United States, USSR, Tunisia, and some Pacific Islands are the leading rock producers. Other sources of phosphate are guano, bone meal, and other natural organics, but these comprise a very small percentage of all phosphate used. Phosphate rock in the United States is mined in Florida, North Carolina, Tennessee, Idaho, and Montana. Florida alone produces about 70% of all the rock mined in this country, mostly from a 20 X 30 mile area in Polk and Hillsborough Counties in central Florida known as the Bone Valley district. There are phosphate reserves in many parts of Florida, and within the past three years mining has begun in north Florida in Hamilton Country (see Fig. 1). In 1967, world phosphate rock production was about 75 million short tons (st). The United States produced about 35 million st (about 47%) of which Florida produced about 25 million st (about one-third of world production). According to Phosphorus and Potassium magazine (Mar./

Jan 1, 1969

By E. Teghtsoonian, E. M. Schulson

The tensile behavior of bcc ordered P' AuZn single crystals (CsCl structure) has been investigated under varying conditions of temperature, composition, and orientation. Between -0.2 and 0.4 T, multi-stage hardening occurs fm stoichiometric and nonstoichio-metric crystals oriented near the middle of the primary stereographic triangle. At higher and lower temperatures, parabolic type hardening occurs, followed by work - softening at the higher temperatwes. Deviations from stoichiometry give rise to increased flow stresses. Multi-stage hardening was observed for most orientations, except along the [loll-[lll] boundary and near the [001] corner of the stereo -graphic triangle, where parabolic type hardening occurs. Along two slip systems, (hk0)[001] and (, operate simultaneously while in the [001] comer, slip occurs mainly on the system. Electron microscopy of deformed crystals revealed bundles of edge dislocations forming walls approximately Perpendicular to the glide plane. In general the plasticity of 4' AuZn closely resembles the plasticity of bcc crystals. In recent years, considerable interest has arisen concerning the mechanical properties of the CsCl type intermetallic compounds Ag Mg,'- Fe co,' and Ni Al.'-' The compound P'AuZn is structurally similar. It has a low and congruent melting point of 725"~,'" remains ordered up to the melting point,16 and pos-esses a range of solid solubility from 47.5 to 52.0 at. pct Au at room temperature.15 The present paper reports the results of an investigation on the general tensile behavior of material in single crystal form. Some dislocation configurations characteristic of the deformed state are also reported. The results of a detailed study of the slip geometry in AuZn are presented in a separate paper.17 PROCEDURE Alloy preparation, crystal growing techniques, and the procedure followed in selecting specimens of minimum composition variation are reported elsewhere.17 Dumb-bell shaped tensile specimens were prepared by carefully machining single crystals in a jewellers' lathe to a gage length of 0.80 in. and diam of 0.090 in. Back-reflection Laue X-ray patterns and room temperature tensile tests revealed that machining damage could be eliminated by electrochemically polishing 0.005 in. from the machined surface followed by annealing at 300°C for 1 hr. Specimens were polished in fresh 5 pct KCN solution (40°C, 12 v). Experiments were performed by gripping specimens in a self-aligning pin-chuck and threaded collet system, then straining in a floor model Instron tensile machine. All tests were performed in duplicate. Experimental variables included temperature, composition, and orientation. Unless otherwise stated the strain rate was 2.5 x 10"3 per sec. Liquid testing environments included nitrogen (WOK), nitrogen cooled petroleum ether (133" to 293"K), and silicone oil (293" to 488°K). Resolved shear stress-shear strain curves were electronically computed from autographically recorded load-elongation curves. Stress and strain were resolved on the macroscopic noncrystallographic (hkO) [001] system operative under the specific test conditions of temperature, strain rate, and orientation reported earlier.17 RESULTS The temperature dependence of the work-hardening curves is shown in Fig. 1 for gold-rich crystals of 51.0 at. pct Au oriented near the center of the stereo-graphic triangle. Over the range of intermediate temperatures from -200" to 400°K, they are very similar to those classically observed for fcc metals (reviewed by Nabarro et al.).'' The beginning of deformation is characterized by a region of decreasing hardening rate, stage 0, which is followed by a region of low linear hardening, stage I, and then a region of higher linear hardening, stage 11. At the higher temperatures, stage 111 is observed, a region of decreasing hardening rate. Over the intermediate temperature range, the extent of stage 0 and of the slow transition between stages I and I1 decreases with increasing temperature. Total ductility is large, often greater than 300 pct shear. As the temperature is either increased or decreased, the extent of stage I is decreased, giving rise to parabolic type flow and reduced ductility. Similar temperature effects have been reported for bcc ~r~stals.~~-~~ Below -14O°K, hardening is terminated in brittle fracture while above -400°K. initial hardening is followed first by work-softening and then by chisel-edge type ductile fracture. Stoichiometric (50.0 at. pct Au) and Zn-rich (51.0 at. pct Zn) crystals were also tested from 77" to -500°K. The effect of composition on the flow behavior is illus-

Jan 1, 1970

R. Schuhmann, Jr. (Purdue University)— Fulton and Chipman's results on rate of silica reduction from slags are analogous in many was to the results of Parlee, Seagle, and Schuhmann10 on rate of alumina reduction from alumina crucibles. Both investigations have given comparably low rates of reduction and slow approaches to equilibrium. Accordingly, we may hypothesize that the rate-determining step is the same in both kinds of experiments; that is, oxygen diffusion across the stagnant boundary layer on the liquid-metal side of the interface between the liquid metal and the oxide phase (slag or solid oxide). I suggest that silica reduction involves the following consecutive steps: I) At the slag-metal interface: SiO2(slag) Si+ 20 II) Transport of oxygen from slag-metal to gas-metal interface: a) diffusion across liquid-metal boundary layer at slag-metal interface. b) convection within the body of liquid metal. c) diffusion across boundary layer at metal-gas interface. 111) At the metal-gas interface: C +O- CO (gas) Iv) At the graphite-metal interface: C (graphite) -C At steelmaking temperatures it is reasonable to assume that equilibrium is attained in all three chemical reactions (I, 111, and IV) right at the respective interfaces. Convection within the stirred liquid metal (step IIb) is also rapid. Transport of Si and C should be orders of magnitude easier than transport of 0, because of the relatively high concentrations of Si and C. Accordingly, we might expect the overall reaction rate to be determined by boundary-layer diffusion of oxygen, either IIa or IIc. Fulton and Chipman's demonstration that bubbling CO through the system had no major effect on reaction rate indicates that IIc is not the slowest step. Therefore, it becomes logical to estimate the maximum rate for step IIa and to compare this theoretical estimate with Fulton and Chipman's experimental data. If oxygen diffusion across the liquid metal boundary layer at the slag metal interface (step IIa) is rate-determining, In this equation, dn sio, /dt is the rate of silica reduction in moles per sec,A is the area of slag-metal interface in sq cm, Do is the diffusivity of oxygen in sq cm per sec, 6, is the boundary layer thickness in cm, c,* is the oxygen concentration right at the slag-metal interface in moles per cubic cm, and co is the oxygen concentration in the body of the liquid metal, also in moles per cubic cm. Equilibrium data" on the silicon deoxidation reaction in liquid iron and steel at 1600°C indicate that the oxygen contents of the liquid metal in Fulton and Chipman's experiments at 1600°C probably fell in the range of 0.5 x10-3 x10-3wt pct. That is, the maximum conceivable value of co*-co for the system under consideration was on the order of 10"5 mole oxygen per cubic cm. On the basis of previously published data,1O,11 it is estimated that Do/0 will fall somewhere in the range from 10-3 to 10-1 cm per sec. The surface area A in Fulton and Chipman's experiments was approximately 20 sq cm, and the weight of metal involved was about 500 grams. Combination of all these figures with the above rate equation leads to an estimate that the rate of silica reduction should fall within the range from 0.002 to 0.2 wt pct Si per hr. This estimate is consistent with the experimental data. For example, Fulton and Chipman's Fig. 2 shows a change of about 0.3 pct Si in 10 hr, corresponding to an average rate of 0.03 pct per hr. According to the proposed hypothesis, increasing the temperature will increase the reaction rate ill two ways: 1) by increasing oxygen diffusivity and 2) by increasing the oxygen concentration (oxygen solubility) in the liquid metal. The combination of these two effects accounts for the high value of the observed activation energy. Summarizing, I propose that the rate of silica reduction, like that of the carbon-oxygen reaction, is diffusion controlled and that low oxygen concentration in the liquid metal is the major factor accounting for the very low observed rates of silica reduction. John Chipman (author's reply)—The authors thank Professor Schuhmann for his interesting contribution. His proposed explanation may well prove to be the correct one. There is clearly a need for much further experimental work on this problem, and further research is in progress.

Jan 1, 1961

By M. Amsterdam, F. Rothwarf, L. Muldawer

SILVER-cadmium near the composition AgCd shows three equilibrium phases. As with 13 brass, the high temperature phase is disordered body-centered cubic (8) and the low temperature phase has the ordered CsCl structure . However, there is an intermediate temperature phase which is hexagonal close-packed ((). In a recent paper, Speich and Mack' report on a study of the Ag-Cd eutectoid near the AgCd composition. Unfortunately, the phase diagram upon which they base some of their conclusions is incorrect. That diagram is taken from the Metals Handbook' and the error is that the 0 and ( phases have been interchanged. The Handbook gives the low temperature phase as hexagonal (designated 5) and the intermediate temperature phase as cubic ordered (designated . The error may be typographical or it may be one of confusion resulting from the use of 5, ,, and 0 for the intermediate phase in various papers. A careful search of the literature reveals that a number of authors have indicated the correct relative positions of the 13, 5, and 0 phases. The comprehensive work of Fraenkel and Wolf clearly stated that the high and the low temperature phases are either identical or are very similar. olander,' on the basis of electrochemical measurements, showed that the 13 phase is disordered and the 1 phase (designated 8" in his paper and in refs. 3 and 5) is ordered. Further work by Durrant5 using thermal and metallographic analyses provided a more precise phase diagram. A summary of these works was given by Hansen6 and shows the correct relative positions of the phases. Owen, Rogers, and Guthrie7 located correctly the upper two phases by X-ray diffraction. Their failure to find the low tem-

Jan 1, 1954

By E. W. Stewart, G. P. Conard, J. F. Libsch

The effects of several additives upon the reduction characteristics of hydrogen-reduced ferrous formate are described. The various additives inhibit sintering of the reduced iron particles by apparently different mechanisms. The magnetic properties of the low density compacts produced from the resulting ultra-fine iron powders were improved markedly. THE permanent magnetic characteristics of ultra-fine iron powder prepared by various means have been a subject of considerable interest and experimentation in the past few years. When such particles are small enough to show single domain behavior, they possess' 1—permanent saturation magnetization, and 2—high coercive force. In the absence of domain boundaries, the only magnetization changes in a particle occur through spin rotation which is opposed by relatively large anisotropy forces. With decreasing particle size, the coercive force tends to increase to a maximum and then decrease because of the instability in magnetization associated with thermal fluctuations. Kittel' has calculated the critical diameter at which a spherical particle of iron can no longer sustain domain boundaries or walls to be approximately 1.5x10-' cm. Stoner and Wohlfarthr in England and Neel4,6 in France have shown from purely theoretical calculations that the high coercive force expected from single domain particles is dependent upon crystal anisotropy, shape anisotropy, or strain anisotropy contributions. Further work by Weil, Bertaut,' and many others has contributed much to the understanding of fine particle theory. Neel and Meikeljohn" have demonstrated that a decrease in particle size below a critical value of approximately 160A leads to a quite rapid decrease in coercive force because of the prevention of stable magnetization by thermal agitation. Lih1, working with powders prepared by the reduction of formate and oxalate salts of iron, has shown the marked influence of powder purity upon magnetic properties. Maximum coercive force was obtained in powders of approximately 65 pct metallic iron content while the maximum energy product, (BxH) occurred in powders of 85 pct metallic iron content. Careful consideration of the preceding theoretical considerations and experimental results has led to the manufacture of permanent magnets from ultra-fine ferromagnetic powders by powder metallurgy techniques. Such work has been done by Dean and Davis," the Ugine Co. of France, and Kopelman." The aforementioned work of Kopelman and the Ugine Co. was concerned somewhat with the effect of various additives upon the properties of hydrogen-reduced ferrous formate. Virtually no work, however, has been published on the effects of additives on the reduction rates of metal formates, although unpublished work by Ananthanarayanan16 howed promise of improved energy product in ultra-fine iron compacts prepared by the hydrogen reduction of a coprecipitated mixture of magnesium and ferrous formate. After consideration of the preceding information, it was hoped that a better balance between the metallic iron content and particle size of the reduced iron powder could be accomplished by a prevention of the attendant sintering of the partially reduced iron powder during the reduction reaction. It appeared possible that magnesium oxide might interpose a mechanical barrier between adjacent iron particles and prevent their sintering together, while metallic cadmium and metallic tin would interpose a liquid barrier which might accomplish the same purpose. The degree to which these materials were effective in accomplishing the foregoing objective and the experimental details associated with the work are reported in the following sections of this paper. Experimental Procedure Preparation of Formate and Oxide Mixtures: To obtain ferrous formate of reproducible reduction characteristics, a slight modification' was made in the technique of Fraioli and Rhoda." A supersaturated solution of ferrous formate was mixed with an equal volume of 95 pct ethyl alcohol and the formate crystals precipitated by stirring and screened to —325 mesh. These crystals were in the shape of elongated hexagons, approximately 4x10 micron in dimension. Various preparations of such ferrous formate, designated as lot 111, were reduced for 2 hr, yielding ultra-fine iron particles of exceedingly reproducible size, metallic iron content, and magnetic properties. The magnesium and cadmium formates were prepared by the reaction of dilute formic acid with their respective carbonates, while the tin formate was prepared by the reaction of dilute formic acid with stannous hydroxide. To evaluate the effect of metallic formate additives in intimate mixture with the ferrous formate, varying amounts of magnesium, cadmium, and tin formates were coprecipitated with the latter. The designations of these materials and their chemical compositions are given in Table I. Due to the differing solubilities of the various formates in aqueous media,

Jan 1, 1956

By J. W. Downey, M. V. Nevitt

The phase boundaries for the 950" isothermal sections in the ternary systems Zr-Co-0 and `Zr-Ni-0 have been determined for the composition range from 50 to 100 at. pct Zr. The two systems show very similar phase relations, having no extensive solid solution phase fields. Each contains a ternary phase. These phases are apparently isostructural, but their structure has not been determined. Some aspects of the phase relations are discussed in terms of the alloying behavior of transition metals. THE work described in this paper is the outgrowth of a recent study of the occurrence of phases having the Ti2Ni-type structure (structure-type E9,) in certain ternary systems involving Ti, Zr, or Hf with another transition metal and O.", In the Zr-CO-0 and Zr-Ni-0 systems no Ti2Ni-type phases were found to occur. However, there are several interesting aspects of the phase relations in the two systems which have significance from the point of view of the alloying behavior of transition metals. The results of this investigation may also have some importance in studies of the oxidation of Zr-Co and Zr-Ni alloys. In both the Zr-Co-0 and Zr-Ni-0 systems only the 950" isothermal sections were investigated and, as a further restriction, the study was limited to the composition range from 50 to 100 at. pct Zr. A tentative Zr-Co binary diagram has been published by Larsen, Williams, and Pehin. In the composition range pertinent to the present work they report a eutectic at 980°C and 75.9 at. pct Zr, the products of which are the terminal solid solution based on /3 Zr and the compound Zr2Co, and a eutectic at 1080" and 64.8 at. pct Zr whose products are Zr,Co and ZrCo. The solid solution based on /3 Zr is shown to decompose eutectoidally at 826°C into a Zr and Zr2Co. The limits of solubility of Co in a and /3 Zr have not been established. The structure of Zr2Co is not identified in the publication just cited. Dwight has reported that ZrCo has the CsC1-type strcture. The Zr-rich portion of the Zr-Ni diagram has been determined by Hayes, Roberson, and Paasche." The phase relations are very similar to those of the ZrCo system. A eutectic reaction whose products are /3 Zr containing 2.9 at. pct Ni and Zr,Ni occurs at 961°c, and a eutectic between Zr,Ni and ZrNi is found at 985". The solid solution based on /3 Zr decomposes eutectoidally at 808°C. The solubility of Ni in a Zr is not known accurately but is believed to be very small. Smith, Kirkpatrick, Bailey, and Williams7 have found that Zr2Ni has a tetragonal structure of the A1,Cu-type and that ZrNi is orthorhombic. Domagala and McPherson8 have published a constitution diagram for the system Zr-ZrO,. At 950" their diagram indicates that the solid solution of 0 in 0 Zr is stable from 0 to 0.5 at. pct while the phase field of 0 in a Zr extends from 6 to 29 at. pct. These solubility limits were adopted in the present study and no binary Zr-0 alloys were made. No previous data on the phase diagrams of the ternary systems are known to exist. EXPERIMENTAL PROCEDURE The experimental details involved in the preparation of alloys in this laboratory by arc melting have been described in several previous papers"3 and they will not be repeated here. Information concerning the purity of the metals used is given in Table I. Oxygen was added in the form of reagent grade ZrO,. All of the cast specimens in both alloy systems were annealed in air-atmosphere tube furnaces at 950 3' for 72 hr and water quenched. The specimens were protected from oxidation by wrapping them in Mo foil and sealing them in quartz tubes that had been evacuated at room temperature to a pressure of 1 x 10B mm of Hg. The phase boundaries were determined by metallography, and identification of the phases was accomplished primarily by X-ray diffraction methods which employed a powder camera having a diameter of 114.6 mm. The diffraction techniques which are in use in this laboratory have been previously described.' An etchant that proved satisfactory for most of the alloys consisted of 5 pct by vol of AgNO

Jan 1, 1962

By AIME AIME

THE technical material in hand and the plans under way for the 141st meeting of the Institute clearly indicate a well-rounded program of unusual excellence. The meeting will be held in the Engineering Societies Building, Feb. 15 to 18, and while it is too early to announce definitely the time of the various sessions much of the detail has been organized up to that point. Every group in the Institute membership will find much of special interest, and several features should prove generally attractive. The various committees in charge of the lighter side of the meeting are hard at work to emulate the standard established last February In this connection and in this paragraph it will suffice to say-there will be a Smoker-dinner! The Committee on Mining Methods plans two sessions for which these papers are in prospect:

Jan 1, 1932

Jan 1, 1961

Jan 1, 1893

By John Birkinbine

A specimen of brown hematite, taken from an iron-ore mine near Anniston, Alabama, exhibits a metallic streak or thread running throngh it. This specimen having been sent to me, I have no personal knowledge of its occurrence; but Mr. Albert E. Noble

Jan 1, 1895

By M. C. Fuerstenau, D. N. Collins, R. B. Bhappu, D. N. Moir

D. N. Moir (Senior Scientific Officer, Warren Spring Laboratory, D.S.I.R. Stevenage) and D. N. Collins (Scientific Officer, Warren Spring Laboratory, D.S.I.R., Stevenage, England) — During work on the petroleum sulphonate flotation of beryl in 1959 at Harwell, and subsequently at Warren Spring Laboratory, effects similar to those mentioned by the authors were noticed. Brief details of some of this work were given to the 6th International Mineral Processing Congress at Cannes.' It is interesting to note that the authors experienced strong activation effects with Fe+++ ions on beryl when using petroleum sulphonate collectors. This phenomenon was of interest in our work when

Jan 1, 1963

By E. C. Pechin

THE Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

Jan 1, 1874

By Edmund C. Pechin

The Lucy furnace, owned by Messrs. Carnegie, Kloman & Co., and located on the Alleghany River, on the outskirts of Pittsburgh, is a splendid modern furnace, 75 feet high, and 20 feet bosh. She had been working well on low grade ores of about 50 per cent., producing daily 68 to 75 tons. There was on stock 500 tons of Republic ore, one of the purest and best of the Lake Superior ores, averaging over 68 per cent. of iron, which had been procured for the purpose of making a trial for Bessemer iron. This was charged by itself, and Mr. Skelding, the founder, reports that he did not succeed in getting a single cast when it came down, before the furnace chilled from the hearth to the top of the boshes, some 25 feet. Every effort was made to save her, without avail, and the disagree-

By S. Norton

GEORGE C. FOOTS, Port Henry, N. Y. (written discussion).-The paper by Mr. Norton and Mr. LeFevre will bear the most careful consideration by all interested in the iron business, particularly in the East. There is much information contained therein which should be emphasized. The idea of handling iron-bearing rock in quantities comparable to the porphyry coppers does seem at first blush to be beyond the pale of commercial possibility. Yet, today in the Adirondack region 25 per cent.

Jan 4, 1917

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Assayer and chemist with experience in gold and silver work and refining; used to handling a force of men. Large property in Northern Ontario. Send reference, record of practice, age, married or single, and salary expected. Apply Position 54. Metallurgical chemist wanted, competent to make the following analyses: cupola, gray iron; air:-furnace iron; pig iron of various kinds; coal; coke; sand of all descriptions; materials used in modern foundry practice; steel, and bronzes of all kinds; oils for fuel in Diesel engines and lubricating purposes; materials used in a modern machine shop, in fact, all materials likely to be used in a foundry, machine shop and forge shop. No. 55.

Jan 12, 1915