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By F. W. Davis

SOME idea may be gained of the tremendous consumption of refractories by the open-hearth steel manufacturers from a statement made by A. T. Green at a meeting reported by T11.e Industrial Chemist of London, as follows: "At a very progressive steel plant in the Midlands, with a battery of five open-hearth furnaces working. twelve months and making 3000 tons of steel per week, the cost of refractories per ton of steel produced averages about $0.50 for the actual open- hearth casting and $0.12 for those operations incidental to the rolling of the metal." .These figures, when translated into the annual tonnage of steel, represent a very considerable expenditure.

Jan 1, 1930

By Jack L. Taylor

As expected from similar crystal structures and favorable atomic size factors, titanium, vanadium, and molybdenum are completely soluble in one another above the transformation temperature of titanium. The fl phase parameters of the continuous solid solution are shown graphically. Limiting compositions for retained fl phase have been determined. VANADIUM and molybdenum both have body-centered-cubic structures at all temperatures and, from the atomic diameter comparison factor, 3.9 pct, would be expected to form a complete series of solid solutions. The existence of complete solubility has been confirmed by work' at the Jet Propulsion Laboratory. Furthermore, vanadium and molybdenum have favorable atomic size factors to form complete binary solid solutions with the B phase, high temperature form of titanium, which also has body-centered-cubic structure. Pietro-kowsky and Duwez' and Hansen et al." have established the existence of the complete series of solutions in these binary systems. It would be logical, therefore, to expect that p-titanium, vanadium, and molybdenum would be completely soluble in one

Jan 1, 1957

Jan 1, 1968

By William B. Hughes

The rubber-sleeve core barrel was developed to improve core recovery from unconsolidated sands, where it is most difficult to obtain cores with conventional barrels. The use of a rubber-sleeve core retainer, together with other departures from clsual design, has required a considerable amount of testing to prove its op-erability. Tests run in shallow experimental holes and in drilling wells in the U. S. and Vemzuela have, to a large extent, proved the operation of the barrel. Internal mechanism troubles, such as sandbinding of the sleeve, have been largely overcome. Cores have been recovered from completely unconsolidated sands where conventional coring has almost been abandoned because of poor recovery. In addition to retaining the core until brought to the surface, the barrel gives a "packaged-ar-cut" core, which is coilverzient for handling and transportatiorz. In the initial work, drag blade cutters, roller cutters, and tungsten carbide insert cutters were usrd for cutting unconsolidated sands. Further bit head development is presently being conducted using diamond heads in unconsolidated sands where shaler, hard sands, and limestones are encountered in adjacent formations. Thir work should render the barrel capable of cratting and recovering most types of formations, possibly including broken and frac- tured fornlations. This development is being carried on in cooperation with a diamond bit manufacturer. INTRODUCTIO N For many years the oil industry has needed greater recovery of cores from unconsolidated formations. Conventional equipment has been used to core unconsolidated sands with little success. Specifically, a core barrel was needed which would recover unconsolidated sands in a condition that would give useful reservoir information. DEVELOPMENT OF 'THE RUBBER-SLEEVE CORE BARREL Basic Requirements of Unconsolidated Sand Corino The basic need was defined as a core barrel that would obtain a continuous unconsolidated core with sand grains in place as deposited in the formation. A preliminary survey of coring equipment and search of the literature pointed out the weaknesses of conventional core barrels. Laboratory tests using unconsolidated sand in a metal tube simulated actual sand movement into the core barrel during conventional coring. In conventional barrels the core sometimes crumbles and bridges, or fails under compressive column action, becomes oversize, and wedges against the walls of the inner barrel. The core barrel requirements established by the surveys and preliminary tests are as follows. 1. The core should be held to- gether as it is cut so it cannot crumble and bridge against the walls of the coring tool, care being taken not to permit damage from fluid circulation. 2. The core should be continuously supported as it is cut so it will not have to support itself in compression. 3. The core should be packaged in the barrel to retain an undisturbed condition during the trip out of the well. The packaging should be such that the core can be removed from the barrel and shipped to the core analysis laboratory without physical disturbance or alteration of fluid content by exposure to the atmosphere. Operation of the Rubber-Sleeve Core Barrel The rubber-sleeve core barrel (Fig. 1) meets the basic requirements for the recovery of unconsolidated sands.

By M. R. Tek, L. K. Thomas, D. L. Katz

Threshold displacement pressures are needed to determine how much overpressure can be used in storing natural gas. An experimental technique for determining threshold pressures by displacing water with gas from samples saturated with water is presented. Threshold pressures for eight low permeability samples were measured. Threshold pressure data obtained in this work, plus data on higher permeability samples reported in the literature, are correlated with porosity, permeability, surface tension and formation resistivity factor. Mercury injection pressures also were measured and correlated with air-water threshold pressures. Threshold pressures were found to be independent of time. An aerial photograph of gas emerging from the top of a core shortly alter its threshold pressure has been exceeded shows that the gas bubbles are uniformly distributed across the face of the core. Channeling will occur, however, when an increased gas phase permeability is reached, A porous medium can be re resealed alter its threshold pressure has been reached, provided it has not been desaturated below a fixed saturation. Its new threshold pressure will be lower than when the sample is 100 percent saturated with water. INTRODUCTION The degree of overpressure in excess of the discovery pressure that a gas storage reservoir can withstand is determined by the ability of its caprock to contain gas, providing the pressure does not exceed the structural limit of the reservoir. The retention of gas in a reservoir by a caprock saturated with water is a result of the capillary forces acting at the gas water interface. Without the presence of water in a caprock, gas would leak out of the reservoir at a rate determined by the permeability of the caprock to gas. The ability of a caprock to contain gas is expressed in terms of its threshold displacement pressure, which is defined as the minimum pressure needed to initiate the displacement of a wetting phase by a nonwetting phase from a porous medium 100 percent saturated with the wetting phase. The gas industry must be able to predict how much "overpressure" a gas reservoir can withstand before leakage occurs by gas displacing water from caprock overlying the reservoir. This is of economic importance since the storage capacity of a gas reservoir is proportional to its pressure. The discovery pressure for most reservoirs is found between the upper and lower limits1 shown in Fig. 1. Discovery pressures in excess of their hydraulic pressure gradient are attributed to the compaction of an isolated shale formation by the overburden.2.3 The lower limit of 0.433 psi/ft corresponds to the weight of the overburden, the gradient of the rock itself. Somewhere between

Jan 1, 1969

By W. E. Remmers

THE defect in wire known as "cuppiness" has appeared and disappeared from time to time but the exact cause of its appearance or disappearance has not heretofore been known definitely. This defect is not limited to one particular metal or alloy but seems to be found at various times in all of the materials that are drawn into wire. Fig. 1 represents cuppy wire made from an aluminum alloy and Fig. 2 illustrates copper wire that became cuppy in drawing without intermediate annealing. Differences of opinion are current among the manufacturers of wire and in the literature (see Bibliography at end of paper), some believing that the source of the trouble lies in segregation in the wire rod, oxides, sulfides, slag, etc. ; others that the trouble is created by an unevenness of stress distribution across the section of the wire, usually thought of as being a function of die shape. All of the published work is of a qualitative rather than a quantitative nature. With this in mind, it was deemed advisable to make a study of the shape of the wire-drawing dies, as well as the oxygen content of the copper to be drawn.

Jan 1, 1929

By K. J. Gill, P. Chiotti

Thermal, metallographic, and vapor pressure data were obtained to establish the phase diagram for the thorium-zinc system. Four compounds corresponding to the stoichiometric formulas Th2Zn, ThZn2, ThZn4, and Th2Zn17 were observed. The melting points of these compounds under constrained vapor conditions were found to be 1055°, 1105°, 1095°, and 1015°C respectively. Four eutectics exist in this system with the following eutectic temperatures and thorium contents in wt pct: 1040°C, 89 Th; 945°C, 79 Th; 1045°C, 55 Th; and 995°C, 35 Th. The standard free energy, enthalpy, and entropy of formation for the compounds were determined from zinc vapor pressure data. ALTHOUGH the thorium-zinc system has been of technical importance in the commercial production of thorium and more recently of interest to some proposed pyrometallurgical separations processes for reactor fuels or blanket materials no detailed investigation of this system has been made in the past. Some previous work has been reviewed by Hanssen.1 The existence of four compounds, Th2Zn17, ThZn4, ThZn2, and Th2Zn has been established and their crystal structures have been studied by X-ray diffraction techniques.2-4 Smirnov et al.,5 determined the solubility of thorium in zinc and investigated the two-phase region between Th2Zn17 and zinc. They calculated some of the thermodynamic properties for these alloys from emf measurements on the cells Th/ThCl4(fused)/Cl2, C and Th2Zn17(s)+ Zn (l)/ThCl4(fused)/Cl2, C. The possibility of reaction between the anode materials and fused thorium tetrachloride to produce a lower valent thorium salt would have to be resolved in order to evaluate the results obtained. The purpose of the present investigation is to establish the phase diagram for the thorium-zinc system and to determine the standard free energy, enthalpy, and entropy of formation for the compounds formed. MATERIALS AND EXPERIMENTAL PROCEDURES The metals employed in the preparation of alloys were Bunker Hill slab zinc, 99.99 pct pure and Ames Lalboratory thorium. The major impurities in the thorium in parts per million were oxygen—1250, carbon—350, iron—100, nitrogen-75, and silicon—70. The metals in the form of several small massive pieces, total weight about 30 g, were cleaned with acid, washed with water and acetone, and dried just prior to their use for alloy preparation. Tantalum containers were found to be suitable for all the alloys studied and were used throughout this investigation. The metals were sealed inside of small 1-in.-diam tantalum crucibles by welding on preformed tantalum covers. A small thermocouple well made from 1/8-in.-diam tantalum tubing was welded in the bottom of each crucible. These crucibles were enclosed in

Jan 1, 1962

By Harry P. Hohenadel

DURING the past few years the amazing developments of the chemical industry have inspired so much publicity that the feature writers assure us that we are entering a "Chemical Age," industrially as important as the "Steel Age" and the "Electric Age," so-called. Whether or not these assurances are overstatements, it is a fact that the expansion of the chemical industry during the past 25 years has been enormous. The Chemical Bureau of the War Production Board calculates the value of chemicals produced during 1944 at $8,300,000,000, no small sum even in inflated dollars. As concerns us of the Southwest oil and gas country, four significant trends of the chemical industry are most important. (1) Many of the recently developed chemical products are new creations, not substitutes,. as new and original as the invention of the light bulb, and with a field for exploitation almost as wide. (2) Many of these chemical products will enter the mass consuming markets, which require enormous tonnages of products, and such markets are setting up an industrial demand for chemicals on a mass volume basis, compared to the relatively high-priced low-volume basis ordinarily considered as the chemical outlet of the past. (3) Most of the processes involved in producing these chemicals are adapt. able to the use, all or in part, of natural gas, oil, or refinery gases as raw mate-

Jan 1, 1945

By L. H. Simons, H. H. Spain

I NT RODUCTION Theory indicates that linear water-floods should exhibit scaling and stabilization properties in both oil-wet and water-wet porous media'. Experimental verification of these proper-ties in oil-wet media was obtained some time ago', and more recently, Perkins', employing a high permeability unconsoli dated sand and a low oil-to-water viscosity ratio, has obtained flooding data in a water-wet medium which follow the pattern of scaling and stabilization. Also, Root and Calhoun3 have found similar trends in the displacement of gas by liquids from unconsolidated sands. In general, however, the experimen-tal evidence appears still somewhat conflicting since scaling and stabilization of water floods in water-wet media has not been observed in most of the studies to date'.".'. The purpose of this paper is to provide a more comprehensive picture of waterflood behavior in water-wet media and to corroborate the validity of the scaling and stabiliza-tion concepts. The need for differentiating between the intrinsic nature of water-oil displacements inside a porous medium and perturbating secondary end effects is discussed, pertinent experimental procedures are outlined and the results of flooding tests conducted at low and at high oil-to-water viscosity ratios on con- solidated, water-wet Alundum cores are analyzed. END EFFECTS IN WATER-WET MEDIA Outlet End Effects The peculiar feature of the outlet end effect in water-wet cores is that it not only results in an excessive wetting phase saturation at the outflow face,'.' but that it also retards the moment of water breakthrough: i.e., causes an undue delay in the appearance of water in the produced effluent. Conditions existing in a water-wet core when water first arrives at the outflow face are schematically shown in Fig. 1. At this flooding stage the saturation distribution, Fig. la, has not yet been distorted by the outlet end effect. A water-invaded pore at the outlet core face, opening into the oil-filled void space between the end of the core and the end plate of the flooding cell, is illustrated in Fig. lb. The curvature of the water-oil interface is concave toward the outlet, and the pressure on the water side of the interface is lower than on the oil side by an amount equal to a certain capillary pressure (Fig. lc). Before the water (of this particular pore) can be produced from the core, it is apparent that the pressure in the water phase must exceed that in the oil outside the core. Accordingly. when water first reaches the outlet face, it will not leave the core but will accumulate inside, and only oil will be produced. Eventually, as the water injection is continued. sufficient pressure is built up in the water to reverse the curvature of the interfaces in the outlet pores, and only then will water be produced from the core. This stage, illustrated in Fig. 2. corresponds to the conventional "water breakthrough" observed in flooding experiments. For purposes of discussion, it is convenient to distinguish between the flooding stage at which water first arrives at the outlet face of a core (Fig. 1) and the stage at which water is first produced from the core ( Fig. 2). The former will be referred to as "water arrival" and the latter water breakthrough. In oil-wet media

By A. E. Anderson, H. J. Hilll

Laboratory data for 155 field muds and 77 .shales have been used to develop correlations to estimate the net streaming potential component of the SP. Analysis of these data and comparison with field tests show that streaming potential corrections must be made to obtain an accurate estimate of the electrochemical potential for use in the determinntion of formation water resi-iiviy. The self-potential curve is related to formation water resistivity, and considerable effort within the oil industry has been directed toward clarifying this relationship. The Schlumbergers and Leonardon1,2 recognized that two types of potentials, electrochemical and electro-kinetic, resulted in the net potential variation in the borehole. Most of the later papers have dealt with the electrochemical component and its controlling parameters. The investigations of Wyllie,2" Salisch' and Moore5 provide the most extensive sources of data on streaming potentials across mud cakes. These authors observed streaming potentials of sufficient magnitude to be of critical importance in SP interpretation, if it is assumed that streaming potentials develop only opposite permeable beds. Streaming potentials across shales have been reported by Schenck and by Gondouin, et al.7 Since SP magnitude is the difference in potential opposite shale and sand beds, these authors suggested that the net streaming potential component may be negligible. The present investigation was initiated to evaluate empirically some of the parameters controlling the magnitude of the net borehole streaming potential and to determine whether useful relations between mud properties and net streaming potential could be established. Field muds were used in this investigation. These muds were characterized by the amount and type of chemical treatment utilized for five days before Sampling. Filter loss, mud resistivity, mud density and filtrate resistivity were determined for each mud with conventional methods and apparatus. Mud filtrate pH was estimated with Hydrion pH paper for the appropriate range. Streaming PotentIals Across MuD Cakes Commercial calomel-saturated KC1 electrodes are subject to potential changes attributed to contamination of the very small fiber-tip bridge by particles of clay from the drilling mud.3 To minimize this difficulty, a large diameter bridge (Fig. 1) was constructed with saturated KC1-agar gel and a filter disc of microporous porcelain. Experiments showed that streaming potentials across this bridge are less than 0.2 mv at pressure dif-

By R. T. Southin

Cast ingots of 99.99 pct purity A1 and aluminum/copper alloys containing up to 2 pct Cu have been found to contain four zones rather than the three previously accepted, i.e., chill, colummar, and equiaxed zones. The fourth zone consists of a coarse dendritic layer across the top surface of the ingot which is open to the atmosphere. It is also found that the grains in the equiaxed region have a "cornet" shape, with a head which is coarsely dendritic and a tail which grew with the same structure as the columnar grains. Experiments using mechanical barriers, and others involving the elimination of the surface dendrile layer, have indicated that nucleation of the equiaxed zone is caused by the showering of dendritic particles from this surface dendrite layer. These particles are the dendritic heads found in the comet grains. A mechanism of nucleation and growth of these comet grains is put forward. Experiments with a number of other metals and alloys suggests that these conclusions may apply generally to ingots cast without the addition of nucleating agents, and solidified under normal conditions. THE macrostructure of cast ingots may contain the following three zones: i) a peripheral zone of fine equiaxed grains, commonly called the chill zone; ii) a zone of columnar grains extending inwards from the chill zone; iii) a central zone of equiaxed grains; these are normally larger than the chill grains. All three zones are not necessarily present in any particular ingot since their existence and magnitude depend upon the casting conditions and composition of the cast material. The mode of formation of zones i and ii is fairly well understood. However, the cause of the central equiaxed zone remains a matter of conjecture. Previous theories put forward to explain the mechanism of nucleation in the equiaxed zone have been examined by Chalmers1 and Winegard.2 At the time when the present work was carried out the most re -cent hypothesis was that due to Chalmers,1 who recognized more fully than previous workers that conditions in this zone during solidification were not conducive to nucleation. In his hypothesis, he suggested that nuclei were formed near the mould wall during the very early stages of solidification, and that they can drift into the central zone by convective motion. This was supported by evidence from experiments using mechanical barriers to stop the drift of nuclei. A similar hypothesis had previously been put forward by Genders.3 More recently, Jackson et al. 4 have observed that dendrite arms in organic compounds can melt off during solidification. They have postulated that this occurs in metals and alloys, and that the dendrite arms which have been freed from the main dendrite act as nuclei for the equiaxed zone. In the present work, critical metallographic examination has shown that there is a fourth zone in the macrostructure of cast ingots which is a dendritic layer over the top surface of the ingot. It is also shown that there is a relationship between this zone and nucleation of the equiaxed zone. EXPERIMENTAL DETAILS The alloys examined were prepared from super -purity aluminum of 99.99 pct min purity (spectro-graphically detected impurities of Cu, Fe, Si, and Mg) and copper of 99.98 pct min purity (spectrographically detected impurities of Si, Zn, As, Fe, Pb, Bi, Ni, Sn, Mn, Ag, Cr, and Al). Three compositions of ingots were examined, containing 0.0, 0.1, and 2 pct Cu, respectively. The alloys were melted in an alumina-lined salamander crucible using a medium-frequency electric induction furnace; when the appropriate casting temperature was reached, the alloys were cast without degassing or fluxing treatment. The mould used was made of electrode graphite and had the following dimensions: external diameter 6 in., height 9 in., with a mould cavity 8 in. deep and a diameter tapering from 5 in. at the top to 4 in. at the bottom. Casting temperatures used were generally in the order of 70" to 90°C above the liquidus and the mould was at room temperature before casting. Inserts kere placed in the mould cavity in some experiments. These consisted of either an 18-g stainless-steel tube of 2 in. diam held axially in the mould i in. off the bottom and extending 1 in. out of the top of the mould or a "trap-door" barrier of stainless-steel gauze of 24-mesh held horizontally in the mould 31/2 in. down from the top. The construction of this insert is shown in Fig. 1. All inserts were preheated prior to casting to prevent chilling. RESULTS The macrostructures of ingots of the three compositions are described, in terms of the three generally recognized zones, in Table I, and illustrated in Figs. 2(a) to (c). The most interesting observation in this table is that relating to the shape of the equiaxed grains, which were not in fact equiaxed but of almost tear-drop shape. Closer examination of these grains showed that each consisted of a head which had a coarse dendritic structure and a tail which always grew in the opposite direction to heat flow, and which had the same structure as that of the columnar material of the ingot concerned; i.e., in the pure aluminum and 0.1 pct Cu alloy it was cellular and in the 2 pct Cu alloy it was cellular-dendritic. Identification of original cast grains was greatly hampered in the super-purity aluminum ingots, and to a lesser degree in the 0.1 pct Cu alloy,

Jan 1, 1968

Jan 1, 1967

By James P. Kimball

AMONG the curious results of the recent advance of prices in the iron trade of the United States, one of them at least is to be regarded as of great importance. I allude to the utilization of mill cinder as a cheap and almost costless substitute for high-priced iron ores in many blast furnaces, situated within easy reach of such raw material. It has been, with but few exceptions, the practice in this country, based upon tradition rather than upon authority or European precedents, to waste this material on 'account of its high proportion of silicic and phosphoric acids, although known to contain more iron than most ores, and although also known to be sometimes applied to the blast furnace in greater or less quantities without serious detriment to the iron for specific purposes. While in use to a limited extent in the Hocking Valley and Hanging Rock iron regions of Ohio for several years, its use in Western Pennsylvania has only become general of late, under the exigencies of high prices and a short supply of ore. Especially has mill cinder largely entered into the stock of furnaces attached to rolling mills in and about Pittsburgh. Under such circumstances the cinder pig has been paddled on the premises, and the malleable iron produced has been unexpectedly good. Cautiously as at first mill cinder has been applied, it is evident that the temptation to use it freely is a strong one whenever the commercial rates for high-class ores are out of proportion to the general conditions of the iron trade, as sometimes happens in this country, especially as the free use of it is apparently justified by the quality of the iron produced from this cheap and abundant material. Indeed the consumption of cinder pig has., not been wholly confined to mills using up the production of furnaces belonging to the same plant. One furnace at least on the Ohio, at Covington, for several' months has been making foundry pig from "all cinder." The iron has gone into the general trade. It is probable that malleable iron of good quality can he made from the poorest cinder pig, but with what degree of economy will

Jan 1, 1881

By N. A. D. Parlee, I. D. Shah, W. C. Phelps

THIS note reports on a continuation of a program on the thermodynamics of Fe-S-X systems in the "steel-burning" temperature range begun by Bock, Barloga, and parlee.' Small coils of 0.039-in.-diameter pure iron (Ferrovac-E) wire were equilibrated with Fe-S-0 melts in ingot iron crucibles under argon at 1324°C in the assembly shown in Fig. 1, the lower part of which was heated in a large Globar furnace. Fig. 1 shows (R) the coiled iron wire sample, (M) the Fe-S-0 melt prepared from desired proportions of ferrous sulfide and ferric oxide, (K) the iron crucible, (I) a mullite guide tube, (J) an alumina crucible, (L) alundum sand, (N) crushed mullite, (Q) hollow cylinders of K30 brick, (C) a steel rod, (B), (El, (F), (G), (P), and (O), details of brass water-cooled head, and (H) a mullite tube 2-3/4 in. ID and 26 in. long. The rod (C) bearing the sample could be removed at will and be replaced by a tube for sampling the melt, or by a thermocouple for comparing the melt temperature with a control thermocouple not far from the 2-3/4-in. mullite tube. After equilibration the iron coils were treated with acid to remove the outer layer of metal and then they were analyzed for sulfur by a standard combustion method. The melt samples were analyzed for oxygen by a variation of Lander's2 hydrogen-reduction method for mattes, and for sulfur by the ASTM combustion-iodometric method NO. E 30-47. When the results of some forty-two runs were examined it was found that the sulfur and oxygen contents of the equilibrated melts showed good consistency, in that the plotted compositions fell along the smooth curve shown in Fig. 2. The points on this curve represent the experimental compositions of melts in equilibrium with ?-iron (Fe-S-0) solid solutions. These solid solutions are saturated with sulfur and oxygen with respect to the melt and therefore have the same sulfur and oxygen activities as the melt. The curve drawn through the points therefore delineates the ? liquidus. It falls in such a position as to roughly confirm the liquidus curves of Hilty and crafts3 at 1200" and 1300°C which are

Jan 1, 1965

By W. W. Beddow

TWENTY years or so ago I wrote an article on management which consisted mostly of a chart similar to thousands of others of that day showing line functions, staff functions, and the chain of command in a typical mining organization. Since hen we have been "bossing" from the faces to the swivel chair and we have made many errors of no little expense to our companies. We have kept the chart in mind but many times we have changed the functions to fit the people we have had to work with. Good management after all is getting results with the people, the equipment, the supplies, and the natural conditions of the coal seam or seams and adjacent strata present. We have made, with little effort, a good showing with average people and equipment in good natural conditions. We have made a miserable showing (although expending every personal effort) with better than aver- age people and equipment in bad natural conditions. In the latter case many of our stockholders felt that better management would have found some way to save their investment. Perhaps they were right.

Jan 1, 1944

Jan 1, 1962

By A. W. Schlechten, R. P. Abendroth

Jan 1, 1960

By R. N. Zitter

PRESENT work was done in connection with a program for obtaining a low energy gap semiconductor suitable for photodetection. The inter-metallic compound InSb, which is now being in-

Jan 1, 1959

By C. Land, R. Hultgren

Heat contents of four Cr-Ni alloys were determined in a diphenyl ethev calorimeter. Aside from ferromagnetic effects, Kopp's law of additivity of heat capacities is approximately fol-lowed, in disagreement with earlier results of A. W. Foster. In 1934 Foster1 reported heat-capacity measurements of dilute solutions of chromium in nickel, primarily as a study of the effect of alloying on the ferromagnetic Curie temperature. He found that, apart from the Curie temperature effect, the general level of heat capacities was reduced 10 pct by the addition of 1 pct Cr; 20 pct by the addition of 2 pct Cr. His measurements of pure nickel essentially agreed with accepted values. These results indicate that small amounts of dissolved chromium cause an increase in the Debye temperature of nickel, presupposing a change of frequency of interatomic bonding vibrations which is much larger than should be expected. If Foster's results were verified, therefore, they would have important implications for bonding theory. The only other heat-capacity measurements in this system seem to be those of Taylor and Hinton,' who studied anomalies which they attributed to super-lattice formation at 25 at. pct Cr. At temperatures above the anomaly, Taylor and Hinton found heat capacities at this composition were quite normal, approximately obeying Kopp's law of additivity. EXPERIMENTAL WORK In order to verify or disprove the remarkable results of Foster, the heat contents of four dilute solid solutions of chromiunn in nickel were measured in a diphenyl ether calorimeter. This instrument, described elsewhere,, operates on the principle of the Bunsen ice calorimeter, but uses diphenyl ether as the working substance. Diphenyl ether melts at the convenient temperature of 26.S°C and supplies a more sensitive measure of heat than ice. The hot sample, in an atmosphere of argon, is dropped from a furnace at a measured temperature into a chamber which is surrounded by a mixture of solid and liquid diphenyl ether. The heat from the hot specimen melts some of the solid without chang- ing the temperature of the calorimeter. The amount of solid melted, and therefore the number of calories released by the specimen, is measured from the increase of volume of the mixture, which pushes mercury down a graduated capillary tube. The apparatus has been standardized against the known heat content of pure platinum. Heat loss during the dropping of the specimen was estimated by comparing the heat content of an empty platinum capsule with a solid platinum ball of the same radius and degree of polish of the surface. Repeated tests demonstrate the precision of measurement to be closer than *0.3 pct. Smoothed experimental results are listed in Table I. The tabulated values for pure nickel are taken from kelley, several measurements were made which agreed closely with this tabulation. For chromium, however, no similar agreement was found. The values tabulated were taken from a thorough study of chromium with the diphenyl ether calorimeter which will be published elsewhere.= Suitable plots of the data showed the expected ferromagnetic anomalies in the low-chromium alloys, while the 11 pct alloy shows no ferromagnetic anomaly, but a different, small anomaly below 900°K. This is perhaps the same anomaly found in CrNi, which was once attributed to superlattice formation,' but is probably due to some other cause, such as antifer-

Jan 1, 1960

By NONE N

Jan 1, 1963