Search Documents

By Lars Thomassen, Ernest Kirkendall, Clair Upthegrove

THE amount of research done in the last few years on the subject of diffusion in solid metals is significant of the importance of this problem. To review the literature dealing with diffusion is unnecessary here. Desch1 in 1912 reviewed the work that had been done on diffusion in solids and gave a bibliography of the literature published before that time. Mehl's paper in 19362 is an excellent review of diffusion in metals and contains a large bibliography. Of importance also for its review and bibliography is an article by A. I. Krynitsky.3 While considerable material has appeared in the literature on diffusion in brass, the amount of information is not great compared to that pertaining to some of the other alloys. Most of the information published is of a qualitative nature; that which is quantitative varies considerably. Thus the quantitative determination of the rates of diffusion of copper and zinc in alpha brass by a new method appeared worth while. In the present investigation the rate of diffusion of zinc in approximately the same composition alpha brass has been determined at three temperatures. PROCEDURE The method used consisted of plating copper on a beta brass, heating it to allow diffusion to take place, and measuring the concentration of copper by determining the lattice constant of the alloy. This method is unique in that it uses a beta brass of such a composition that at the temperature at which diffusion takes place the beta brass is saturated with copper. Thus, while the beta brass supplies the zinc, no diffusion takes

Jan 1, 1938

By G. T. Murray

The aging behavior of a Cu-Ti (3.2 at. pct Ti) alloy has been followed by electrical resistivity, hardness, and metallographic changes. The resistivity data indicate two principal processes, the first causing a sharp decrease in resistivity, and the second, which occurs over a long period of time, a much smaller rate of decrease. Lamellar nodules, Widmanstätten platelets, and homogeneous continuous precipitation was observed. The Widmanstätten platelets grow at the expense of the latter. When this study was initiated, little information was available on the aging behavior of copper-base titanium alloys. Several articles'-3 that appeared in the early 1930's showed that these alloys could be strengthened by precipitation, but a detailed study was not made. Within the past year, however, two other more comprehensive studies4'5 have been reported in the literature, one consisting primarily of an investigation of mechanical properties, the other

Jan 1, 1961

By Ralph D. Parker

The Frood mine (Fig. 1) is 2½ miles north of Sudbury, at a general elevation of 1000 ft. above sea level. It includes the original Frood location, which was the No. 3 mine of the Canadian Copper Co., and the adjoining Frood Extension, which until 1929 belonged to the Mond Nickel Co. Mine Openings The mine is operated from two vertical shafts and one underground incline shaft. No. 3, for men, supplies and ore, is a vertical six-compartment shaft in the footwall of the south mining area and extends froin surface to a depth of 3045 ft. No. 4 is a vertical three-compartment shaft, 2500 ft. north of No. 3 and adjacent to the north mining area. It extends from surface to a depth of 3345 ft., and is used exclusively for hoisting ore. No. 5 shaft, inclined at 65' to the horizontal and of three compartments, is near No. 4 and extends from the 2600-ft. level to 77 ft. below the 3100 level. It is used for development below the 2800 level. The ventilation shaft, No. 1, with which this paper is directly concerned, will be described fully in the following pages. Mining Methods The orcbody is laid out in 80-ft. sections at right angles to the gcneral strike and numerically indicated from the southern extremity toward the north. Each section consists of a 45-ft. stope and a 35-ft. pillar, extending the full width of the orebody. Pillars and stopes are superimposed from level to level. The present mining territory is divided into two vertical areas, a north and a south area. Both areas have the same number of stopes on each level, the two areas being separated by 10 sections to be mined later. In a few instances, at the ends of the south area, where the orebody has narrowed, longitudinal stopes are used, of more than the usual 45-ft. width. It will thus be seen that mining operations hare been concentrated in two relatively small areas, offering

Jan 1, 1934

By Robert D. Pike

IN November 1939, on behalf of the Harbison-Walker Refractories Co., the author undertook the study of the problem of utilizing the dolomite of northwestern Ohio for the manufacture of calcined magnesia suitable for use in refractories. Grateful acknowledgment is made of the unfailing assistance and encouragement throughout this work from the executive and technical staff of Harbison-Walker Refractories Company. The dolomite of the Niagara formation that is exposed or near the surface of a wide area in northwestern Ohio1 constitutes a vast supply of almost pure dolomite. It offers a virtually unlimited supply of cheap raw material of uniform dependable analysis for the manufacture of magnesia. A typical analysis of dolomite from the vicinity of Luckey, Ohio, follows: [ ] Brines containing magnesium chloride or sea water can be reacted with calcined dolomite to produce magnesia.2,3 In such reactions the MgCl2 of the brine supplies some of the magnesia and the amount of dolomite required is thereby reduced by an equivalent amount, but brines of commercial importance containing magnesium chloride are some distance away from the purest grades of the dolomite of northwestern Ohio. It was decided therefore to concentrate upon the development of a suitable process for separating the lime and magnesia of dolomite, depend¬ing upon the dolomite itself as the sole source of magnesia. This would make it possible to place a plant at the dolomite quarry, thus eliminating the cost of transporting the stone and also rendering the calcined magnesia available at a most convenient production point, considering the cost of delivery throughout the steel industry. The selection of a process depending solely upon the dolomite as a source of magnesia also necessarily entails production of the lime content of the dolomite as a by-product. It was recognized that if such a lime by-product could be produced in a suitable form, a plant location in northwestern Ohio would also be advantageous for marketing the lime. The problem, therefore, was the discovery and development of a low-cost process for separating the magnesia and lime of the dolomite of northwestern Ohio and producing each in a form relatively free from the other, and meeting the respective requirements of established markets. A satisfactory solution of this problem has been found, and it is the

Jan 1, 1947

By Henry S. Washington

I. INTRODUCTION. DURING the last twenty years or so the chemical investigation of rocks has made great advances, and it is now generally recognized that a knowledge of the chemical composition is as essential as that of the texture or mineral composition-if not more so-for the proper classification of rocks and study of their origin and relationships. Rock-analyses have vastly increased in number and, what is of greater importance, in quality. New and improved methods permit of greater accuracy than was possible in the early days, and the list of chemical constituents frequently determined has risen from the seven or eight of the greater part of the nineteenth century, to twenty or more. Indeed, rock-analyses with determinations of so many constituents ire now commonly made by the chemists of the United States and Australia, while in Germany, Great Britain, France, and Italy the rarer constituents are determined more frequently-than formerly. As a consequence of this modern, accurate work, it has been discovered that some elements which were formerly supposed to be rare are of wide-spread occurrence and are often present in considerable amount. The fact is further being developed that the elements tend to show certain relations of occurrence or abundance in connection with each other. This is a fact which is applicable to the rarer elements, and which also finds a broad geological and petrological expression in the recognition of petrographic provinces. We are beginning to obtain some definite, though as yet rudimentary, knowledge of the distribution of the elements among igneous rocks. Some of the results along these lines obtained by study of the vast accumulation of analytical data now available are well known to petrologists, while others do not seem to be so gener-

Jan 1, 1913

By A. M. Gaudin

Of the various reagents employed in the flotation of zinc-bearing ores none have attained the wide popularity that is enjoyed at present by xanthates, copper sulfate and cyanides. This situation suggests the existence of an unusual dependence in the reactions of these chemicals and of sphalerite. A study of the flotative characteristics of sphalerite when using xanthates as collectors, as related to the chemical properties of copper salts and cyanides, has therefore been conducted at the University of Utah by the writer and his associates1 during the period of 1926 to 1929. In perusing the technical literature concerning the flotation of zinc ores and of zinc-bearing lead and copper ores, a striking and general lack of agreement as to the floatability of sphalerite was observed. The underlying cause for the erratic behavior of sphalerite has not been definitely ascertained but the presence in various proportions of iron sulfide in solid solution in the sphalerite has frequently been implicitly regarded as a major factor in this respect. Although the effect of iron sulfide in solid solution in sphalerite has not been investigated in relation to the behavior of sphalerite in flotation, it is likely that it is not as important a factor as was thought at one time. The variable float-ability of sphalerite has led to the use of fairly large amounts of cyanide to prevent its flotation in the case of certain ores, whereas mere fractions of that amount of cyanide, or even none at all, have been sufficient to achieve the same result for other ores2 Similarly, the amount of copper sulfate used to promote the flotation of sphalerite has been found to vary widely. Effect of Copper Salts in Distilled Water on Sphalerite In the work at the University of Utah, over a year was spent in futile attempts at duplicating experiments until it was discovered that the

Jan 1, 1930

By d&apos, C. Antonio, S. H. Reichman

In the course of our studies of the annealing behavior of vapor-deposited silver films we have determined the electrical resistivity as a function of annealing temperature for films in the thickness range of 630 to 3240A. Fig. 1 shows the resistivity of the silver films vs film thickness in as-deposited and annealed conditions. The films were prepared by depositing 99.999 pct pure silver from molybdenum boats onto Vycor substrates. Deposition was conducted at a residual pressure of 5 x 10"6 Torr at rates of 20 to 408, sec-'. Thicknesses were determined using a multiple-beam interferometer. During annealing, resistance was measured using the four-probe method. Measurements were made every 5°C during two consecutive anneals to 300°C under a continuous vacuum of 2 x X6 Torr. The heating and cooling rates during annealing were approximately l° and 2°C min-', respectively. Typical resistivity vs temperature curves are shown in Figs. 2 through 4. There is an inflection point evident at 120°C on Fig. 2, the first anneal of a 3240A film. This inflection point was found on all films above approximately 1!00A on both first and second anneals. Below 1400A the inflection occurred at approximately 180°C. Figs; 3 and 4 show the first and second anneals of a 1370A film. The inflection point occurs at 180°C on the first anneal and approximately 120°C on the second. Our interpretation of this phenomenon is based on oxygen liberation from the film surface. It is well-documented that the presence of oxygen on silver surfaces causes a reversible increase in resistivity.1"3 The liberation of this oxygen, for example during vacuum annealing, would therefore cause a decrease in resistivity as observed on Figs. 2, 3, and 4 as a change in slope. This is accounted for by the decomposition of Ag20 on the film surface. The free energy of AgzO becomes positive between 125" and 225°C.4 The thickness dependence of the inflection points can be explained as an orientation effect. The films used in this study were preferentially oriented with their (111) planes parallel to the Substrate.''~ In addition it has been sten that the thinner films, below approximately 1500A, possess a decided "hill and valley"

Jan 1, 1969

By Y. C. Liu, W. R. Hibbard

An analysis of the relationship between the deformation and recrystallization textures in face-centered-cubic metals is presented. The analysis assumes that orientations of the secondary as well as the primary textures are related to the deformation texture. The effect of alloying elements on the recrystallization texture of copper-base alloys is also discussed. ROTATIONAL relationships based on prior orientations have been used to derive both the primary and secondary recrystallization textures."" This similarity suggests that, if the secondary texture arises from grains formed during primary recrystallization, as proposed by Dunn: and if primary recrystallization derives its lineage from the deformation structure, then the orientations obtained in secondary recrystallization .as well as those obtained in primary recrystallization should be related to the deformation texture. The following discussions are

Jan 1, 1956

By Walter Miller

Hundred-octane aviation gasoiine, toluene for T.N.T. production, high-quality lubricating oils for the needs of aviation and the armed forces, and synthetic chemicals for rubber manufacture again commanded the top priorities of the petroleum refining industry in 1944, the third year of America's active participation in the war. The objective continued to be to produce more and more of these materials—to keep up with increasingly greater requirements. By the end of the year all of the new installations projected before 1944, with the exception of possibly two or three that will tail over into January or February of 1945, had been completed and put into operation. And with the completion and putting into operation of these various units and the consequent lessening of construction responsibilities and problems, the industry was put into position to concentrate on the new operations and devote much more of its time and effort looking toward maximum output, both as to quantity and quality from the new facilities. Aviation Gasoline Making high-octane aviation gasoline continued to be the prime requisite of refining activities during 1944 as it was in the two previous war years, with the sights at the end of the year set to still higher figures than those which had been previously projected. About July I the daily output had been raised to 400,000 bbl., with some few large plant installations still to be completed and put into operation. Indications were that by December production would be up to all requirements, with good inventories. However, although by the end of the year the industry was turning out something over 500,000 bbl. a day, the estimated requirements of the armed services had been raised by a considerable figure, owing to the greatly increased aerial activities both in the European and Far Eastern combat areas. By the end of the year, therefore, the picture had changed, with the prospect for a much longer continuation of the European war, so that even with the completion and putting into operation in the United States by January 1945 of the last two or three 100-octane units authorized prior to 1944, it was evident it would be necessary to make still greater efforts to increase output of existing facilities to keep safely ahead of the game. Efforts of the industry and the Petroleum Administration for War as well as the Technical Advisory Committee and other research and development groups are concentrated therefore on methods and means of further augmenting the produc. tion of all existing refinery facilities engaged in making 100-octane aviation gasoline and components entering into it. The goal will be reached.

Jan 1, 1945

By Edgar G. Hill

MUCH has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the [ ] united States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering view-point, pointing out the effect of the volumes transported, and the load factor at which they are operated, on the unit costs of transportation, as well as the effects on costs of the character of the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the [ ] refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. BASIC FORMULA FOR FLOW OF CRUDE OIL The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By John R. Freeman

THIS paper relates entirely to the casting of brass under fluid pressure in steel dies Die castings of metals and alloys of low melting point have been available for many years but the development of brass die castings has been relatively recent, occurring within the past five years The successful development of brass die castings has resulted from the availability of alloy steels that would give satisfactory life as dies and the development of suitable die-casting machines The melting point of copper is 1084° C (1983° F ) and of a high brass about 900° C (1652° F ), as compared to 327 5° C (6215 °F) for lead, 419 4° C (786 7° F) for zinc and 658 7° C (1217 7° F) for aluminum, temperatures that ale indicative of the casting temperatures required for the various types of alloys, of which the melting points are somewhat lower than those of the pure metals TYPE OF DIE-CASTING MACHINE In the well-known plunger and gooseneck types of die-casting machines used for casting the alloys of relatively lower melting point, much of the working mechanism is immersed in the molten alloy For alloys having the relatively high melting point of brass, this obviously is impossible Machines with a separate melting chamber are essential Two rather distinct types are in extensive use at the present time, the Pack and Polak machines, the former designed by Charles Pack and developed at the American Brass Co , the latter developed by Zoseph Polak, of Prague, Czechoslovakia The principles of operation of these machines have been described in articles by Pack1,2,3 and by Sieg 4

Jan 1, 1935

By Arthur F. Taggart

PROGRESS in a technical art is of several kinds. It springs .from many diverse sources. It comprises invention, mechanical improvement, operating advance, analytical study, education. Invention is, by definition, a relatively great, essentially individual step, taken quickly. Operating advance is the slow, cumulated march of practice; in contrast, it moves at the pace of the tortoise, but over, the years its effects rival and, in some cases, surpass those of invention. Mechanical improvement- is a usual concomitant of the reduction of invention. to operating practice; thereafter it is a primary tool of operating advance. Analytical study is the process of mental digestion of the fruits of invention and practice. Its purpose is to render these into a form assimilable by the art as a whole, and by the perennial crop of would be practitioners. Education, disseminating the results of such study, consolidates and maintains the positions gained. Thus, slowly at first, but continuously accelerating, the tide of progress grows- to flood. Such growth, in mathematical parlance, is expressible in the general form y = mxn, where x is time, n is some positive number greater than one, m is another positive number, and y is the state of the action at instant x. When n is 2, the readers will recognize the graph of the equation as one branch of the familiar square parabola, whose property it is to become parallel to the y-axis; i.e., to move at an infinite rate, in that never-never

Jan 1, 1947

By Eric Hedburg

This paper was originally prepared as a picture of the situation presented by the mining industry referred to at the end of the year 1899; and some of the descriptions and drawings of special mines, etc., may not completely show their condition a year later. The statements made as to the cost of mining and concentration, however, still hold good. As to other general statements made in the paper, it is believed that the following additional facts cover all that is required to complete them for the additional year. The condition of the mining industry in the Joplin district was better at the close of 1900 than at any time during several preceding years. Values seemed to have adjusted themselves, in considerable degree, to the commercial and technical circumstances, the cost of mining-supplies of all kinds had returned to a normal basis, and the product of ore found a ready sale,

Jan 1, 1902

By J. J. Bodmer

Although the similarity between puzzolana, or trass, and blastfurnace slag, as seen by comparison of the analyses, is a well-known fact, blast-furnace slag has not been used commercially as a substitute for those cementing materials. The reason, the writer apprehends, lies in the fact that unless such slag is disintegrated or subdivided by rolls, the process must either be too costly, or the material is not in a fit and proper condition for the purpose. In order to produce a reliable slag cement, the slag must be ground together with the lime into an impalpable powder. The subdivided slag must, therefore, be perfectly dry, and, at the same time, friable. The stronger the hydraulic properties of the lime, the more reliable the slag cement will be, and practice has proved, that the slag from a gray-iron furnace gives the best results. The slag cement which has given the results shown in the annexed table, under pressure tests, was composed of six parts of slag, from a blast-furnace producing No. 3 foundry iron, and one part of lime, of medium hydraulic properties. The above-described class of cement bears storing as long as most Portland cements, and the cheapness of its production is self-evident.

By Robert E. Brand, Strathmore R. B. Cooke

For a study of the bonding that occurs in magnetite pellets during oxidation, cubes of magnetite, hematite, and quartz were prepared, each with one surface polished and nearly optically plane. These faces were fired together under pressure and at various temperatures to determine whether bonding would occur. Sections of surfaces that bonded were examined microscopically. An attempt was made to measure the strength effected by this treatment. EARLIER work1,2 has shown that the strength developed by fired magnetite pellets containing silica or silicates is due to three separate effects. Two of these are associated with the formation of slag in the interior of each pellet at temperatures above 1000°C, where the atmosphere is substantially though temporarily neutral. The third is independent of the silica content and is responsible for the development of a hard shell around the pellet during the initial stages of firing, a condition which permits the pellet to assume the increasing load of the overlying burden and prevents extrusion of the slagged and semi-liquid interior. Pellets made from hematite concentrates do not show these effects unless specific additives are incorporated, and it is these differences in behavior which in large part account for the difficulty in producing satisfactory pellets from such concentrates. Elsewhere it has been stated that "the most important factor responsible for the development of strength in fired magnetite pellets containing no additive is the oxidation of magnetite to hematite and the subsequent recrystallization and grain growth of this constituent."' The object of the investigation reported in the present paper was to study in detail the mechanism described above and to evaluate its contribution to the strength of the fired pellet compared with other possible mechanisms, excluding slag bonding. This was effected by placing together polished faces of two cubes prepared from specific minerals and then heating them under constant pressure at different temperatures both in air and in nitrogen. The materials used were magnetite, hematite, and quartz. The magnetite was coarsely crystalline material from western Montana, the hematite was Itabira ore from Brazil, and the quartz was of optical grade but of unknown origin. A high-grade Lebanon (Pennsylvania) magnetite concentrate was used to prepare briquets for the investigation of bonding strength. Analyses of the iron oxide materials are given in Table I. The specimens for furnace treatment were prepared with a carborundum cut-off wheel, which cut the minerals into cubes approximating % in. along each edge. Care was taken to make the sides as parallel as possible. The edges of the faces to be polished were beveled, and the cubes were mounted in brass rings with sealing wax, this being essential to prevent the specimens from rocking during polishing. To prevent excessive friction, the wax was recessed so that only the brass ring and the face of each specimen would be in contact with the polishing lap. Each specimen was then ground with No. 600 carborundum to produce a level surface before polishing. The Graton-Vanderwilt process was not used for polishing because of the long time required by this method, but several other methods were tried. Cloth laps using levigated alumina or chromium oxide did not produce the desired polish. Satisfactory results were obtained by means of a pitch lap: which was used for all the mineral cubes, with levigated alumina as the polishing medium. The lap was operated in a machine similar to those used in the preparation of single optical surfaces. It was run at low speeds and moderate pressures, and polishing was stopped occasionally to prevent overheating of the lap. A good polish with flat surfaces could be obtained in about 5 min. After polishing the sealing wax was removed either in hot water or in a solvent such as turpentine.

Jan 1, 1955

By R. L. Robinson, P. DeFrank, R. F. Hatfield

Production equal to or greater than open-hole completions is possible through perforated completions if the flow paths throughout the perforations are free of obstructions.' Previous investigations have indicated that, in some cases, maximum productivity is not obtained due to plugging of the perforations with debris from the wellbore fluid and/or debris from the perforating process. Control of wellbore fluid and proper well completion techniques are very important in the elimination of perforation plugging.' Selection of properly designed perforating equipment also is quite important for maximum well productivity. Studies made with the use of the perforation flow laboratory, in which perforating tests are run under simulated well conditions, have shown that perforation plugging occasionally occurs. Plugs in perforations result from various causes. One of the contributors to plugging that can be controlled by the perforating device is the slug or carrot resulting from jet perforating. This condition has undergone extensive study, and previous developments have resulted in a decrease in carrot size—but not in complete elimination. It was felt that, if a method of completely eliminating the carrot could be found (with charge performance equal or better than previously obtained), a significant contribution would have been made. Such a charge has been developed and is reviewed in this paper. THEORETICAL CONSIDERATIONS OF CARROT ELIMINATION There are several popular theories of how a shaped charge jet is formed."," One of these is the hydrodynamic theory, wherein the liner is treated as a fluid under the impact of the explosive forces. Another is the spalling theory, where the interaction of shock waves in the liner causes small particles to be torn from the inner surface of the liner and projected at high velocity toward a common focal line to form the jet. It is not unreasonable to assume that both of these theories may be partially correct. For purposes of our discussion, it is simpler to use the second theory. Generally speaking, when a plate of metal is attacked by an explosive shock pulse, the pulse is transmitted through the metal at high velocity, as shown in Fig. 1(A). Pressures at the shock front may be 6 X 10' psi or higher. This shock wave (a compression wave) upon striking a free surface, Fig. 1(B), is partially reflected back as a tension wave. The interaction of the tension wave with the decaying compression wave causes a stress concentration in the metal; when this stress becomes great enough, a failure occurs and a small particle flies off and is projected away from the metal surface, as shown in Fig. 1(C). A new free surface is then presented to the shocks; the process repeats itself until there is no longer enough energy to cause failure, leaving a portion of the metal relativcly untouched. See Fig. 1(D). To apply this theory to a perforating shaped charge, consider the flat plate to be folded into a somewhat conical shape, with a column of explosive placed in intimate contact with the cone (Fig. 2). An explosive initiator detonates the charge, creating a shock wave

By P. J. Connors, William J. McCormick, F. B. Olender, Jerome F. Sheldon, Donald T. Mylar, Edgar T. Gregory, Owen S. Roberts, H. Colijn

A quiet revolution has taken place in the conveyor belt industry. Man-made materials, improved production facilities, better splicing techniques and emphasis on repair and maintenance have all contributed substantially to lowering material handling costs for the mining industry. Formerly the rubber industry had only cotton for a belt carcass and tree grown rubber for the protective cover. Monofilament rayon, with desirable elongation and elastic properties, was the first synthetic fiber to be used in place of cotton. But wet strength and other limitations restricted its use, and the conveyor belt industry turned to nylon.

Jan 3, 1972

By J. L. Wyatt

The electrical resistance of titanium as a function of purity and temperature was measured from —325" to 2800°F. Two points of inflection in the data plots were found, and an increase in resistance with increase in temperature above the transformation was observed. IN 1948 Greiner and Ellis' reported on the thermal and electrical properties of titanium, including a study of the effect of temperature on the electrical resistance. The materials used in the research were obtained from the United States Bureau of Mines, where powder metallurgy techniques were being employed for consolidation purposes. These authors found a decreasing resistance with increasing temperature above 1625°F, and concluded that the latter temperature represented the point of transformation from hexagonal close-packed to body-centered cubic structure on heating. They reported a specific resistivity value of 55x10-6 ohm-cm, and showed that dp/dt was positive, decreasing with increasing temperature above ambient. In one of his early texts Hume-Rothery2 mentioned that certain metals, including titanium, exhibited minima in plots of resistance vs temperature. He indicated that this occurred at 212°F. Reporting many years ago on the effect of temperature on the electrical resistance of zirconium, de Boer and Fast³ showed that phase transformation in this sister metal occurred over a range of temperatures, the extent varying with its purity. Graphs of resistance vs temperature, showing transformation effects over a range of several hundred degrees, were presented for relatively impure metal. In the latter case the resistance decreased with increasing temperature throughout the region of partial phase transformation, thereafter increasing as predicted for normal metals by modern theories of the solid state. Since the quality of metal used in previous studies was substandard compared with iodide-type titanium, and in view of the fact that there seemed to be some rather unusual observations in the reported literature, it was decided to undertake a more extensive study of the thermal effects using high purity titanium, and to include temperature ranges beyond those which had been studied in order to ascertain whether or not the characteristics of zirconium would be duplicated. Experimental Materials Materials used in this investigation included commercial quality titanium (Ti-75A produced by the Titanium Metals Corp. of America) in the form of ¼ in. diam rods, and high purity iodide titanium (produced by the Foote Mineral Co.) in the form of crystal bar of irregular size. The latter was cold-swaged into rod form and machined to the desired size. Lead wires to all specimens consisted of 18 gage Ti-75A. Chemical analyses of the stock materials are given in Table I. Experimental Procedures Specimens 2½ to 3 in. in length were prepared with diameters nominally 0.15 to 0.20 in. Two holes,

Jan 1, 1954

By B. H. Kear, H. G. F. Wilsdorf

After a few percent strain, dislocations in disordered Cu3Au are arranged in groups in ulell-defined slip planes, which contrasts with the more or less random distribution of dislocations in the corresponding ordered alloy. Unusually long and straigkt dislocation segments observed in the ordered alloy are interpreted in terms of cross slip of screw dislocations from their slip planes into cube planes. It is proposed that cross slip, and also dislocation reactions of the Lomer type, play an important role in work hardening of the ordered alloy. ACCORDING to to dislocations in the disordered lattice are only partial dislocations in the corresponding super lattice, so that in the super-lattice dislocations must occur as pairs, with each pair connected by a ribbon of antiphase boundary. Recently, striking confirmation of the theory was obtained by Marcinkowski, Brown, and Fisher3j4 in a study of dislocation configurations in thin foils of the Cu3Au alloy by transmission electron microscopy. In the present investigation, the observations made by these workers have largely been confirmed. Moreover, it has been found that dislocations in the plastically deformed ordered alloys are often unusually long and straight. This paper is mainly concerned with these new observations. A tentative explanation is offered in terms of cross slip of dislocations in the ordered alloys. PREPARATION OF SPECIMENS An alloy close to the stoichiometric composition Cu3Au was prepared by melting together high-purity copper and gold (99.995 pct) under vacuum in a graphite mold. The resulting ingot was rolled down and cut into strips 1 1/2 by 1/8 by 0.005 in. in thickness. All strips were annealed at 900°C for 3 hr and cooled to 500'~. A few of the strips were quenched from ~OO'C, while the remainder were slowly cooled in the temperature range 400" to 150°C at intervals of a few degrees every 24 hr to produce a high degree of order. After this annealing treatment the average grain size of the material was about 0.1 mm. Material in different states of order was obtained by reannealing fully ordered material at temperatures below the critical temperature: followed by quenching. The equilibrium degree of order attained at a particular reannealing temperature was obtained from the paper by Keating and warren.' A simple hand-operated tensile jig was used to give the strips the required amounts of plastic strain. Following straining, a number of specimens were cut from each strip by means of an electrolytic cutting device.= Finally, each specimen was thinned electrolytically using the polishing procedure described by Bakish and Robertson,7 and these thin sections were examined in the Philips EM-100B electron microscope operating at 100 kv. EXPERIMENTAL OBSERVATIONS Antiphase boundaries. The average domain size in the ordered alloys was found by direct observation to be about 0.25 p. Also, it was observed that the grown-in configuration of antiphase boundaries was changed little by plastic deformation, at least up to 6 pct strain. Fig. 1 shows an electron micrograph of a thin foil of partially ordered alloy (S - 0.8) after 3 pct strain. The micrograph shows a few dislocation pairs and a somewhat crystallo-graphic network of antiphase boundaries. The normal to this foil was found by diffraction analysis to be approximately 11121, with principal directions in

Jan 1, 1962

By John T. Galey

Oil and gas development in southern Pennsylvania during 1937 was marked by considerably increased activity in deep-sand drilling. Nine tests were completed to the Oriskany sand: one in Independence and three in South Beaver townships, Beaver County; one in Franklin township, Butler County, two in Slippery Rock township, Lawrence County; one in Mt. Pleasant township, Washington County, which is drilling below the Oriskany, and one in Fairfield township, Westmoreland County. Two of these wells, both of which were in the Blackhawk pool, South Beaver township, Beaver County, obtained wet gas with open-flow volumes of 1.5 million cu. ft. and 3.1 million cu. ft. and closed-in pressures of 1900 Ib. The remaining seven were unproductive in the Oriskany. Two wells, one in Hampton township, Allegheny County, which is shut down temporarily as a result of a gas pocket, and one in South Beaver township, Beaver County, are drilling to the Oriskany. One deep test on the Chestnut Ridge anticline, South Union township, Fayette County, was completed after considerable difficulty as a dry gas well in the Onondaga limestone. At this locality the cherty limestone is porous as a result of fracturing. Three additional tests are under way in the area, one in South Union township, a second in North Union township, and a third in Wharton township. Completions Oil.—Despite price cuts and production curtailment of Pennsylvania Grade crude, caused largely by a decreasing demand from export markets, operation in the shallow oil areas continued at a fairly high rate and a number of good wells were completed. Some of these were new wells in close proximity to old production and others were old wells drilled into deeper pays. One new well of a number of producers drilled to the Nineveh Thirty-foot sand in the Harvey pool, Center township, Green County, made 400 bbl. of oil and 500 million cu ft. of gas the first 24 hr. The Chambers dam pool of Amwell and South Franklin townships, Washington County, yielded a number of Fifth Sand producers with initials as high as 200 bbl. Several wells in the old Mars-Butler field

Jan 1, 1938