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By Samuel Daniels

The Al-Cu-Ni-Mg alloy is much benefited by heat treatment and, in such condition, is preferable to the Al-Cu-Fe-Mg alloy either as cast or as heat-treated, when both are reheated to temperatures of from 400" to 600" F. and compared, cold, with respect to strength and to hardness. The main differences between the alloys do not arise until the reheating temperature exceeds 400" F., above which they gradually soften. This softening is characterized metallographically by the appearance of intragranular precipitate. The Al-Cu-Ni-Mg alloy is weakest and least hard after being reheated at 600" F., the Al-Cu-Fe-Mg alloy at about 700" F. The former starts to reharden at 700" F., the latter at 800' F. There is a tendency for both alloys to lose strength and hardness with prolongation of time at the reheating temperatures of 500" and of 700" F. The Al-Cu-Ni-Mg alloy is considerably stronger and harder than the Al-Cu-Fe-Mg alloy when both are heat-treated and reheated for long periods of time at 500" and 700" F. Although the latter can be made harder initially than the Al-Cu-Ni-Mg alloy by suitable quenching and aging, heat treatment, in general, favors the retention of this initial (strength and) hardness after reheating to a much greater degree in the Al-Cu-Ni-Mg alloy. The percentage of elongation of the two materials in any condition is very small. Certain aluminum alloys have been used for pistons and other parts operating at temperatures up to 650" F. because of their lightness, high thermal conductivity and specific heat, fair strength and hardness at elevated temperatures, excellent machineability, and moderate resistance to corrosion. In the piston, the inertia forces and the bearing loading, and with this the vibration, are decreased. The piston head functions at a lower temperature (about 200" F. below one of cast iron), so that, because of the lessened tendency toward carbonization and detonation, higher compression ratios may be used. On the other hand, the aluminum alloys do not have the wearing and bearing qualities of cast iron; also they have a large coefficient of expansion, allowance for which must be made in the design. The range in analyses of aluminum alloys, used for pistons in domestic and in foreign internal-combustion engines is shown in Table 1. There seem to be three general types of composition; one containing about 10

Jan 1, 1926

By J. P. Witherow

The plant of Messrs. Oliver Brothers and Phillips, the only one in operation until January, 1886, has not been available for any further experiments since those of Mr. R. W. Hunt, described in his paper on the subject, at the Chattanooga meeting. Continuous working has, however, led to important improvements in plant, and furnished valuable results in practice. The difference between the converter and plant of 1884, as illustrated in our Transactions, vol. xiii., p. 759 and following pages, and those of 1885, may be observed in Plates 1. and 11. accompanying this paper. Plate I. gives the elevation and plan, in half-section, of one of our latest 3-ton converters. Plate 11. gives a plan of the general arrangement of a plant adapted to turn out slabs, blooms, and billets for the general market. The letters on Plate I. refer to the following parts :

Jan 1, 1886

By Waldemar Lindgren

Jan 1, 1905

By B. C. Allen, W. D. Kingery

Surface tension and its temperature dependence have been determined for pure liquid Fe, Cu, Co, Ni, and Sn and for Fe-C, Co-C, and Ni-C alloys. The temperature coefficient of surface tension is negative for all these liquids. The surface tension and wetting behavior of tin and tin-titanium alloys on A120,, Si,N,, MoSi,, and Sic, as well as the behavior of titanium-containing nickel alloys on A1 20, have been determined over a wide temperature range. For all the solids investigated titanium additims markedly lower the contact angle. Some limits for the solid-surface energies have been calculated from liquid surface tension and wetting behavior. SURFACE tension and interface energy are important variables in a number of metallurgical and ceramic phenomena, and have been discussed at some length in connection with determining micro-structure of polyphase systems,' solid-state sintering,' thermal etching of grain boundaries, heats of solution and fine powders,'1 grain-growth phenomena,' the mechanical behavior of fine foils and fibers, nucleation, soldering and brazing,' and other phenomenz of academic or practical interest However, until recently few quantitative data have been available for high-temperature systems. Among available data are some indicating positive temperature coefficients for the surface tension of liquid copper,*,11,'2 cast iron,l3 and iron-carbon14 alloys. Although carbon was found to be not surface active in iron at 1570" some preliminary studies had indicated the possibility of a positive temperature coefficient for the eutectic composition at lower temperatures.16 One part of the present study has been largely concerned with determining the temperature coefficient of surface tension for several metals at elevated temperatures, In addition to surface-tension studies, the wetting behavior of alloys containing titanium has been investigated over a wide temperature range. Previous measurements indicated that titanium was selectively adsorbed from nickel at a liquid nickel-solid alumina interface,17 and the use of titanium hydride or titanium-alloy techniques for metal-ceramic soldering is well known. In the present study, previous data have been extended to new alloy systems, and measurements have been carried out with other oxidation-resistant ceramics. EXPERIMENTAL The sessile-drop method was employed to measure liquid surface tension and contact angle between liquid and solid, utilizing apparatus and techniques which have been described previously.'g The shape of a sessile drop depends on equilibrium between forces of surface tension tending to form a spherical surface of minimum area and forces of gravity tending to flatten the drop. Typical sessile drops are shown in Fig. 1. From precise measurements of maximum drop diameter and drop height the surface tension and drop volume were calculated. Four solid materials were employed as supporting plaques for the liquid-metal drops. Aluminum oxide (99.9 pct, J, T. Baker, reagent grade) was pressed and sintered at 1800°C. Molybdenum-disilicide powder (99.0 pct, Electro Metallurgical Co.) was pressed and sintered at 1650°C. Plaques were cut from silicon carbide (99.4 pct, hot-pressed at Alfred University) and silicon nitride (95.1 pct, with Al, Fe, 0 as major impurities, Norton Co.) rods. All plaques were polished, cleaned, and dried prior to use. A number of metals and alloys were employed. Chemical analyses of vacuum-melted ingots of iron, nickel, cobalt (National Research Corp.), commercial nickel-base alloys, electrolytic copper (International Smelting and Refining Co.), and tin (Mal-linckrodt Chemical Works) are given in Table I. Alloys were prepared in the laboratory by vacuum melting the base metal with either titanium hydride (Metal Hydrides, Xnc.) or spectroscopic-grade carbon (National Carbon Corp.). Nickel-titanium alloys contained between 0.001 and 0.005 pct oxygen and the ferromagnetic metal-carbon alloys contained 0.001 pct. Cylindrical metal specimens (1 to 2.5 g) were machined and bevelled at the bottom to insure a uniform advancing contact angle on melting. Before use the samples were acid-etched, cleaned with acetone, and rinsed in petrol ether.

Jan 1, 1960

By B. A. Cheadle, K. P. Steward

Axial tensile, ring tensile, closed end burst, and free end burst tests were done at room tempe.vature and 300°C on three batches of Zircaloy-2 sheathing zuith different textures. Knoop hardness tests were also done on all batches. The mechanical properties of the tubes were largely dependent on the percentages of cold work, but were also markedly affected by the textures, particularly with respect to deformation behavio'r. The deformation behavior observed confirmed Picklesimer's predictions, zuhereas Knoop hardness results could be correlated with texture and yield strength anisotropy after the ,method of Wheeler and Ireland. From the mechanical properties, and from efjectiue strain values deterrlzined at the fractures using a photoqid technique, it zuas concluded that tubing witlz a single preferred orientation of radial basal poles best combines strength and ductility for any given deqee of cold work. THE mechanical properties required in collapsible Zircaloy-2 fuel sheathing for water-cooled power reactors are strength to resist wrinkling deformation by coolant pressure and ductility to accommodate a small amount of deformation in service without rupturing. Zircaloy-2 tubing during fabrication develops pre- ferred orientations of the a Zr grains due to aniso-tropic deformation behavior, and these textures markedly affect mechanical properties. Picklesimer' had predicted the deformation behavior of tubes with various textures, but the texture required to provide the optimum strength and ductility for a given degree of cold work has not been reported. To investigate this problem, tests at three transverse to axial stress ratios were done at room temperature and 300°C on three batches of Zircaloy-2 tubing covering a wide range of textures and percentages of residual cold work. Knoop hardness values were also measured to correlate with preferred orientation and yield strength anisotropy after the method of Wheeler and relland.' 1) MATERIAL For this investigation, three batches of tube-reduced tubing were chosen from the Zircaloy-2 sheathing produced for the Douglas Point Reactor. Individual tubes were 191/2 in. long, 0.600 in. OD, and 0.0165 in. nominal wall thickness. The identities of the batches, together with their textures, are shown in Table I. The tubes had the normal Zircaloy-2 composition3 of 1.5 wt pct Sn, 0.3 wt pct Fe, Ni, Cr combined with the following oxygen concentrations: Batch VII 1140 to 1390 ppm 0 Batch VIII 1400 to 1750 ppm 0 Batch IX 880 to 1320 ppm 0

Jan 1, 1968

By A. Kelly, S. Sato

Tensile tests have been performed on aluminum single crystals of 99.99 pct purity at 196°K. The resolved shear stress when the stress-strain curve becomes concave to the strain axis depends on orientation, being always higher for crystals with an initial orientation close to the sides of the unit triangle. Observations have been made, with the optical microscope, of the appearance of slip lines on polished surfaces of the crystals. Particular attention has been paid to the first appearance of cross-slip. It is confirmed that marked cross-slip is first seen when the stress-strain curve becomes concave to the strain axis. Measurements are reported of the lengths of the slip lines observed on top and side faces of the crystals at various stages of the deformation. The lengths of the slip lines vary inversely as the flow stress for all crystals, independent of crystal orientation. From measurements of the lengths and separations of the slip traces it is possible to estimate the number of dislocations which are annihilated at each cross-slip site. It is concluded that the annihilation of screw dislocations of opposite sign is the most important cross-slip process occurring. FRIEDEL1 recently pointed out that the stress-strain curve of many pure metals of face-centered-cubic structure can be considered as composed of three stages. Plastic flow commences with a region showing a small rate of hardening which is approximately linear. This has been called "easy glide*. It is followed by a region of more rapid hardening in which the slope of the curve is again approximately constant and this, in turn, is superseded by a final part of the curve which is concave to the strain axis. Following Diehl2 we may designate these regions as stages I, II, and III respectively. The onset of stage 111 occurs at lower stresses at higher temperatures. The appearance of the slip lines formed during these various stages has been described by a number of workers?-5* The object of the present work was to make detailed observations of the lengths and separations of slip lines for a number of crystals of different orientations deformed at the same temperature and strain rate. Although much previous work has been published on the deformation of aluminum single crystals the importance of measurements of these quantities has only recently been realized—they are essential for experimental tests of recent theories of work hardening.' 9 In aluminum, deformed at room temperature, stage 11 of the stress-strain curve is very weakly marked, as the stress for the onset of stage 111 is attained soon after the end of easy glide. In the present experiments it was decided to use a temperature lower than room temperature so that stage II of the curve was better developed. However, at temperatures as low as 90°K slip lines are not measured easily with the optical microscope.5 For this reason 1960k was chosen as a suitable temperature. Even at 1960k however, stage III of the curve commences at glide strains of 6 to 10 pct and hence

Jan 1, 1960

By Frederick N. Rhines, William A. Anderson

The investigations of Wymanl have demonstrated that copper deoxidized with several of the commonly used agents that confer immunily to ordinary hydrogen em-brittlement can still be embrittled if it is annealed alternately under oxidizing and reducing conditions. During the oxidizing cycle, oxygen diffuses into the copper and frequently deposits a subscale composed of the oxide of the residual deoxidizing agent. Upon subsequent reduction with hot hydrogen, the copper becomes ruptured along the grain boundaries to a depth sharply limited by the previous penetration of oxygen as delineated by the inner boundary of the subscale. Obviously the sensitivity to this kind of hydrogen embrittlement is engendered by the introduction of oxygen during the oxidizing anneal, but beyond this the mechanism of the process, and hence the controlling factors, remain obscure. There are several possibilities: (I) oxygen dissolved in the copper matrix of the subscale may, upon cooling prior to the hydrogen anneal, precipitate as cuprous oxide which is subsequently reduced by hydrogen as in the familiar case of hydrogen embrittlement; (2) oxygen in solid solution in copper may itself confer susceptibility to embrittlement by hydrogen; (3) the normally refractory oxides such as those of aluminum, silicon and titanium may themselves be reduced by hydrogen when in contact with copper; or (4) the precipitated oxides of the subscale may be complex compounds such, perhaps, as SiO2.Cu2O, which are partially reduced by hydrogen. These possibilities have been examined, and it has been concluded that the first three and possibly the fourth are operative collectively or individually under more or less predictable conditions. Effect OF Precipitated Cuprous Oxide and Dissolved Oxygen The literature provides no definite proof that oxygen in solid solution in copper can confer susceptibility to hydrogen embrittlement; indeed, the research of Leiter2 seemed to indicate the opposite—that to produce the effect, cuprous oxide must be present in massive form and in a more or less continuous network along the grain boundaries. To test this point, pure copper has been annealed in hydrogen under conditions designed to ensure the presence in various samples of: (I) precipitated cuprous oxide, (2) dissolved oxygen only, and (3) no oxygen in any form. Very pure copper" said to contain no oxygen and no spectro-scopically detectable traces of any other element (that is, no individual detectable impurity in quantity greater than 0.0001 per cent) was used. Strips of this material cold.-rolled 75 per cent to 1/8 in. in thickness were subjected to the following treatments, the results of which are noted:

Jan 1, 1941

By Frederick N. Rhines, William A. Anderson

The investigations of Wymanl have demonstrated that copper deoxidized with several of the commonly used agents that confer immunily to ordinary hydrogen em-brittlement can still be embrittled if it is annealed alternately under oxidizing and reducing conditions. During the oxidizing cycle, oxygen diffuses into the copper and frequently deposits a subscale composed of the oxide of the residual deoxidizing agent. Upon subsequent reduction with hot hydrogen, the copper becomes ruptured along the grain boundaries to a depth sharply limited by the previous penetration of oxygen as delineated by the inner boundary of the subscale. Obviously the sensitivity to this kind of hydrogen embrittlement is engendered by the introduction of oxygen during the oxidizing anneal, but beyond this the mechanism of the process, and hence the controlling factors, remain obscure. There are several possibilities: (I) oxygen dissolved in the copper matrix of the subscale may, upon cooling prior to the hydrogen anneal, precipitate as cuprous oxide which is subsequently reduced by hydrogen as in the familiar case of hydrogen embrittlement; (2) oxygen in solid solution in copper may itself confer susceptibility to embrittlement by hydrogen; (3) the normally refractory oxides such as those of aluminum, silicon and titanium may themselves be reduced by hydrogen when in contact with copper; or (4) the precipitated oxides of the subscale may be complex compounds such, perhaps, as SiO2.Cu2O, which are partially reduced by hydrogen. These possibilities have been examined, and it has been concluded that the first three and possibly the fourth are operative collectively or individually under more or less predictable conditions. Effect OF Precipitated Cuprous Oxide and Dissolved Oxygen The literature provides no definite proof that oxygen in solid solution in copper can confer susceptibility to hydrogen embrittlement; indeed, the research of Leiter2 seemed to indicate the opposite—that to produce the effect, cuprous oxide must be present in massive form and in a more or less continuous network along the grain boundaries. To test this point, pure copper has been annealed in hydrogen under conditions designed to ensure the presence in various samples of: (I) precipitated cuprous oxide, (2) dissolved oxygen only, and (3) no oxygen in any form. Very pure copper" said to contain no oxygen and no spectro-scopically detectable traces of any other element (that is, no individual detectable impurity in quantity greater than 0.0001 per cent) was used. Strips of this material cold.-rolled 75 per cent to 1/8 in. in thickness were subjected to the following treatments, the results of which are noted:

Jan 1, 1941

By Arthur B. Cummins

Mineral fillers are employed in United States industries to the extent of more than seven million tons annually, valued in excess of a hundred million dollars. This substantial usage involves a wide variety of mineral materials. To this may be added products manufactured from minerals, such as carbon black, portland cement, lime or chemically precipitated calcium carbonates, which would add substantially to the total. The purposes for which fillers are used differ considerably. Minerals used as fillers are mostly silicates, silicas, and carbonates as referred to hereinafter. The term "mineral filler" has various meanings in mineral technology and in the arts. Fillers are comparatively inert and their action is mainly physical. Materials that are employed primarily for chemical reactivity, or for pigment or abrasive functions ordinarily would not be considered to be fillers when used for these purposes. Nearly all filler usages are based on advantages which are gained by desired modification of composition properties or by improvements in processing. A simple definition for a filler is an inert material that is included in a composition for some useful purpose. This definition may be amplified or made more specific for each of the filler usages, the major ones of which are: paints, paper, plastics, rubber, bituminous compositions, pesticides and fertilizers. There are in addition a whole host of minor usages. Powdered minerals when employed as components in paints, varnishes and lacquers are considered as extender pigments or low refractive index pigments. In paper, the term loading material as well as filler is used; in pesticides, the terms diluents and carriers connote different functions. For bituminous compositions, rubber and plastics, the usage of the simple word "filler" is more usual, but the designation loading material is sometimes used. Minerals Used as Fillers Most of the industrial minerals, and many rock powders are employed to some extent for different filler uses. These usages vary from year to year depending on availabilities, costs, technologic trends and advancements. For the major applications, however, and for the more particular requirements at any given period, there are general trends which favor a more or less restricted group of filler products for each of the major consumer fields. This selection of materials is determined by the characteristics of the individual filler products, their effectiveness in fulfilling the primary function or functions for which they may be employed, and the cost after incorporation in the finished product. The mineral-bearing materials of major importance as fillers are: limestones, clays of several types, talc, pyrophyllite, mica, barite, diatomite, crystalline silicas, asbestos, slate and other rock dusts. Others of secondary importance include: gypsum, vermiculite, phosphate rock, perlite, and pulverized wastes, such as slag and fly ash. A considerable number of other minerals are used to lesser extent. Among these minor mineral materials are: feldspar, pumicite, wollastonite,18 tripoli, nepheline syenite,6 coal, altered volcanic rock and others.2 Indeed, most mineral materials, when reduced to fine particle size may have some potential usage as fillers, depending on their properties, availability and price. On the other hand, the more exacting filler requirements

Jan 1, 1960

By Giovanni Barla, Stefan H. Boshkov

This paper examines the application of gelatin mixture models to the study of factors such as gravity effects, tectonic and residual stresses, anisotropy, physical nonlinearity, time-dependent behavior of the rock mass and connectedness of the geologic space. The technique of calibrating gelatin mixtures proposed by Richards and Mark in 1966 is applied to the particular problem considered. Similitude relationships between model and prototype are discussed with reference to the constitutive equations describing the physical behavior of the rock mass. The interaction between two openings in a linearly elastic medium, under conditions of plane strain, is used as an illustrative example with the view to describing the history of stress and deformation changes on the rock medium and lining around a slusher drift while undercuts are made in block caving. The prediction of the displacement, stress field and mode of fracture associated with a given rock structure, its initial stress field, and its physical properties is essential to rock mechanics and ground control. The basic approach is to assume the rock mass to behave as a continuous, homogeneous, and isotropic medium. The classical theory of elasticity is the simplest theory based on such a concept. Specification of the elastic constants, the initial state of stress in the ground, and the boundary conditions on stress and displacement allows one to predict stress and displacement within the body. Subsequently, provided that a criterion which governs rock fracture under various stress conditions has been established, a stability analysis of the rock structure can be performed. A natural extension of the present knowledge consists of removing some of the simplifying assumptions which characterize the analytical solutions based on the classical theory of elasticity. Complex geometry, the significance of tectonic and residual stresses, anisotropy, physical nonlinearity, time-dependent behavior of the rock mass and connectedness of the geologic space are some of the important factors which are neglected in the classical approach. A better insight into the real problem can be attained with either the finite element method of stress analysis or an experimental technique. The former has already been applied with success on several occasion 1-4 and is destined to render great service in the field of rock mechanics and ground control. The latter, which will be considered in this paper, has been used extensively in applications too numerous to be enumerated. Experimental technique involves either prototype testing, if the area to be studied is accessible, or model testing. Two- and three-dimensional photo-elastic analyses are very convenient means of obtaining the stress distribution in models of complex geometry. In general, such analyses are confined to studies of stress fields around openings which are sufficiently far removed from the surface boundary so that the stresses in their neighborhood are practically equal to those produced by an initial uniform stress field; i.e., so that gravitational effects are negligible. There are, however, many rock structures where these effects must be taken into account to attain a more realistic representation of the problem. Surface and near surface rock structures, systems of openings interacting with one another, and structural components loaded only by their own weight are some of the obvious examples. This paper was written to show how factors neglected in the usual analysis based on the classical theory of elasticity, can be taken into account when gelatin mixture models are used inconjunction with photoelastic methods. The interaction between two openings in a linearly elastic medium, under conditions of plane strain, is used as an illustrative example, with a view to describing the history of stress and deformation changes on the rock medium and lining around a slusher drift while undercuts are made in block caving. The birefringence of gelatin mixtures has been known for some time. A series of experiments were carried out by Rossi in 1910,5 but after that very

Jan 1, 1970

AIME 1953 DIRECTORY SUPPLEMENT OFFICERS AND COMMITTEES OF LOCAL SECTION; COUNCIL OF SECTION DELEGATES Linwood Thiessen, Chairman H. D. Vaughan, Vice-Chairman John H. Melvin, Secretary EXECUTIVE COMMITTEE L. E. Thelin, Connecticut J. B. Cunningham, Arizona W. L. Penick, San Francisco G. L. Yates, Kansas DELEGATES Adirondack - C. DeWitt Smith '54 Alaska - Robert 11. Chapman, ?54 Arizona J. B. Cunningham, '53 Black Hills - Sidney M. Runke, '54 Boston -R'. Schuhmann, Jr. ?54 Carlsbad Potash - W. P. Wilson, '54 Central Appalachian - Charles T. Holland, '54 Chicago - H. A. White, '54 Cleveland - Milton Tilley, '54 Colorado - J. Paul Harrison '54 Columbia - Harold Kirkemo, '54 Connecticut - Lewis E. Thelin, ?53 Dallas - Kenneth F. Anderson, '54 Delta - Roy S. Sullins '54 Detroit - F. P. Bens, '53 East Texas - Joseph A. Morris, '54 El Paso Metals - E. M. Thomas, '54 Florida - W. O. McClintock '54 Fort Worth - Ray Elner, '51 Gulf Coast - H. E. Treichler, '53 Kansas - G. L. Yates, '53 Lehigh Valley - H. R. Gault '54 Lima, Peru - R. P. Koenig, ?54 Lou-Ark - A. H. Crawford. '53 Mexico - W. G. Kane, '54 Mid-Continent - J. H. Beesley, '53 Minnesota - J. R. Stuart, '54 Montana - F. W. Strandberg, '53 Nevada - Albert Silver,'53 New York - P. Malozemoff, '54 North Pacific - A. H. Mellish, '54 North Texas - K. F. Anderson, '54 Chio Valley - J. H. Melvin, ?53 Oklahoma City - Charles Miller, '53 Oregon - T. C. Matthews, '54 Penn. Anthracite - D. C. Helms, '54

Jan 1, 1953

By Joseph G. Debanné

Foreword The three case histories and the liquid fuels planning scenario presented in this paper span a twenty year period, from the pioneering days of computers in the petroleum producing industry during the mid-fifties, to the energy crisis era of the seventies. Inasmuch as two of the main actors, Ian McKinnon and I, are featured in all three case histories, while I am currently involved in the fossil fuels scenario, this paper provides four related and personal spot readings along an evolutionary path: from the one dimensional technical domain to the multi-dimensional techno-socio-economic domain of computer applications in the petroleum industry. Coincident with this evolution in the direction of increasingly comprehensive and powerful computer applications, the evolution in hardware/software capability and in analytical power are also kept in perspective. The three case histories are: 1. The Bonnie Glen-Wizard Lake Case (Calgary, Alberta, 1955-1957); 2. The TransCanada-Great Lakes Gas Transmission Case (Ottawa-Washington, 1966); 3. The Westcoast Transmission - El Paso Pipelines Gas Export/ Import Case (Ottawa-Vancouver-Washington, 1966-1967). The liquid fuels planning scenario is a demonstration exercise rather than a case history; however, it represents an important point on the evolutionary curve and, provides a concrete example of tech-

Jan 1, 1977

Jan 1, 1908

By H. H. Smith, G. J. Danek, M. R. Achter

Nickel, Type 316 stainless steel, and copper show decreases in reversed bending fatigue strength with increases in air and oxygen pressure. The leveling off of the log N us log p curve for nickel at 300" and 816°C is discussed in terms of a model in which surface saturation gives rise to a critical pressure. A metallographic study indicated that the effect of environment on crack initiation and growth rates is a function of temperature. It is shown that small amounts of impurities in inert gases may substantially reduce the fatigue strength of nickel. 1n a previous investigation1 of high-temperature bending fatigue in air and in vacuum, reversals in the effect of environment with changes in test conditions were atrributed to a mechanism consisting of two processes acting in competition. One of them, oxidation strengthening, has been demonstrated in a straightforward manner by measuring the rupture strength of a sintered nickel-oxide bond.' The detailed operation of the other process, facilitation of crack propagation by surface absorption of oxygen, is uncertain. Thompson et UZ advanced the possibility that the formation of an oxide layer prevented rewelding of cracks during the compressive part of the cycle, while Wads worth and Hutchings4 further proposed that the reaction of oxygen with atoms at the tip of the crack helped the metal to break there, a possibility which has also been advanced to explain crack formation in creep.5 A difficulty in arriving at a mechanism for this lowering of fatigue strength in air is the inconsistency of some of the data. For example, Wadsworth and Hutchings4 found an approximately linear decrease of log cycles-to-fracture (N) with an increase of log pressure-of-air (p) for copper and aluminum at room temperature, while snowden,' although finding a similar linear dependence for aluminum, observed a stepped curve for lead. Between l0-' and 10"1 torr there is a sharp decrease in the fatigue life of lead with increasing air pressure, but plateaus, signifying no dependence on pressure, are found at higher and lower pressures. If, as discussed elsewhere: these environmental effects arise from the adsorption of gas on crack surfaces, it would be expected that as the pressure is increased a saturation point would be observed, beyond which there is no further effect. To gain further information about the form of the log N vs logp curve, it was decided in the present investigation to repeat this type of measurement at elevated temperature on nickel, copper, and Type 316 stainless steel. An additional object of this program was

Jan 1, 1963

By Charles Miller

Natural carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mcxico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid curbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended. The Farnham anticline is used as an example and computations are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. Introduction Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1938

By Charles Miller

Natural carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mcxico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid curbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended. The Farnham anticline is used as an example and computations are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. Introduction Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1938

By S. F. Emmons

It was said by many who discussed Professor Posepny's admirable paper on the "Genesis of Ore-Deposits," read at the Chicago meeting of the Institute, in 1893, that its most valuable feature was the clear distinction which it drew between the influence upon ore-deposits of the " vadose " circulation of waters descending directly from the surface, and that of the deep underground circulation of waters generally coming from the depths, and assumed by the author to be ascending through more or less open spaces under the influence of heat. A little later the effect of the oxidizing action of the vadose circulation upon ore-deposits was ably and exhaustively treated by Prof. R. A. F. Penrose, in a paper on " The Superficial Alteration of

Jan 1, 1901

By Richard D. Hagni

Mississippi Valley-type ore deposits contain significant quantities of minor elements, which are present partly in the form of separate mineral phases and partly in solid solution in the major sulfide phases for which these deposits are exploited. These elements, as separate phases, are: copper, mainly in chalcopyrite and enargite; cobalt and nickel, chiefly in thiospinels and bravoite; rare earth elements associated with certain fluorites; and native gold. Many economically important minor elements occur in solid solution in sphalerite, including silver, cadmium, iron, germanium, gallium, indium, thallium, cobalt, nickel, and mercury. Significant amounts of silver and antimony, and perhaps very small amounts of gold, are present in solid solution in galena. Chalcopyrite may contain small amounts of silver, molybdenum, bismuth, cadmium, cobalt, and nickel. Marcasite and pyrite may contain silver, thallium, cobalt, and nickel. Although some of the minor elements contained in the Mississippi Valley-type deposits are currently recovered at the smelters and refineries, many are lost in tailings, sludges, and slags; consequently, important quantities of these elements are potentially recoverable as non-conventional resources.

Jan 1, 1983

By Malcolm Wilson

THE year 1923 was one of great importance in northern Louisiana and southern Arkansas, so far as the' development and expansion of previously discovered oil and gas fields were concerned. However, the search for new fields failed to produce a single discovery that led to important development during the period; in this respect, the year was one of discouragement to the prospector. During the winter and spring months, an especially active "wildcat" campaign was in. progress in southern Arkansas, and a large number of tests were drilled in northern. Louisiana but this activity subsided during the summer and fall. By the close of the year, only routine drilling was in effect in the fields; and only two new areas-Cotton Valley, in Webster Parish, and an area in Union Parish, La.-were showing any important activity because of favorable oil showings. Further drilling is contemplated in both of these areas, and the present feeling is that one or the other may produce the next oilfield in this territory. Briefly, the development of the Smackover field was the overshadowing event of the year. In. southern Arkansas, important development also took place in the East El Dorado, Stephens, and Irma fields; but all of these were relatively small. In northern Louisiana, many new oil wells were drilled in the Bellevue field, and many new gas wells in the Monroe field. In the old Caddo field, a large number of the deep Woodbine wells were plugged back to the "chalk rock," where a high gravity oil is obtained. In the other fields, only a few small wells were drilled. Therefore, Arkansas, furnished the real development of the year in this area. The production for the year showed a material increase over that of 1922, due, chiefly, to Smackover, and practically altogether to the Arkansas fields. In Louisiana, every field, except Caddo, Bellevue, and Elm Grove, showed slight to marked declines; while in Arkansas, El Dorado was the only field that declined throughout the year.

Jan 3, 1924

By Robert S. Archer, Zay Jeffries

It is about fifteen years since the development in Germany, largely by Alfred Wilm, of the aluminum alloy called duralumin. In this alloy, combining as it does the tensile strength of mild steel with the lightness and corrosion resistance of aluminum, a distinctly new material was presented to the engineering world. Despite the evident usefulness of this material, however, its commercial development has been slow, due in part to the difficulties involved in its fabrication. In view of the potentially great utility of strong aluminum alloys, it seemed desirable to find means of producing such alloys with better fabricating properties, and work was undertaken with this object in the laboratories of the Aluminum Company of America several years ago. This work has resulted in the production of two new types of aluminum alloy of the "strong alloy" class, having distinctly improved fabricating qualities. The knowledge gained has also made it possible to produce alloys of the duralumin type with greater strength and hardness than previously obtained. There have thus been made available some new engineering materials which it is the object of this paper to describe. These alloys, induding duralumin, are fundamentally wrought alloys. Castings of the same compositions heat treated in the same manner give inferior physical properties, particularly as to ductility. The statements made subsequently concerning properties and heat treatment apply to material that has received sufficient working to thoroughly break down the cast structure. The material referred to has, in general, undergone a reduction in section of at least 80 per cent, by mechanical working. It may be mentioned in passing that other compositions have been found that are suitable for the production of the maximum physical properties in heat-treated castings.

Jan 1, 1925