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By Richard L. Ashbrook, John F. Wallace

Several high-temperature eutectics of cobalt and nickel alloys were modified by small additions of selected elements. Thes-e alloys were compared to unmodified melts for microstructural variations. A few modified compositions were selected on the basis of structure and their tensile and stress-rupture behavior determined. The results of stress-rupture tests in air at 1800 F and room-temperature tensile tests of four high-temperature eutectics showed modification capable of producing substantial improvements in properties. The microstructures were altered and mechanical properties improved by: a.) dispersing a subordinate phase more uniformly throughout the matrix; b) replacing large continuous -network or platelike constituents with small equiaxed discontinuous phases; and c) by forming new, finely divided phases. tHE term "modification" is most commonly used to describe the refinement in microstructure of the Al-Si eutectic that occurs as a result of rapid cooling from the melt or on slow cooling after treatment with small amounts of sodium.1 "Modification" has also been used to describe the change from flake to spheroidal graphite in the austenite-graphite eutectic of cast iron.2 This change of graphite shape is accomplished by small additions of cerium or magnesium.3 Other systems have also been shown to be capable of modification, for example: Pb-Sn by copper;4 Al-Cu by sodium;5 Al-Mn by sodium;5 and Pb-Sb by aluminum.5 Although modification of Al-Si alloys and cast irons is usually accompanied by improved mechanical properties, a general definition of modification has been suggested to include the effect of small quantities of impurity elements on the microstructures of all eutectic alloys, regardless of the effect on the mechanical properties.6 In this paper, the term "modification" is employed in a broad sense to include the formation of third phases or even the supplanting of one of the binary eutectic phases by a third phase. The mechanism of modification, as for any solidification phenomenon, must be considered primarily in terms of nucleation and growth. Although both nuclea-tion and growth mechanisms are required to explain all the phenomena observed in connection with the solidification of modified eutectics, various investigators have usually favored one or the other.7"16 It has been shown that modification of a binary eutectic can be effected by addition of a solute element that has greatly different distribution coefficients or k values in the two phases of the eutectic. Under these conditions, differences in the temperatures at the solid-liquid interfaces of the two phases retard the growth of one phase with respect to the other.4 It has also been shown that increased undercooling favors a transition from a rodlike eutectic to a globular eutectic.17 A mechanism proposed for the transition from lamellar to rodlike eutectics depends on the concept of constitutional super cooling.18 The modification of eutectic alloys may be of interest for high-temperature service as well as at room temperature. Although "high-temperature eutectic alloys" may appear to be a contradiction in terms, many eutectic systems, including those studied in this work, have melting points in excess of 2400°F. One of the mechanisms by which high-temperature alloys are strengthened is dispersion of a relatively brittle phase such as an oxide, carbide, or an inter-metallic compound throughout a ductile matrix. For a given volume fraction of dispersed phase, strength is increased by decreasing the size and spacing of the dispersed particles.19'20 Furthermore, room-temperature ductility may also be increased by changing the shape of a brittle dispersed phase from platelike to equiaxed or spheroidal.8 Overaging and redissolving of the secondary phase limit the maximum temperature to which precipitation-hardened alloys can be used. However, in a binary eutectic system, both phases coexist up to the melting point. Although all eutectic structures are not completely stable,21 a dispersion-hardened cast high-temperature alloy might result if a fine distribution of one of the eutectic phases could be obtained during solidification. An additional reason for interest in eutectic alloys is their excellent castability.22 Since eutectic alloys, like pure metals, freeze at a single temperature rather than over a range of temperatures, their castability is superior to solid-solution alloys with long liquidus to solidus ranges. The purpose of this research was to study the effects of small solute additions on the microstructure and mechanical properties of a number of high-melting-point eutectic compositions.

Jan 1, 1967

By L. Zwell, H. A. Wriedt

In describing their procedure for measuring the lattice parameters of solid solutions, Abrahamson and Lopata report (p. 77) the final heat treatment of their alloy specimens as "700°C for 100 hr, followed by a furnace cool". The isothermal part of this treatment may be expected to precipitate solute in excess of the stable a solid-solution limit at 700°C; the subsequent slow cooling is likely to reduce the dissolved solute still further. Fig. 1 (upper) presents the data for titanium alloys so he;rt-treated and shows the lattice parameters of solid solutions containing up to 3.5 at. pct Ti; Fig. 17 (lower) shows 2 at. pct Ti as the solubility limit in a iron at 700°C. Figs. 1 and 17 are thus incompatible. The paper contains comparable incon~patibilities for zirconium alloys, for niobium alloys, and for tantalum alloys. The final heat treatment at 700°C may also be responsible for the anomalous "knee" in the lattice-parameter data for nickel alloys, Fig. 3. The "knee" composition is located near the 700°C limit of the stable a solid-solution field;37 alloys of the experimental composition range with more nickel than the "knee" composition are two-phase at 700 C and prolonged heat treatment of them at 700°C would tend to produce inhomogeneity rather than homogeneity. In Figs. 4 and 7, the composition ranges of the zirconium, hafnium, and niobium alloys examined terminate at alloy concentrations of 0.1 to 0.2 at. pct. These metals form very stable oxides and their partial removal from solid solution in iron by impurity oxygen may be expected. We believe that the authors should have reported the procedure by which they distinguished the amounts of alloying elements in solution and in oxide. The diagrams pertaining to copper in Figs. 3 and 18 (lower) are almost certainly incorrect. Three recent investigations of this system38-40 all substantially agree on the solubility of copper in a iron, finding it to be much larger than that reported by Abrahamson and Lopata. The change of the lattice parameter with composition reported by Abrahamson and Lopata is too large by a factor of three to five, as seen by comparison with the findings of other investigators.41738 Moreover, the authors violate, in Fig. 18, the accepted Fe-Cu constitution diagram37 by ignoring the eutectoid at about 850°C.

Jan 1, 1967

By Madan M. Singh

Although roof bolting has been a major means of strata support for nearly two decades, little attention has been directed towards the design of bolt Installations. The variables involved are interdependent and their study complex. However, some simple tests may be employed to serve as guides to the efficient design of roof bolt systems. Local conditions are continually varying and are important to pattern design. This paper discusses such considerations and suggests techniques which may be employed to effect improved roof control with bolts.

Jan 1, 1967

By R. T. Sorensen

Bench-scale and continuous testing were performed to adapt the anionic process for flotation of calcium activated silica to the fine-grained hematitic-goethitic jaspers from the Marquette range, Michigan. These ores typically contain about 35 percent Fe and require grinding to about 80 to 100 percent minus 400 mesh to insure an adequate liberation of gangue from the iron oxides. A method for removal of troublesome slime fractions without excessive iron loss, by first dispersing the quartz and then selectively flocculating the iron oxides, was evolved in the laboratory and successfully accommodated to pilot plant practice. The efficiency of the flotation process was improved with respect to both reagent usage and concentrate grade and recovery by using the selective flocculation-desliming technique as a pretreatment. The benefits of the combined desliming-flotation procedure were most evident in pilot plant processing. The best tests on two ores yielded recoveries of about 84 percent in concentrates containing 65.1 percent Fe and 4.8 percent SiO2 and 66.2 percent Fe and 3.9 percent SiO2, respectively. These results are in comparison to recoveries about 10 percent lower than the above to concentrates containing 63.9 percent Fe and 6.6 percent SiO2 in the one instance, and 63.6 percent Fe and 7.2 percent SiO2 in the other, obtained by flotation without the prior desliming treatment.

Jan 1, 1967

By C. R. Johnson, R. A. Greenkorn, E. G. Woods

A new method of reservoir evaluation called pulse-testins has been developed for describing formation properties between wells. Pulse-testing utilizes a sensitive differential-pressure gauge at a responding well to measure and record the response generated by a series of flow rate changes (pulses) at an adjacent or pulsing well. Since the pulse-test instruments have a sensitivity of about 0.001 psi, pulses of several hours or less in duration will generate a measurable response in most reservoirs. For this reason, many well pairs can be tested in a short period of time with little interference in field operations. Comparison of pulse-test results to conventional testing methods shows that the pulses obey unsteady-state, compressible-flow theory and thus provide a measure of both transmissibility (kh/µ) and storage (Fch). In additian, the method can be used qualitatively to describe communication across faults and between zones, and direction and tnagnitude of fracture trends. INTRODUCTION To obtain maximum usefulness of new reservoir analysis methods as well as to aid the field engineer in understanding local reservoir anomalies, improved methods are needed to describe heterogeneities in specific reservoirs. Optimum well spacing, equipment specifications, well completion design and especially the economics of pressure maintenance and secondary recovery programs depend on the extent and location of the heterogeneities that affect flow behavior in the field. One method for obtaining a measure of areal reservoir heterogeneity is an interference test. In the simplest interference test. constant-rate production or injection is initiated at one well and the effect of this flow is measured as pressure vs time at another well. Thus, during interference tests the flow characteristics of the formation are determined in situ. Despite their obvious usefulness in reservoir delineation. interference tests have not enjoyed frequent usage. Reasons for this have been the weeks or months required in many fields to obtain a pressure response measurable with conventional gauges, and the interruption of routine field operation during the field-wide shut-in normally required during these long times. Also, only average properties of the relatively large volume of the reservoir disturbed during these long times can normally be obtained — variations in properties between individual wells cannot be delineated. To eliminate these drawbacks of conventional tests, a special reservoir description technique called pulse testing' has been developed. Pulse-testing has several advantages that make it more convenient and practical for field use than interference tests. Valid tests are more certain because use of a series of flow disturbances gives rise to a diagnostic pressure response that can more readily be distinguished from unknown trends in reservoir pressure and other "noise." The time required is only a fraction of that for an interference test because a special, high-sensitivity differential pressure gauge can detect a much smaller pressure change. Variations in properties between individual wells can be delineated because of the relatively small volume of the reservoir disturbed during these short times. Finally, wells other than the pulsing and responding wells do not have to be shut in or carefully regulated.

Jan 1, 1967

By M. Vallée, J. -P. Charette, D. P. Gold

"The Oka Carbonatite and Alkaline Complex is a Lower Cretaceous intrusive body of the Monteregian petrographic province. Carbonate rocks of various types, and associated alkaline rocks of the ijolite and okaite suites, are distributed in a double ring-dyke structure 4 Yi miles long by 1 1/2 miles across. Alnoite and alrioite breccia pipes intrude all rocks of the Complex and indicate, from inclusions, that a cover of Palaeozoic rocks existed at the time of emplacement.The results of radiometric, magnetic and gravity surveys of the Complex are compiled and discussed both with respect to the regional pattern and, locally, the bed-rock geology. The Complex is characterized by high-intensity anomalies.Exploration activities started during 1953, and mining operations began in 1961 on the property of St. Lawrence Columbium and Metals Corporation, at one time the world's largest producer of niobium concentrates. Because of the boudinaged and fractured nature of many of the rocks and the variability in grade of the ore minerals, the role of the mining geologist is both demanding and exacting. Rock types are varied and their mutual relation-ships ambiguous, the minerals are rare and complex, and close geological control of the ore is needed in the mine and in the mill. Closely spaced diamond drill holes are needed for mining control, and the ore-waste contact is defined mainly by assay results.In the exploration for 'carbonatites' in Eastern Canada, aeromagnetic surveys are judged to be the best exploration tool, followed in decreasing order by the search for circular structures on aerial photographs, regional gravity surveys and radiometric surveys."

Jan 1, 1967

By M. M. Singh, J. W. Brown

Three rocks of highly varied physical properties are selected for the first reported experimental study concerning microseismic activity of rock under tension to determine the effects of static fatigue, loading rate, repeated loading and rock anistropy compared to compression and bending loads. The microseismic method of detecting rock under deformation may be a great potential tool in surveillance and location in situ of dangerously stressed strata, as well as predicting rock failures. Noises emitted under load or the rate of energy (energy of noise pulses generated per unit time) are computed for varying conditions. The tests are conducted at constant load on a dead weight loading machine to eliminate all possible extraneous noises — an indispensable precaution — at various load levels. Experimental results are reported including the relation of total energy emitted to tensile strength of rock and the possibility of simulating a phenomenological model for microseismic activity. Plots of some of the experiments are included. INTRODUCTION Rock failure, whether on a large scale faulting in the earth's crust and rock bursts in mines, or on small scale ruptures of laboratory test specimens, generates transient vibrations in the rock mass. Mechanisms of intermittent deformation, such as twinning and cracking through and between mineral grains, also produce similar vibrations, but of very small amplitude. Such vibrations from both deformation and failure are referred to as microseismic activity, rock noise, or occasionally seismo-acoustical activity. An individual rock noise is sometimes

Jan 1, 1967

By Lloyd E. Haight

After accepting the invitation to make this appearance today, it occurred to me that the subject matter which had been assigned to me, namely, the purpose and role of an advisor, was, contrary to what; some people might think, a controversial subject. In my brief lifetime, I have discovered that the world is full of advisors; that is to say, there are many people who undertake to render advice concerning subject matters upon which they may, or may not be qualified to speak. It shall be my purpose today to set forth what now appears to be the function of the members of the Advisory Council to the U. S. Public Land Law Review Commission; and, in so doing, I hope that I do not offend the Commission or any other-member of the Advisory Council with whom I serve. It has always been my personal conception of the role of an advisor that he should tender advice when it is requested, and then only if he has prepared himself concerning the matter upon which the advice is being given. I am sure it was the Congressional intent at the time the Public Land Law Review Commission was established indeed it was the hope. of Congress--that those of us who were to become members of the Advisory Council were informed upon certain particular subjects and then at the proper time express our opinions upon these subjects-and, by the same token, not attempt to enter opinions upon problems with which we have no experience in theory or in actuality. Some wag once said that if Columbus had had an advisory council, he would still be waiting at the dock in Spain, and there is more truth than fiction in that statement. With this problem in mind, let us examine the purpose of the Advisory Council itself.

Jan 1, 1967

By L. N. Cosner, C. F. Austin, J. K. Pringle

Shock wave attenuation studies with three igneous rocks are reported: a spessartite elastic to low intensity stress waves, a diorite which is anelastic, and a porous scoria. The level of shock passing through a given thickness of rock has been determined by donor-receptor methods using high speed streak cameras. Test results include shock propagation velocities adjacent to the explosive, the dependence of test results upon test geometry, and the variation in shock wave attenuation in these three common igneous rock fabrics. The utilization of explosives in rock mediums involves a series of interrelated phenomena. These are the detonation process within the explosive, the transfer of energy from the explosion products to the surrounding rock medium in the form of sound or shock waves, and the transmission of the resulting waves through the rock medium to create damage in the rock mass. The subject of this paper is the investigation of the close-in phenomena that occur in the intensely shocked rock immediately adjacent to a detonating explosive charge. The specific aspects studied include propagation velocities, free surface velocities, pulse attenuations and the determination of the equations of state for the test rocks employed. In addition, a series of tests was conducted to indicate the dependence of the test results on the charge diameter utilized. The equations of state for rock materials have been investigated by a number of authors. Lombard, ',' Grine and Fowles,3,4 Zharkov, 5 Hughes and McQueen,6 Chabai,7,8 and Bass9 have published equation of state data on rock materials similar in structure or composition to those investigated in the study. Rinehart10 has prepared a voluminous tabulation of the available equation of state data from these publications and in addition has included data on many other rock and earth materials in his compilation. The reader is referred to the extensive tabulations and bibliography of Rinehart for classical studies involving the equations of state of metals and other solids and liquids. The problems of sympathetic detonation between drill holes in hard rock environments has received the attention of various authors as have the problems of explosive rock coupling close-in stress wave attenuation and explosive diameter effects. 11 to 18 In particular, the don or-receptor geometry of this report is very similar to the geometry of adjacent drill holes in rock. Most published pulse velocity and attenuation work in rock has been devoted to velocities at much lower amplitudes than those associated with close-in explosives phenomena and most attenuation studies involve transmission and attenuation across large spans of material. Excellent work in these areas has been published by the U. S. Bureau of Mines and by many individuals and groups engaged in geophysical research. SELECTION OF TEST MATERIALS A series of rock materials was desired for this test program that would be meaningful industrially, and that would also yield comparative results from a research viewpoint. Based on the availability of a series of related petro-fabrics, for which there is an abundance of physical and shock response data, three igneous rocks were selected as the test series. The applicability of shock wave studies in igneous rocks to industrial problems is readily demonstrated. Hardrock tunneling, quarrying and mining take place in igneous rocks throughout the world. From a research point of view, igneous rocks exhibit a wide variety of grain sizes and considerable diversity in composition, yet the common igneous rocks have a general similarity in their constituent mineral structures and in their grain-to-grain bonding mechanisms. The latter is based on the concept of rock formation through magma cooling and crystallization, though the degree of liquefaction in granitic plutonic masses is indeed a moot question. Three specific types of igneous rock were chosen for study. A coarse-grained granitic textured rock was desired that would serve as a representative of the widely abundant intrusive rocks of the world and

Jan 1, 1967

By R. W. Boyle

"The concept of using chemical methods in prospecting dates back at least to the middle of the 16th century. Modern methods of geochemical prospecting, however, based on secondary haloes and utilizing trace-element techniques, were first practised in the U.S.S.R. and the Scandinavian countries in the 1930's. After 1945, methods based on soils, stream sediments and vegetation were rapidly developed in the U.S.A., the United Kingdom, Canada, France and other countries.The modern methods of geochemical prospecting owe their rapid development in the 20th century to the following:1.-Recognition of the primary and secondary dispersion haloes and trains that are associated with all mineral deposits. 2.-Development of accurate and rapid analytical methods utilizing the spectrograph and the various specific sensitive colorimetrie reagents, especially dithizone. 3.-Development of polyethylene laboratory ware of all types and the development of resins. This permitted greater freedom of field analyses and reduced the incidence of contamination.4.-Development of gas chromatography. This permitted the rapid and accurate determination of hydrocarbons in petroleum prospecting.Future research in geochemical prospecting should be focused on the following tasks: 1.-Definition of geochemical provinces and their relation to mineral deposits. 2.-Development of methods for discovering large low-grade deposits. 3.-Development of methods for discovering deeply buried deposits. 4.-Further development of methods to outline primary haloes. 5.-Eiucidation and formulation of techniques to relate the size and intensity of anomalies to the grade of the deposits. 6.-Development and refinement of biogeochemical methods, especially those based on indicator plants, chlorotic or toxic effects, and microbiological techniques. 7.-Definition of the types of primary and secondary haloes associated with accumulations of oil and gas."

Jan 1, 1967

By J. W. Spretnak, J. N. Cordea

The gain boundary relaxation in high-purity aluminum, nickel, copper, and silver was studied by means of a low-frequency torsion pendulum. Both internal friction and creep at constant stress tests were conducted. A lognormal distribution in relaxation times was found to account for the relatively wide experimental internal friction peaks and the gradual relaxation behavior during the creep tests. This distribution was separated further into a lognormal distribution of relaxation time constants and a normal distribution in activation energies. A spread of up to ±6 kcal per mole in the activation energies accounted for the major part of the distribution. A "double-peak" internal friction phenomenon was observed in silver. The activation energies in kcal per mole derived from the grain boundary relaxation phenomena are 34.5 for aluminum, 73.5 for nickel, 31.5 for copper, and 41.5 for silver. It was found that the rain boundary relaxation strength in these metals increases with the reported stacking-fault energy. GRAIN boundary relaxation phenomena have been observed in a large number of polycrystalline metals and alloys. Numerous investigations have been conducted to study the structure of the grain boundary through this relaxation process. One of the first investigators was Ke1-4 who observed that the activation energy for grain boundary relaxation in aluminum, a brass, and a iron was about the same as that for volume diffusion. He concluded that the grain boundary behaved as if it were a thin liquid layer with neighboring grains sliding over one another. Leak5 conducted experiments on iron of a higher purity and observed that the grain boundary activation energy is comparable with that of grain boundary diffusion. He suggested that, in metals where this relationship holds, the damping may be caused by a reversible migration of grain boundaries into adjoining grains. Nowick6 has presented an interesting view of inter-facial relaxation with his "sphere of relaxation" model. A relaxed interface is represented as one where the shear stress is greater than the normal value along the edges and zero in the interior of the interface. The region of the stress relaxation is pictured as a sphere surrounding the interface. From his calculations Nowick concluded that the slip along an interface is directly proportional to its length. Therefore, the time of relaxation, T, depends on the size of the relaxation interface. This means that in the Arrhenius relationship, t = TO exp[H/RT], valid for atom movements, the relaxation time T is predicted to be proportional to the grain diameter through the pre-exponential term, TO. Since the internal friction can be given as Q-1 = ?j wt/(1 + w2r2), where ?J is the relaxation strength and w is the angular frequency, an increase in grain size at a constant frequency will shift the peak to a higher temperature. A great deal of work has been done to determine the exact relationship between the internal friction and grain size.1,5,7,8 In metals, the grain boundary peaks are found to be lower and broader than predicted theoretically.' The above model can explain this by a distribution in the size of the interface areas, represented by a distribution in the parameter tO, and an overlap of spheres of relaxation, represented by a distribution in activation energies. Both these phenomena result in an over-all distribution in the relaxation time, which could affect the internal friction peak height, breadth, and also position. This relationship between the experimental data and theoretical calculations appears very promising in the study of interfacial relaxation mechanisms. THEORY A lognormal distribution in t can sometimes be used to adequately describe the spectrum of relaxation times governing an anelastic relaxation. wiechert9 originally suggested such a distribution to explain the elastic after-effect in solids. This choice is particularly applicable to grain boundary relaxation when considering Saltykov's work.'' He found a lognormal distribution in the grain sizes within a metal. Recently Nowick and Berry11 have introduced a log-normal distribution in T into the theoretical internal friction equations. The form of the distribution function is where z = In(r/rm), and Tm is the mean value of t. The parameter ß is a measure of the distribution and is the half-width of the distribution when is l/e of its maximum, IC/(O). Nowick and Berry have described the methods to obtain the parameters Tm, ß, and ?,J from experimental internal friction and creep test data. In the idealized case, where only one relaxation event occurs with one relaxation time, only ?J and T are necessary to completely describe the event, and 0 = 0. For the broader internal friction curves 6 is some positive number greater than zero. The larger the 6, the greater is the half-width of the distribution in In t.

Jan 1, 1967

By Emmanuel P. Papadakis

Ultrasonic velocity measurements have been made to study the preferred orientation in cube-textured copper. Methods applicable to thin specimens were employed since the specimens were necessarily of sheet material. The measured velocities in various directions in the sheet differed from the corresponding values in single-crystal copper by 1 to 6 pet. The distribution of the deviations indicated that the align-ment of the (001) planes with the rolling plane was better than the alignment of the [100]and [010] directions with the rolling and transverse directions. Ultrasonic pole figures (velocity us orientation) are shown to be useful in the study of preferred orientation. THIS paper describes one set of experiments in a continuing study of preferred orientation in worked metals. This study has been undertaken to investigate the fundamental properties of metals when used as propagation media for ultrasonic waves. Many such materials are of current or potential use in ultrasonic delay lines. Fundamental studies on ultrasonic propagation parameters such as velocity, attenuation, and diffraction (beam spreading) are of importance in the design of delay lines, in the development of nondestructive testing methods, and in the study of materials themselves. Preferred orientation in worked poly-crystalline metals influences all three above-mentioned parameters, and hence is of particular importance. When polycrystalline metals are subjected to mechanical working, they develop textures dependent upon their crystal structure and the symmetry of the working operation.' The texture consists in the alignment of the crystallographic axes of the grains in preferred directions with respect to the symmetry axes of the working operation. Since the grains are elastically anisotropic, the elastic moduli of worked metals are anisotropic. Hence the velocities of elastic waves in worked metals depend on the directions of propagation and polarization. The worked metal may be thought of as taking on the elastic symmetry of a single crystal: so it possesses the same number of independent elastic moduli as the crystal class it simulates. In general, a worked metal does not adopt the crystalline symmetry of its own grains. For instance, most rolled sheet becomes effectively orthorhombic while all bar stock and wire develop hexagonal symmetry. However, certain metals with cubic crystal structure develop a cube texture upon rolling and annealing.= Nearly perfect alignment of [100]-type directions with the rolling direction, transverse direction, and rolling-plane norma1 can be achieved in certain fcc metals and alloys. These cube-textured rolled metals provide an excellent opportunity to test preferred orientation by means of elastic waves, since a worked metal with 100 pct cube texture would have elastic moduli identical to the moduli of its constituent metal. It is the purpose of this paper to present the results of an investigation upon cube-textured copper. Ultrasonic waves were used. The methods of measurement and the experimental results on the effective moduli will be given. The ultrasonic measurements will be shown to complement X-ray pole figures for the determination of preferred orientation in worked metals. EXPERIMENT To study cube - textured material, it was necessary to use thin-sheet material since a severe reduction in gage (95 to 99 pct) is necessary to produce cube texture. Special ultrasonic methods were needed to investigate the thin material at megacycle frequencies. A) Materials. The cube-textured material tested was a copper alloy containing 1 pct Zn. Specimens already measured for Young's modulus4 by Alers were kindly supplied by him. The specimens were slabs 3.00 by 0.25 in. cut from sheet 0.047 in. thick. The orientations of the long axes of the specimens with respect to the rolling direction were taken in 15-deg steps from 0 to 90 deg. B) Measurements. Two distinct experiments were performed to measure the phase velocity in these specimens. One measured the shear wave velocity for propagation in the 0.25-in. direction and polarization in the 3.00-in. direction. The other measured the velocity of both shear and longitudinal waves propagating in the thickness direction in the sheet. 1) Plate-Mode Measurements. The velocity of the zeroth-order shear mode5 was measured in the 0.25-in. direction in each strip. The specimens were ground thinner over half their length to assure that the first-order shear mode would be cut off below 6 Mc per sec, leaving the zeroth-order nondispersive shear mode as the only propagating mode. Piezoelectric ceramic transducers of 5 Mc per sec resonant frequency poled in their long direction were solder-bonded to the edges of the thin part of the slabs as in Fig. 1 after these edges had been made flat and parallel by fine grinding. These transducers produced waves polarized in the 3.00-in. direction and propa-

Jan 1, 1967

By Yoichi Ishida, Ching-Yao Cheng, John E. Dorn

Tile creep behavior of a iron was investigated over the range of temperatures from 375° to 1150°K. Apparent activation energies for creep, obtained by the effect of sudden changes in temperature on the creep rate, revealed the presence of- four distinguishable regions. The creep behavior of a iron in Regions II (480° to 774°K) and 111 (775° to 1045°K) was found to correlate well with a model where the creep rate is controlled by the nonconsevualive motion. of jogged screw dislocations. An anomalous increase in the apparent activation energy fur creep in Region III was found to be in harmony with the known decrease in the free activation energy for self-diffusion over the Curie transformation range. Furthermore, the creep rates in Regions II and III were found to increase with stress due not only to the effect of stress on the activation energy but also to an increase in density of mobile dislocations. The evidence suggests that pipe diffusion along moving dislocations could be a significant factor over the lower temperatures of Region II. ALTHOUGH the creep properties of iron and steel have been of interest to metallurgists for some time and an extensive literature is now available, most of the published information has not produced much toward understanding the fundamental dislocation processes controlling the creep behavior of these materials. Whereas the activation energy for high-temperature creep of metals usually agrees well with that for self-diffusion, Sherby, Orr, and Dorn1 deduced from the data of Tapsell -and c1enshaw2 that the activation energy for creep of Armco iron is about 78,000 cal per mole and more recently Lytton and sherby3 reviewed the data of Jenkins and Mellor4 and found an activation energy for creep of a iron of 80,000 cal per mole. Both values are substantially greater than the activation energy for self-diffusion in a iron. Because of the limited data suitable for purposes of identifying the controlling dislocation mechanisms of creep and the unusually high activation energies for creep quoted above, it was considered desirable to reinvestigate in detail the creep of a iron by more reliable techniques which would provide sufficient data for determination of the creep mechanisms. EXPERIMENTAL TECHNIQUE Creep specimens were prepared from 3/8 by 4 in. iron bar stock of the following composition by weight percent: 0.001 C, 0.0120 0, 0.001 N, 0.004 S, and 0.003 P. The as-received bars were cold-rolled to a thickness of 0.100 in., annealed under argon for 30 min at 1113°K, cold-rolled to a final thickness of 0.063 in., and machined into tensile specimens having gage section 0.250 in. wide and 1.70 in. long. Finally they were recrystallized under argon at 1113°K. Specimens to be crept above 1060°K were recrystallized at 1173°K. Both recrystallization treatments gave the same reproducible equiaxed ASTM No. 4 grain size. Creep testing was conducted in machines fitted with Andrade-Chalmers arms that maintained a constant stress to within ±0.2 pct of the reported values. Deformation over the specimen gage section was sensed with a linear differential transformer and recorded auto-graphically as a function of time. The strains deduced from these measurements were sensitive to ±5 x 10-5. During creep the specimens were contained in an argon-filled chamber which was immersed in a temperature-controlled molten tin bath. Creep temperatures, as measured by thermocouples attached to the specimen, were maintained to within ±10.25°K of the reported values. For activation-energy determinations rapid changes in temperature of about 12°K were obtained within 30 sec by direct resistance heating of the creep specimen, and maintained to ±1°K of the reported values. Observations of structural details of specimens before and after creep tests were made by electrolytic polishing and etching in acqueous ammonium persulfate. EXPERIMENTAL RESULTS A typical example of the determination of apparent activation energies, Q, by the effect of small changes in temperature is illustrated in Fig. 1. Q is defined by

Jan 1, 1967

By G. E. Wittur

"The twenty-one members of the Organization for Economic Cooperation and Development, comprising eighteen western European nations plus Canada, the United States and Japan. account for two-thirds of world steel production. The Special Committee for Iron and Steel was formed by the OECD to study trends and problems in the steel industries of member countries. The paper begins with a summary on the Organization, including an historical sketch, its structure, member-ship and objectives. The steel industry of the entire OECD is briefly described before proceeding to a more detailed discussion of various aspects of the steel industries of European OECD members, emphasizing practices and conditions that differ from those in North America. Benefits to Canada of representation at meetings of the OECD Special Committee for Iron and Steel are described."

Jan 1, 1967

By M. A. Upham

"MINING is Canada's second largest basic industry, producing material with a gross value of 2.5 billion dollars, led only by agriculture with 2.9 billion dollars. It pro-vides employment, directly and in-directly, for three quarters of a million people. Since the Second War, the value of mineral production in Canada has tripled. Economists forecast that over the next 15 years its value will triple again. Canada is a basic and leading supplier of nickel, iron, copper, zinc, lead and uranium. It is also a major oil producer, leads the world in the production of asbestos and in five years will be the leading producer of potash, a basic constituent of fertilizer.It can be seen that Canada's wealth and economic progress lies in being a primary producer of economic minerals and in building secondary industries to manufacture finished products from these raw materials. Canada's future in the field of mineral production looks bright, with our resources just starting to be tapped. Outside of the large expanse of Soviet Russia, we are by far the world's most fertile mineral exploration area."

Jan 1, 1967

By M. C. Makepeace

"It is the objective of designed experiments to obtain more information for less material and process cost than can be obtained by traditional experimentation. In this paper, the fundamental concepts on which the statistical design of experiments is based are briefly re-viewed according to the following outline: The Experiment The Design The Analysis Two simple 2"" factorial experiments are presented as examples."

Jan 1, 1967

By Donald B. Hunter

The Ti-Be system up lo 10 wt pct Be with cortlmercialll' pure titanium has been determined using metal-lographic techniques. Beryllium forms the p eutec-toid type of dinqarz with titanium; the eutectoid occurs at 0.5 xt pct Be azd 1500 F, while an eutectic is foritled at 1887°F containing between 5 and 7.5 rt pct Be. The solubility of beryllium in a titanium does not exceed 0.05 zvt pct and the maximum solubility of Beryllim in 0 titanium is 1 wt pet. PREVIOUS work on the Ti-Be phase diagram indicated that additions of beryllium to titanium resulted in a marked lowering of the melting point,''' and it was also observed that the solubility of beryllium in both a and p titanium was retricted.- With the limited data available, McQuillan and McQuillan constructed a partial hypothetical diagram of the Ti-Be system,= assuming that beryllium formed the 0 eutectoid type of system with titanium. Subsequently Bedford published a tentative diagram of the entire Ti-Be system: although he did not investigate alloys containing less than 10 wt pct Be. This diagram included several compounds described by other authorities.'-l3 The following account describes work directed toward determining the form of the titanium-rich portion of the phase diagram up to 10 wt pct Be. MATERIALS AND METHODS Titanium sponge and a master alloy containing 25 wt pct Be were used in the formulation of the alloys; the chemistry of these materials is detailed in Table I. The alloys were prepared as 250-g compacts which were melted into buttons by arc melting under purified argon on a water-cooled copper hearth. Results of analyses for beryllium are shown in Table I but no determination of other elements was made at this stage. The alloys were hot-rolled at 1650°F to produce 0.1-in.-thick sheet. Alloys containing up to 1.5 pct Be were fabricated without trouble; samples containing 2 pct cracked initially upon hot rolling, but thereafter rolled satisfactorily to sheet. The 5, 7.5, and 10 pct were hot short and could not be rolled. Surface contamination was removed from samples by sandblasting and pickling in a 5 pct HF-35 pct HNOs solution. For metal log raphic examination, heat-treated specimens were mounted transverse to the rolling direction, ground on silicon carbide papers of increasing fineness to 600 grit, and electropolished at 20 v using a solution containing 600 ml of methanol, 60 ml of perchloric acid, 360 ml of butyl cellosolve, and 2 ml of Solvent "X". Difficulty was experienced in obtaining good electropolished surfaces with samples containing more than 1 pct Be, the degree of difficulty in-

Jan 1, 1967

By J. P. Morris

The Bureau of Mines investigated the mechanics of fuming of iron-carbon melts during top-blowing with oxygen. Melts weighing 45 lb were prepared in an induction furnace and blown with oxygen by means of water-cooled lances. The rate of fuming was measured and correlated with the operating variables. The data showed that the primary cause of fuming was a boil at the bath surface in the impingement zone of the oxygen jet. Nucleation of the carbon monoxide bubbles producing the boil was apparently brought about by the precipitation of an oxide phase. The actual fuming mechanism involved partial oxidation and vaporization of bubble films and fine metal spray generated by the bursting of the bubbles. Bubbles that formed outside the impingement zone produced little fume. The distribution of trace elements between the metal and fume strongly indicated that the fume contained fine spray particles as well as particles that had condensed from vapor. The rate of fuming was found to be proportional to the carbon content of the metal) the concentration of oxygen in the jet) and the bath temperature) provided that a continuous boil occurred. In the absence of a boil) very little fume was produced.

Jan 1, 1967

By Bernard Porter

The rate of the heterogeneous reaction between reactor-grade yttrium and lithium fluoride in lithium fluoride-yttrium fluoride mixtures was measured using a quartz spring balance. At 950° C the magnitude of the rate of reaction is 10-5 grams of yttrium/cm2-sec. The heat of activation for the reaction is 38.3 kilocalories per mole of LiF. A surface-controlled mechanism is proposed in which LiF is adsorbed on the yttrium metal surface. An activated complex is formed when additional LiF reacts with the adsorbed LiF-metal site. The activated complex then decomposes to the products) which are lithium metal and YF3. The importance of the reaction in the electrowinning of yttrium metal from fluoride electrolytes is discussed.

Jan 1, 1967

By Maurice Lauzon

"Aerial surveys of the open pits have been conducted regularly at Lake Asbestos of Quebec, Ltd. -a subsidiary of American Smelting and Re-fining Company -since 1958. Ground controls are supplied by Lake Asbestos, and a topographic map of the pits at a scale of 1 in. to 50 ft., with 2-foot contour intervals, is obtained by aerial photography. The information from the topographic map is then transferred by the Lake Asbestos engineering staff to sections from which the volumes removed are calculated. Considering the size and complexity of the operation, this system has proved to be the cheapest, fastest and most accurate way of determining the quantities of rock and overburden removed. More than 11,000,000 tons of ore and waste are mined each year in three different pits. Further-more, the nature, shape and extent of the orebodies make it necessary to mine on many (up to eight) benches of a pit during a single year. In addition, there are sections of the pits where it is impossible or un-safe to survey the crest of some benches by standard ground methods. For these reasons, the tonnages obtained by truck count are checked and adjusted by aerial survey. These surveys are now taking place every six months. With this system, it is possible for a two-man surveying crew to look after all field work in the mine area."

Jan 1, 1967