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By R. H. Frazier, J. M. Hodge, F. W. Boulger

This paper reports the results of studies of the impact properties of quenched and tempered alloy-steel plates as a function of sulfur content. It was found that the impact energy levels decreased continuously as the sulfur content increased and that there was a straight-line relationship between impact energy and sulfur content when plotted on logarithmic coordinates. Cross rolling raised the level of these Lines for transverse tests and lowered the level for logitudinal tests proportionately to the amount of cross rolling. ALTHOUGH it has been generally recognized that, for applications in which notch toughness is critical, the sulfur content of the steels used should be held to a low value, quantitative information on the effect of sulfur on notch toughness has not been available. For such applications, it is a common practice to specify minimum impact values, and in order that these may be met consistently it is important that the steel producer know quantitatively the effect of sulfur on notch toughness so that realistic sulfur content limits can be applied to the steels they produce. In many instances, particularly in flat-rolled products, impact properties are specified in the direction transverse to the principal rolling direction, so that the factors affecting the anisotropy or directionality of impact properties are also of concern to the steel producer. For some applications, furthermore, it is a common practice to increase the sulfur content of steels in order to improve their machinability, and, in such instances, the effect of this practice on notch toughness may often be of concern. This paper reports on an investigation, carried out at Battelle Memorial Institute, designed to furnish this quantitative information on the effect of sulfur on notch toughness and also to furnish further information on the factors affecting the anisotropy of impact properties in wrought heat-treated alloy steels. MATERIALS AND EXPERIMENTAL PROCEDURE The experimental steels were of intended base analysis: 0.30 pct C, 0.80 pct Mn, 0.25 pct Si, 2.5 pct Ni, 0.80 pct Cr, and 0.45 pct Mo. Steels were made with sulfur contents varying from 0.005 to 0.179 pct. The steels were prepared from 600-lb induction-furnace melts. Steels containing 0.020 pct or more sulfur (at meltdown) were melted from a charge of ingot iron (except for one heat): lower-sulfur steels were made from electrolytic iron. The charge consisted of ingot or electrolytic iron, ferrosilicon to give 0.10 pct Si, and ferromanganese to give 0.05 pct Mn. At meltdown, electrolytic nickel, ferromolybdenum, iron phosphide, and pyrite were added followed in sequence by ferrochromium, sili-comanganese, ferrosilicon, and ferromanganese. The slag was then removed and graphite added to give the desired carbon content. Bath temperature was adjusted to 2850°F and, when no other additions were to follow, 2 lb per ton of aluminum was added, immediately before tapping. Compositions of the experimental steels appear in Table I. Analyses are from single determinations, except sulfur which was analyzed in duplicate. A test sample (3 in. in diam by 6 in. long) and a 575-1b ingot were poured from each heat. The test sample was poured in a sand mold; the cooling rates of the test sample and the large ingot were approximately the same. Chemical analysis chips and metal lographic specimens were taken from the test samples. The ingot was 8 in. sq at the base and 9 in. sq at the top. A 5 X 5 X 6-in. sand mold hot top was completely filled in teeming the ingot. After solidification, the mold was stripped from the ingot which cooled to room temperature. Ingots were reheated to 2250"F and rolled to 1.9-in. slabs on a commercial mill. The slabs were box-cooled to room temperature. Sections of the 1.9-in. slabs were heated to 2250°F and rolled on a Battelle laboratory mill according to one of three schedules: 1) rolled straightaway to 0.5-in. plate; 2) rolled straightaway to 1.3-in. thickness, then cross rolled to 0.5-in. plate (29 pct cross rolling); or 3) cross rolled from 1.9-in. to 0.5-in.-thick plate (46 pct cross rolling). The 0.5-in.-straight- or cross-rolled plates were normalized at 1700°F for 1 hr and then water quenched from 1600°F. Plates were then tempered 2 hr at 1240°, 1170°, 1080°, or 860°F to obtain Rockwell C hardness of 25, 30, 35, and 40, respectively. Tempering was followed by quenching to room temperature to avoid temper embrittlement. Slack-quenched plates were isothermally transformed for 26 min at 800°F, quenched, and tempered 2 hr at 1170°F. Pearlitic microstructures were obtained by holding 168 hr at 1200° F, followed by quenching. Charpy V-notch specimens were taken both transverse and longitudinal to the main rolling direction, notched perpendicular to the plate surface, and tested. Slabs and plates which were to be homogenized

Jan 1, 1960

By Linney, Robert J.

REPUBLIC Steel Corporation's iron-ore properties in the Adirondacks consist of mines, mills, and sintering plants in the Mineville and Port Henry area and at Lyon Mountain. This article will deal with the properties in the vicinity of Mineville and Port Henry. In 1938, when Republic leased the Mineville- Port Henry operations from the Witherbee Sherman Corp., these properties had just come through some hard depression years. As a result, the mine development program was far behind schedule; most of the equipment needed replacement; and above all, the entire system of mining had to be completely changed to reduce operating costs. The concentrator had been in operation for many years; the process was dry and dusty. Machinery and equipment were either badly worn or entirely obsolete. The sintering plant, also long in operation, was badly in need of repairs.

Jan 1, 1943

By C. H. Li, R. D. Carnahan, R. J. Stokes, T. L. Johnston

When silver chloride deforms by pencil glide at temperatures of 26ºand 72°C, grain size has no effect upon the proportional limit and the material necks down to a knife edge under tension. At -196ºC, deformation takes place on fewer slip systems to produce straight slip traces, the flow stress becomes sensitive to grain size and fracture occurs by cleavage from an intergranular source without any reduction in area. THERE are significant differences between the appearance of the slip bands formed in silver chloride and in the alkali halides at room temperature. The bands in sodium chloride, e.g., are fine and geometrically straight, whereas in silver chloride they are coarse and wavy.' Such differences in the slip behavior prompted us to inquire what the effects of grain boundaries might be on the mechanical properties of these solids. As an introduction to a general study of ionic poly-crystal behavior, we have investigated the effect of grain size on the stress-strain relationships in silver chloride at different temperatures. We have chosen silver chloride chiefly because polycrystals can be easily prepared free from cracks and macroscopic voids by conventional techniques. Moreover, as we shall see, the slip behavior can be readily modified by changing the temperature. It will be shown that the effect of grain size on the yield stress of silver chloride is strikingly dependent upon the temperature of deformation and that this temperature effect comes about through a change in the number of slip systems which operate at the onset of plastic flow. EXPERIMENTAL PROCEDURES Polycrystalline tensile specimens were made by recrystallizing cold-rolled AgCl sheet. Thirty-gram quantities of AR grade silver chloride powder were melted in a low heat capacity furnace, cast into cylindrical forms 3/4 in. in dim and approximately 1 in. in length and then extruded with a 16:l reduction ratio into rods 3/16 in. in dim. Extrusion temperatures were varied from room temperature to 350°C. In order to impart various degrees of cold'work to the extruded rod. All extrusions were then cross rolled to sheet 0.040 in. in thickness at room temperature and machined to form tensile specimens having a gage length of 0.750 in. with a width of either 0.250 or 0.145 in.* Annealing was carried out in an air oven at 200°C for periods up to 20 hr. specimens having average grain diameters ranging from 0.024 to 0.40 mm were prepared by varying the extrusion temperature and annealing time in the conventional manner. To obtain specimens with grain sizes larger than 0.40mm, lightly deformed thin prisims of silver chloride single crystals (supplied by Harshaw Chemical Co.) were recrystallized. Grain size determinations were made by an intercept method and revealed that the grains were equi-axed. Laue back-reflection X-ray patterns showed little tendency to form a preferred orientation texture. Specimens which were to be used for the slip band studies were polished by immersion in fresh boiling concentrated NH,OH for 60 sec. They were then etch polished for 10 sec on each side by hand lapping on a stationary velveteen lap wetted with a dilute Hypo solution (5 g of Kodak Acid Fixer in 100 cc H20). Finally the specimens were rinsed in warm water and alcohol, blown dry and carefully mounted in the tensile machine for testing. Tensile tests were performed at three temperatures, namely, 26º, -72º, and -196°C. A screw-driven hard tensile machine was used at a constant strain rate of 0.006 in. per in. per min. Loads were determined with a light- proof ring fitted with A-18 strain gages and extensions were measured with a 0.0001 in. dial gage. Constant level baths of alcohol with dry ice and liquid nitrogen were used to maintain the two lower test temperatures. EXPERIMENTAL RESULTS Reproducibility—In view of the light sensitivity and reactive nature of silver chloride, it was necessary to determine whether reproducibility depended upon either exposure to light or to the condition of the surface. However, during the course of the work it became clear that variation of laboratory lighting

Jan 1, 1962

By E. N. Harshman

Uranium mining and milling are rather new industries in Wyoming and South Dakota, but, in the past 15 years, ore valued at more than $400,000,000 has been mined and milled in the region. The major uranium deposits are in structural and/ or erosional basins or on the flanks of uplifts. The principal host rocks are medium- to coarse-grained sandstones that were deposited in continental or brackish-water environments and were derived in large part from the granitic cores of the uplifts and the sedimentary rocks that flank the cores. The ages of the host rocks range from Cretaceous to Miocene, but more than 95 per cent of the known reserves in the region are in rocks of early Eocene age. The bulk of the ore in the region is unoxidized and lies below the water table; some oxidized ore has been mined in the Powder River Basin and Black Hills districts. The unoxidized ore comprises pyrite, uraninite and/ or coffinite, marcasite, hematite, jordisite(?), and selenium. Minerals in the oxidized ore include hydrous uranium carbonates, phosphates, and sulfates and hydrous uranium and/ or vanadium silicates. The deposits are in the form of ore rolls that contain from a few hundred to a few hundred thousand tons of ore, ranging in grade from 0.1 per cent to 1.0 per cent U3O8. The rolls are at the margins of large tabular bodies of sandstone that has been altered by the orebearing solutions. The deposits are believed to have resulted from the interaction of an alkaline; oxidizing, ore-bearing ground water and a reducing environment. Exploration guides include the spatial relations of ore to altered sandstone, favorable lithology in the host rock, the content of certain elements and/ or compounds in ground water, and the relation of deposits to major paleodrainages.

Jan 1, 1968

By Leon Orlowski

THE oil-bearing districts of Poland are found on the slopes of the Carpathian Mountains. The oil belt extends from Gorlice southeast to Stanislawow. It is approximately 250 miles long and 30 miles wide, and comprises four geological districts: the western, or Gorlice district; next, to the east, the Krosno district; the Boryslaw district; and, in the extreme southeast, the Stanislawow district. The amount of petroleum produced in Poland from the beginning of the oil industry scarcely totals 26,000,000 metric tons, or 15 per cent. of the estimated supply. Of this amount, 18,000,000 tons have been taken from the fields of Boryslaw within 25 years; and only about 8,000,000 tons from all other fields within a period twice as long, although some of these other fields represent just as good possibilities as did Boryslaw at the beginning of its development. The Polish oil industry was severely stricken by the war. The retreating Russian armies, in 1915, destroyed a large number, of the existing oil wells, nor was the post-war period favorable for the development of this industry;; the money and credit stringency interfered with the expansion of drilling. But since 1921 there has. been a slow steady increase in production and there is now every reason to believe that conditions in the industry will improve. In fact, an increase in new drillings has been reported for the current year. The production of crude oil in Poland, in 1913, amounted to 1,113,668 metric tons. In 1914, the production declined- to 655,600 metric tons. In 1921, the production was 705,596 tons; in 1922, 712,428 tons, and in 1923, 737,182 tons; or more than 5,000,000 bbl. But the fields have a much greater potential output, which could be realized were the capital available for prospecting and new drilling. The principal producing, and at present most exploited, fields are around Boryslaw and Schodnica. These fields were developed rapidly for in the first year of their modern exploitation the wells were gushers of moderate depth. However, as a result of heavy drilling, the shallow folds have been exhausted and oil can be reached now only by deep drilling. Wells of almost 5600 ft. have been drilled in Boryslaw. Because of these drilling conditions, a large number of engineers and workmen specially skilled in deep drilling are to be found in this field.

Jan 3, 1925

By George T. Hansen

WHY try to find oil in Utah? Why try to find oil anywhere? Isn't there too much oil already? Answers to these questions involve general oil conditions but are pertinent to my subject. In the first place oil produced in Utah up to the total amount of local consumption would not be subject to nor concerned with the national oil situation. An oil field in this State capable of producing up to 15,000 bbl. per day would have a large value and prompt realization. In the sec¬ond place, there is not too much oil nationally although the markets have been upset temporarily from time to time. Petroleum is so necessary and is in such general demand that an oil field anywhere, anytime, is a valuable and live asset. The oil business in general shows the best condition of any major industry. It has never been hit as hard as most industries and 1932 was a large improvement over its low spot of 1931. It can be and probably will be the one to lead the country back into business stability. Consumption of its products has been reduced less than that of any other important commodity. There are good and valid reasons why it should have been making a normal profit continuously. It has the oil and the processes and the facilities and the policies and the consumption of its products. There is only one reason why it has not been profitable recently and that is the lack of intelligence of from five to ten per cent of the producers. An op¬erator lacks intelligence when he cannot see that it is better for him to sell one barrel of oil at $1 than two or three barrels at 25 or 35c. per bbl.

Jan 1, 1933

By M. L. Requa

This paper is abstracted from the report of the Appraisement Committee of the Independent Oil Producers' Agency, of which the writer was Chairman. The other members of the committee were M. V. McQuigg and R. S. Haseltine. To Thomas Cox, engineer in charge of the investigation, and to his efficient staff of assistants, is due the credit for the detail work necessary in carrying out the plan of the Committee. It treats only of the valuation of the lands, wells, and piping, without going into details of equipment and other features. It was recognized, early in the operation, that the value of oil lands was the value of oil ,to be extracted and marketed, less the costs attendant thereon. Referring this back to the costs in cents per barrel, it became obvious that surface improvements, absolutely necessary in the production of oil, from wells then drilled, had no separate and independent value aside from the value of the land, but that any excess equipment, not necessary for the production of oil from present wells, such as drilling tools, well casing, etc., should be given a present condition value. In valuing the properties of the Independent Oil Producers' Agency, the Committee has considered the following facts: 1. That from each property there will ultimately be produced a certain total quantity of oil. 2. That in the production of that oil a certain total quantity of money will be expended. 3. That a certain total amount of money will be received from the oil. 4. That the total net receipts will be the total gross receipts less the cost of development and production. 5. That the present value of the net receipts must be such an amount that when invested by a purchaser it will be returned with 8 per cent, interest additional during the life of the property. The initial procedure consisted in making a general reconnaissance of the entire district in which the property was located and determining the lithological and structural conditions underlying the area. The data obtained from each individual tract comprised the logs of all the wells

Jan 1, 1918

By W. A. Tiller

SEVERAL authors1-6 have shown that, during solidification from the melt, the direction of formation of substructure boundaries depends upon the direction of heat flow and the rate of solidification of the metal. The most prominent of these observations was that a preferred orientation developed during the solidification of the columnar zone of an ingot which for face-centered-cubic metals was the <100> direction. Previous explanations1-&apos; given to account for this preferred orientation and the other boundary phenomena are all based on the premise that the phenomena are characteristics of the pure element. However, recent experiments by Rosenberg and Tiller7 have demonstrated that the preferred orientation in pure lead is the <111> orientation, and that the heretofore observed <100> orientation is due to the effect of solute on the mode of solidification of the metal. Teghtsoonian and Chalmers,4 studying striation boundaries in tin, and Chalmers and Rutter,5 studying corrugation boundaries in tin, showed that these substructure boundaries were aligned parallel to the axis of heat flow for slow rates of growth, and that the alignment varied from this direction as a function of the rate of growth. to approach the den-drite direction at high rates. Chalmers,6 studying the direction of formation of a grain boundary separating two crystals of different orientation, showed that at slow growth rates the boundary is parallel to the axis of heat flow, while at higher speeds it will deviate from this direction, sloping into the crystal whose dendrite orientation departs the most from the axis of heat flow. It is this phenomenon that allows certain crystallites in the chill zone region of an ingot to encroach on their neighbors and ultimately produce the preferred orientation of the columnar zone of the ingot. Since the previous explanations of this preferred orientation are unable to account for the recent observations,&apos; a new mechanism will be considered. This will lead to an explanation of the other substructure boundary phenomena as well. Investigations by Graf,8 Billig,9 Rsenberg,10 and others have demonstrated in a striking fashion that crystal growth takes place by the deposition of individual layers oriented along the close-packed planes of the material considered. This lamellar or

Jan 1, 1958

By Gary P. Thomason

INTRODUCTION One may have heard about how various projects were financed or certain companies were successful in obtaining a bank loan, but there are many more projects and companies who fail to get the money they need. At least a portion of these failures, and a large percentage of the frustrations connected with even the successful financings, are a result of not understanding the process of obtaining money. Recent years have seen a proliferation of debt financing sources available to finance minerals operations (see the next Chapter 11), but these represent only a minor portion of the minerals financing market. The fundamental source of borrowed money to many minerals related companies remains the banks. Therefore, understanding the "Loan Approval Process" can easily mean the difference between getting the money or not. LOAN APPROVAL PROCESS The initial stages of the loan approval process should begin long before the bankers, and the organizations they represent, enter upon the scene. The loan approval can be broken down into six stages: 1) Generation 2) Preparation 3) Presentation 4) Evaluation 5) Approval 6) Documentation As you can see in Figure 1, the bank is only directly involved in the second half of the process. The perils in obtaining financing for the smaller minerals venture are primarily in the first three stages, not the last three. The minerals venture making application for a loan can, in almost every case, improve its chances of success by carefully planning and preparing itself and the information that will be required of it in the loan approval process. Generation This first step in the process is deciding on the need for a loan. (Earlier papers in this Book and in Chapter 11 provide some guidance.) It is surprising how many ventures confuse the need for money with the need for a loan. Suffice to say that the equity investor risks both the timing of the yield on his capital and, ultimately, his capital. The lender, on the other hand, advances temporary funds which he expects to be repaid on a specific schedule with a fixed

Jan 1, 1985

By E. I. Larsen, E. F. Swazy, F. R. Hensel

Experience has indicated that hard bronzes are not suitable for bearing applications where high bearing loads and speeds are involved. It is the general practice to utilize softer materials for these purposes, such as copper, lead, silver, babbitt, lead-base alloys, and more recently aluminum-base alloys, preferably supported by a steel backing. It was the objective of the present investigation to study a new material produced by powder metallurgical methods susceptible to precipitation-hardening. Test MAteriaIs Preliminary tests were made with compacts containing copper, nickel and silicon in quantities sufficient to form 3 to 5 per cent nickel silicide. It mas found that this type of alloy was susceptible to the formation of a soft surface shell when sintered in tank hydrogen. The depth of the shell depended On the length of sintering time and sintering temperature, and varied in thickness from a few thousandths to as much as One eighth inch. This soft shell resulted from the preferential oxidation of silicon, thereby reducing the efficiency of age-hardening by the nickel silicide compound. The body of the sintered compacts below the soft shell could be precipitation-hardened to a hardness of 70 to 85 Rockwell B, by quenching from goo°C. and age-hardening at 450°C. A series of tests was made with various addition agents, in order to decrease the rate of preferential oxidation, and it was found that phosphorus was most beneficial in this respect. After considerable experimentation, the following nominal com-position was accepted as standard: 2.4 per cent nickel; 0.8 silicon; 0.3 phosphorus; balance copper. The physical propertties and certain bearing properties of this alloy are described in the present paper Preparation of Compacts Several methods of incorporating the hardening ingredient (nickel silicide) were studied. Compacts formed from copper, nickel and silicon powders were found to be inferior to those fabricated from prealloyed nickel silicide master alloys, because of the rapid oxidation of pure silicon during sintering. The use of a prealloyed nickel silicide hardener containing 25 per cent silicon and 75 per cent nickel could be further improved by preparing a master alloy, incorporating nickel, silicon, phosphorus and copper, having the following nominal composition~ 25 per cent nickel; 7 silicon; 3 phosphorus 64 copper. This alloy is brittle in the cast condition and can be readily powdered. Sintering Procedure The blended powders were pressed at &apos;5 to 40 tons per sq&apos; in., the pressure depending on the size and shape of the compacts. Sintering was carried out in hydrogen or cracked ammonia atmospheres at

Jan 1, 1946

By E. I. Larsen, E. F. Swazy, F. R. Hensel

Experience has indicated that hard bronzes are not suitable for bearing applications where high bearing loads and speeds are involved. It is the general practice to utilize softer materials for these purposes, such as copper, lead, silver, babbitt, lead-base alloys, and more recently aluminum-base alloys, preferably supported by a steel backing. It was the objective of the present investigation to study a new material produced by powder metallurgical methods susceptible to precipitation-hardening. Test MAteriaIs Preliminary tests were made with compacts containing copper, nickel and silicon in quantities sufficient to form 3 to 5 per cent nickel silicide. It mas found that this type of alloy was susceptible to the formation of a soft surface shell when sintered in tank hydrogen. The depth of the shell depended On the length of sintering time and sintering temperature, and varied in thickness from a few thousandths to as much as One eighth inch. This soft shell resulted from the preferential oxidation of silicon, thereby reducing the efficiency of age-hardening by the nickel silicide compound. The body of the sintered compacts below the soft shell could be precipitation-hardened to a hardness of 70 to 85 Rockwell B, by quenching from goo°C. and age-hardening at 450°C. A series of tests was made with various addition agents, in order to decrease the rate of preferential oxidation, and it was found that phosphorus was most beneficial in this respect. After considerable experimentation, the following nominal com-position was accepted as standard: 2.4 per cent nickel; 0.8 silicon; 0.3 phosphorus; balance copper. The physical propertties and certain bearing properties of this alloy are described in the present paper Preparation of Compacts Several methods of incorporating the hardening ingredient (nickel silicide) were studied. Compacts formed from copper, nickel and silicon powders were found to be inferior to those fabricated from prealloyed nickel silicide master alloys, because of the rapid oxidation of pure silicon during sintering. The use of a prealloyed nickel silicide hardener containing 25 per cent silicon and 75 per cent nickel could be further improved by preparing a master alloy, incorporating nickel, silicon, phosphorus and copper, having the following nominal composition~ 25 per cent nickel; 7 silicon; 3 phosphorus 64 copper. This alloy is brittle in the cast condition and can be readily powdered. Sintering Procedure The blended powders were pressed at &apos;5 to 40 tons per sq&apos; in., the pressure depending on the size and shape of the compacts. Sintering was carried out in hydrogen or cracked ammonia atmospheres at

Jan 1, 1946

By P. W. Bakarian, John C. McDonald

Three magnesium alloys were processed in various ways to exhibit a wide variation in the ratios of yield strength and tensile strength in the rolling direction compared to the cross-rolling direction. Basal-plane pole figures were prepared from several specimens. A fair correlation was observed between the property ratios and the ratio of percent of poles oriented in the cross-direction quadrants compared to the percent oriented in the rolling-direction quadrants of the pole figures. THE modes by which magnesium crystals deform are such as to lead to marked preferred orientations in all forms of wrought products. The effect of the active modes at room temperature, coupled with these orientations, is often to produce a lower compressive yield stress compared to the tensile yield stress. The phenomenon is due to easy twinning in compression, and has been well-related to the preferred orientations as described by basal-plane pole figures of the hcp magnesium single crystal. The literature contains some information on the variation with test direction of the tensile properties of sheet, but no quantitative relationship to the observed pole figures has been established. These effects have been reviewed in the few com- prehensive treatises in English which have been written on magnesium technology and metallurgy.1°3 Roberts presents several pole figures, but no tensile-property data in the plane of the sheet. Raynor has no pole figures, but quotes Frommer&apos;s4 results. The information in Beck&apos;s compendium more or less parallels the results of Jones and powell.5 In both a Mg + 1.5 Mn alloy and a Mg + 4.6 A1 alloy, cold rolling was found not to change the general situation of higher properties in the cross-rolling direction,* than in the rolling direction. Thomas&apos;6 X-ray studies of Jones and Powell&apos;s specimens did not permit correlation of properties and preferred orientation. Ansel and Betterton7 report tensile and compressive properties on three other alloys as a function of degree of cold rolling, plus a recrystallizing anneal. As rolled, there was a change in anisotropy with degree of reduction, but all alloys were reasonably isotropic in tension when annealed. X-ray diffraction photograms illustrated the kinds of orientations present, but were not correlated with the properties. Bakarian8 has described a method of determining quantitatively a preferred orientation, and illustrated the method by applying it to pure magnesium and two of its alloys. This method was used in the present work as a basis for correlating the strength properties with the texture.

Jan 1, 1965

By R. J. Wasilewski

Elastic constants have been determined on single crystals of maximum-melting-temperature NiAl compound (50.6 at. pct Al) at 25°C. Temperature variations of Young&apos;s modulus in the three principal crystal directions between -150°C and +800°C exhibit no anomalies similar to those repovted for the isomor-phous compounds brass and AuCd. It is concluded that the ordered CsCl structure is stable throughout the temperuture range investigated NICKEL aluminide is a congruently melting inter-metallic compound of CsCl (B2) structure, stable over a rather wide composition range (40 to 54 pct Al). It exhibits a lattice-parameter maximum of a. = 2.883A at 50.6 pct 1,&apos; at which composition the excess aluminum atoms are randomly distributed on the vacant nickel sites;&apos; at higher nickel compositions the excess nickel atoms replace substitutionally in aluminum sites, while at higher aluminum compositions vacancies are present in the nickel sublattice.&apos; For compositions close to NiAl no significant variation in order has been observed at temperatures up to 900°C.3 At high nickel (65 pct) compositions the existence of a martensitic structural transformation has been reported.4 NiAl is isomorphous with the ordered B-brass structure and with the high-temperature structures of AuCd and TiNi alloys close to equiatomic composition. All of these exhibit anomalous elastic behavior as the temperature of their diffusionless transformation to lower-symmetry structures is approached.&apos;-&apos; This behavior has been explained as indicative of low stability of the CsCl structure in these compounds.8 The present paper reports the experimental determination of the elastic compliances of single-crystal NiA1. EXPERIMENTAL METHOD 1) Specimens. Polycrystalline NiAl was prepared by induction melting of carbonyl nickel and high-purity aluminum and casting into solid copper molds in gettered helium atmosphere. The castings thus produced were canned in mild steel and impact-extruded at 1100 to 1200°C to 38-in.diam rod. After the steel sheath was pickled off, the rods were converted to single crystals by repeated high-frequency satisfactorily produced the desired orientations in the form of crystals 38 in. diam by 8-12 in. long. These were subsequently center less-ground to 7 to 8 mm diam by 12 cm long, electropolished (in 80 pct methanol, 20 pct HzSO, at 25°C and 15 v), and their axial orientation determined to 1 deg by the Laue back-reflection technique. The rod dimensions were determined to 0.01 mm and the densities determined from geometrical dimensions and the weight of every specimen. The average density was 5.905 0.005 g per cu cm. 2) Elastic Data Measurements. Room-temperature elastic compliances Sii were obtained by determining to 0.1 cps the fundameGtal resonance frequencies in the longitudinal and torsional vibration modes. At these frequencies the following relations hold: E =p(2lfif =pvl= Sn- 2r[Sll- S12- -£„«] g -P(2iftf = pvf = (s<« - fr(sii - sw - ±s»y where vl and vt are the velocities, and f andft the resonance frequencies of the longitudinal and torsional waves, respectively; 1 is the length of the specimen, and r is the direction cosine factor—{cos2 a • cos2 0 + cos2 a . cos2 y + cos2 0 ¦ cos2 Y}. Given three crystals of orientations (loo), (110), and (111)) i.e., F = 0, 14, and 13, we can obtain six equations for the three unknown compliances, thus providing adequate internal check. Mode mixing can readily occur in the relatively long wavelength resonance utilized here. This could cause a significant error in the torsion wave velocities calculated from the apparent resonance frequenies. Therefore, throughout the present work, a method, described previosl,&apos; was used to ensure that no significant mode mixing took place at resonance. The apparatus used was originally designed for the Elastomat, Magnaflux Corp.. Chicago, 111. determination of flexural vibration resonance frequencies. At room temperature torsional vibration mode could be established by suitable positioning of the thin wires from the input and pick-up transducers, and longitudinal mode by cementing thin magnetic foils at the ends of the specimen, and inducing the vibration by means of electromagnetic transducers. Only flex-ural resonance frequencies could, however, be obtained reproducibly over the temperature range of -150 to 800°C. These data are considerably less accurate, the error in the modulus being estimated at -0.6 pct from the specimen dimensions and the room-temperature Poisson&apos;s ratio. The reproducibility of the resonance frequencies in repeat runs was, however, to better than l in 15,000, hence the relative elastic modulus error less than 0.02 pct. Therefore, the temperature variation of the principal Young&apos;s moduli obtained by flexural resonance, relative to room-temperature values, is believed to be satisfactorily accurate.

Jan 1, 1967

By Herbert K. Kutter

This paper is concerned with the physical phenomena in the fracture process of presplitting and only indirectly with the establishment of the optimum presplitting parameters. Its nature is therefore qualitative, rather than quantitative.

Jan 1, 1968

By B. E. Grant

THE major metal mine operations of the United States Smelting Refining and Mining Company in Utah are in the Bingham area. The Company also owns and operates metal mines in the Ophir district, twelve miles south of Bingham, and in the Tintic district, 28 miles south of Ophir. Operations of the Company in the Park City area have been idle since early in World War II. These mining camps, lying at moderate elevations, serviced by railroads, hard-surfaced highways, in close proximity to mills, smelters, cities and towns, fertile valleys, winter and summer vacation areas, and airports are probably as favorably situated as any mining camps in the world. The Bingham district, known principally for its copper production from

Jan 1, 1948

By S. Frederick Ravitz

IN most applied sciences there are two distinct methods of carrying out research and development work. One of these, the theoretical, attempts to solve problems that may arise and to predict facts of practical importance by the application of the various laws of science, the other, the experimental method, attempts to each the &apos;same goal by obtaining data and trying out various processes in the laboratory. Since individuals frequently find themselves better adapted for one or the other type of procedure, it is natural that -two groups should &apos;arise, both working toward the sane objective but with somewhat different points of view, although many in each group are thoroughly competent in both fields. Metallurgy, in particular, offers an excellent opportunity for a comparison of the two methods.

Jan 1, 1935

By J. Jay Jacobsen

A dynamic regional coal development model is constructed for the Eastern Powder River Basin of Wyoming. Using this model, alternative development schedules from a recent environmental impact statement submitted to the Department of the Interior are simulated (Ref. 1). These alternatives include different mixes of export capacity, different coal conversion techniques within the region, as well as various levels of coal production. Exportation of 70 to 80 percent of an ultimate coal production of 180 million tons (163.3 x l09 kg) per year and the careful phasing of additional public services with population growth effectively reduce the social and environmental impacts of coal development. The alternative involving the addition of 43,000 megawatts of electrical generation capacity has very significant adverse social and environmental impacts on the region.

Jan 1, 1977

By Andres M. Liebenthal, Jan M. Mutmansky

This paper is concerned with the layout of a conveyor and beneficiation plant system involving several mines and a single point of delivery. The objective of the procedure is to locate the conveyor lines and beneficiation plants in an optimal manner considering the economics of scale inherent in both the transportation and beneficiation processes. Upon completion of the mining plan, the layout of the conveyor network is achieved through the principle of Steiner minimal trees. The optimal number and location of beneficiation plants for this layout are then determined using a sequential economic analysis based upon the flow of material from the individual sources to the ultimate destination. The practical aspects of the method and the advantages and disadvantages of its use are discussed to link the model to a practical problem.

Jan 1, 1976

By AIME AIME

THE fall meeting at El Paso this year (Oct. 13¬15) will be of unusual interest due to the international atmosphere imparted by the many engineers from Mexico, who are making arrangements to attend this meeting. The meeting will be held jointly with the Western Division of the American Mining Congress. Cooperating in the program will be the representative society of Mexican engineers known as Centro National de Ingenieros of Mexico City, who are plan¬ning on sending many delegates and well known Mexican engineers to the convention. The cooperation of the West Texas Geological Society and the American Association of Petroleum Geologists has also been secured. Brent N. Rickard, manager of the El Paso Smelting Works of the American Smelting & Refining Co. at El Paso, Tex., is general chairman in charge of arrangements. He is receiving splendid cooperation from the Mining Department of the El Paso Chamber of Commerce and from the business people of El Paso, who feel highly honored in having these mining societies meet with them this year.

Jan 1, 1930

By F. Windolph

There are no hard and fast rules for building tailing dams, and each case has to be analyzed individually because of special conditions encountered at each location. Certain criteria are used for building dams at Climax, Colo., where they must be placed in rather steep mountain valleys on foundations that are practically impermeable. The tailing is relatively coarse, and a coarse fraction stays near the berm where it is deposited, while most of the fines flow with the water to the pool. Thirty years experience has led to certain design for toe dams, decanter lines and towers and tailing dams. A new tailing disposal area, started at Climax in 1958, will ultimately have a height of 495 ft and impound about 300 million tons. The following applies to the construction of this new tailing area.

Jan 11, 1961