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By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By R. D. Mollison, C. F. Fogarty

Sulfur is widely distributed in nature. It is present in the earth's crust, the ocean, the meteorites that come to us from cosmic space and in practically all animal and plant life. According to Clarke,9 the earth's crust contains 0.06 pct sulfur. Large quantities of free or combined sulfur are found in coal, natural gas and petroleum. Mineral waters contain sulfates and hydrogen sulfide. Sulfur is rather plentiful in the crust of the earth; however, only under special circumstances can it be produced profitably. Sulfur is one of the cheapest raw materials used by industry; and, therefore, the economic feasibility of a given deposit is strongly dictated by the law of supply and demand on local as well as world-wide levels. The forms which are commercially important are elemental sulfur or brimstone, and the sulfides such as pyrite (FeS2), pyrrhotite (FenSn+1), chalcocite (Cu2S), sphalerite (ZnS), and galena (PbS); the sulfates such as gypsum (CaSO4,2H2O), anhydrite (CaSO4), and kieserite (MgSO4,H2O). Elemental Sulfur Elemental sulfur is found in many localities, generally in solfataras and gypsum type deposits. The solfatara deposits are found commonly in the neighborhood of active or extinct volcanoes as in Italy, Japan and Chile, or fumaroles associated with mineral springs such as the Mammoth Hot Springs in Yellowstone Park. Here the sulfur is deposited in tufas or other porous host rocks. This type of sulfur deposit probably results from the oxidation of hydrogen sulfide or the reaction of hydrogen sulfide with sulfur dioxide. Most of the world's supply of elemental sulfur comes from the gypsum-type deposits. Here the mineral occurs as either crystalline or amorphous sulfur in sedimentary rocks in close association with gypsum and limestone. This association is characteristic and occurs in almost all the great gypsum beds of the world, although sulfur is not always present in quantities of economic importance. Various theories have been advanced to account for this association. Bischof5 suggested that the sulfur came from hydrogen sulfide which resulted from the reduction of calcium sulfate by carbon or methane in accordance with the following reactions: CaSO4 + 2C= CaS + 2CO2 CaS + C02+ H2O = CaCO3 + H2S CaSO4 + CH4= CaS + C02+ 2H20 2H2S + 02= 2H20 + 2S All of the sulfur-bearing domes on the Gulf Coast have calcium sulfate in great quantity in the cap. They all show the presence of hydrocarbons. The oxygen for the final reaction could have been supplied by circulating ground waters. The principal objection to this theory is that temperatures of 700° to 1000°C are needed to reduce the sulfate to sulfide with carbon compounds. The geologic evidence is that the temperature of the sulfur-bearing domes of Texas did not exceed 100°C. Proponents of the theory say that geologic time or a catalyst replaced temperature. According to another theory the sulfur in the salt domes is the result of bacterial action. Sulfate reducing bacteria have been detected in sulfur cores and in the formation water issuing from salt domes. It has, therefore, been suggested that these bacteria converted the sulfate to sulfide which subsequently was converted to elemental sulfur.

Jan 1, 1960

Executive HENRY A. BUEHLER, Chairman ERLE V. DAVELER EDGAR RICKARD JOHN M. LOVEJOY WILLIAM WRAITH J. V. W. REYNDERS, Consultant Finance HENRY KRUMB, Chairman E. E. ELLIS PAUL D. MERICA H. G. MOULTON, Consultant Admissions RALPH M. ROOSEVELT, Chairman GEORGE D. BARRON DONALD M. LIDDELL WILBER JUDSONW. D. B. MOTTER, JR.

Jan 1, 1934

By P. W. Neurath, R. E. Waite

INFORMATION is available on the effect of stress on permeability, coercive force, and hysteresis for a variety of materials' but for the technically important grain-oriented 3 pct Si-Fe' the stress effects are not adequately covered in the literature; in addition, most of the stress data do not permit estimation of what would happen to the 60 cycle watt losses of the material under stress. Direct measurement of these effects therefore has been made and appears to be of considerable theoretical as well as practical interest. Losses were measured on the central 25 cm portion of 40~3~0.035 cm samples which could be stressed in a small tensile machine built for this purpose. Under tension the following effects, illustrated in the figures by a particular example, were observed: 1—"Unstrained" material of commercially acceptable loss level shows no change or a small increase in loss at low elastic stresses. For the sample shown in the figures, this is illustrated during the initial run, where a 7 pct increase is observed (Fig. 1). 2—There is no additional change in loss when the sample is further strained up to the elastic limit (Fig. 1). Within that limit the loss-stress curve is reversible. This is not illustrated in Fig. 1. 3—Even in the plastic range only small increases in loss are observed as long as the sample is kept under stress (Fig. 2, point N); often no increase can be observed (Fig. 1). 4—A large increase in watt losses is observed after removal of the stress subsequent to plastic deformation (Figs. 1 and 2). 5—All, or nearly all, of the foregoing increase in loss due to plastic deformation can be eliminated by a reapplication of tensile stress but returns upon removal of this stress. This is illustrated in the third run (Fig. 3). This run remains within the elastic limit and shows the reversibility of the stress-loss curve under this condition. These findings have been confirmed on large Samples (approximately 200~10~0.035 cm and larger) except that under 1 no initial increase in loss was ever observed on these. The accuracy of the watt loss measurements is of the order of 1 pct. Neither bending of the sample in the tensioning device nor a redistribution of flux along the width of the sample accounts for these results. They therefore must be explained on the basis of either a change in the domain configuration due to stress or a change in the domain wall mobility. Acknowledgment The assistance of Mr. Robert L. TenBroeck with the instrumentation is gratefully acknowledged.

Jan 1, 1956

By L. C. Uren

Field studies and laboratory research have established the fact that the expulsive force which drives petroleum into wells, from the reservoir sands in which it is stored by nature, is primarly an expression of the energy latent within compressed natural gas dissolved or occluded in, or otherwise associated with the oil. Each barrel of oil produced is forced into the recovery well by the expansive energy of a certain volume of compressed gas, originally stored with the oil in the pores of the reservoir rock; and each cubic foot of gas so produced with the oil and expanded to atmospheric pressure reduces by so much the total natural energy available for oil expulsion. This relationship between the volumes of gas and oil produced has seemed so important that petroleum production technolo-gists have come to regard the "gas-oil ratio," or the "gas factor" as it has been more conveniently termed, as a measure of oil-production efficiency. Different methods of oil recovery and production devices are now Com pared on this basis and estimates of ultimate recovery obtainable through their use are considered by many to be inversely proportional to the values of their respective gas factors. The writer has been among those who have given support to a widcspread movement toward a proper recognition of the significance of the gas factor as a guide in the control of producing oil wells, and does not wish to oppose its more extended application. It seems necessary, how-cvcr, in view of the almost elemental faith with which the principle of the gas factor has been received in many quarters, to point out that it is a most complex factor, and one which cannot be regarded as an absolute index of production efficiency without due regard to other contributing factors by which it is influenced to an important degree. Variables Influencing Gas Factor The mere recording of a low gas factor, obtained through the use of some method or device, does not necessarily imply efficient oil production; and conversely, a high gas factor does not always signify inefficient recov-

Jan 1, 1928

All the TECHNICAL PUBLICATIONS and CONTRIBUTIONS published in 1936 arc available at Institute headquarters, unless otherwise noted They are also on file in many public, university and technical libraries and, when so indicated in the list, may be found in the TRANSACTION Copies of the TECHNICAL PUBLICATIONS have been mailed to members of the Institute that are registered in the different classes A-Metal Mining, B-Milling and Concentration, C-Iron and Steel Division, D-Nonferrous Metallurgy, E-Institute of Metals Division, F-Coal Division, G-Petroleum Division, H-Industrial Minerals Division (Nonmetalhcs) , I-Mining Geology, L-Geophysical Prospecting Other members may obtain copies by writing to the Secretary Copies of CONTRIBUTIONS may also be obtained from the Secretary's office Additional copies are sold at the rate of 1 cent per page, minimum charge, 25 cents Non-members may purchase the papers to the prices mentioned

Jan 1, 1937

Book Review MANAGEMENT AND MEN. By Meyer Bloomfield, Boston. The Century Co., New York, 1919, pp. 584, H.X. 5 1/2. $3.50. This hook is an exposition of English efforts to solve the problem of labor unrest in England. The first six chapters are reprinted from articles published in the Satur-day Evening Post, for whom the author went to England to study the problem at first hand. These articles deal with housing, increased production, eliminating the internal friction in the industrial machine and a chapter each devoted to the view-point of employer and employee. These chapters are written in the easily readable magazine style and give a complete general survey of the particular solution being tried. Perhaps their greatest., certainly not their least, worth lies in the fact that they form a vehicle for unusually voluminous appendices containing in full the famous Whitley Reports which are the basis of the new movement, together with various reports, which, except for this publication, would be largely inaccessible to those inter-ested in this country. The Whitley scheme considers each industry a unit and proposes to establish therein a Joint Standing Industrial Council composed of representatives of employers and employees to consider appropriate matters affecting the industry at large. There is to be a District Council for each industry which will, as its name implies, deal with the clatters pertaining to that interest in. the particular district. The third and last body in this scheme of Industrial Parliament is the Works Committee, which is com-posed of representatives of the management and of the workers employed in particu-lar plants or mines to act in close cooperation With the district quid national machinery. The Whitley or similar schemes have been tried in many communities in England and the book contains interesting comments on the result obtained, it being notable that most of the objections conic from plants which have not tried the scheme. Meyer Bloomfield, the author; is the specialist in industrial personnel problems who organized the industrial service activities of the United States Shipping Board, Emergency Fleet Corporation. P. E. B.

Jan 10, 1919

Fred D. DeVaney (Magnetic Roasting of Iron Ores, P. 1219) has presented several other AIME papers, all of them concerned with grinding and concentrating problems. He is chief metallurgist, Pickands Mather & Co., at Hibbing Minn., after working for the U. S. Bureau of Mines at Tuscaloosa, Ala., and Rolla, Mo., as a junior metallurgist and a metallurgist. DeVaney started as a research metallurgist with Pickands Mather in 1942. He set up the first laboratory in the Lake Superior district devoted to taconite concentra¬ [ ] tion, his major interest. He has been an AIME member since 1923, holding various offices, including the first presidency of the Minnesota Section. DeVaney has a Bachelor's in Mining, and Master of Science earned at the University of Alabama in 1924. He is a member of the Engineers Club of Northern Minnesota and plays golf for relaxation and enjoyment.

Jan 1, 1952

By Frederick Laist

I. EXPERIMENTAL FLOTATION CONCENTRATION INTRODUCTION EARLY in 1914 it was decided to test, on a fairly large scale, the treatment by flotation of Anaconda slime and mill tailing. For this purpose a standard-type Minerals. Separation machine was installed at the Washoe Reduction Works during May and June, 1914. This was followed by the. installation of a full-size Callow pneumatic machine plant. Experiments were also made, on a smaller scale, with the Froment, the Towne, the Fields, and the Anaconda flotation machines. The last-named machine was developed at this plant. In addition to the tests made in the standard-type Minerals Separation machine some tests were made using a Minerals Separation machine of the sub-aeration type. During the series of experiments a large variety of oils was tested. Experiments were also conducted using both round-table feed and tailing to determine whether it would be better to displace the round tables by flotation for the treatment of the slime, or to supplement the round tables by flotation of the round-table tailing. A series of tests was also made on the treatment of the mill tailing by grinding followed by flotation to determine the relative merits of flotation and leaching for the treatment of this product. In addition, flotation tests were made on mixtures of mill tailing and slime. The round-table feed referred to above is the total slime from the mill. It contains about 35 per cent. colloidal solids and approximately 90 to 95 per cent. of the total solids will pass through 200 mesh (0.067 mm.). It assays from 2.3 to 2.6 per cent. Cu. The mill tailing referred to above is the total discard from the mill, exclusive of the slime. It is all finer than 2 mm. and about 90 to 95 per cent. will remain on 0.25 mm. It assays about 0.60 per cent. Cu. A brief summary of the experimental flotation results follows:

Jan 3, 1916

By Samuel B. Christy

Columbia College has the honor of founding the first well-organized School of Mines in America. The University of Michigan, however, shared with her the honor of graduating the first class, in 1867. Prof. Thomas Egleston was the pioneer in the new movement. He drew up the original plan for the Columbia School of Mines in 1863, and was in 1864 appointed its first professor. The Massachusetts Institute of Technology turned out a class of mining students a year later, and others followed in the order of their first graduating class, as shown in Table I., condensed from the Engineering News of August 11, 1892. Besides those mentioned, mining schools have been organized in the States of Arizona and Nevada, and more or less instruction is advertised in connection with other engineering schools. It will be noticed that Columbia easily heads the list with reference to the number of graduates; the Massachusetts Institute of Technology stands second ; the California University third, and then follow Lehigh, Washington University, the University of Michigan, Lafayette College, Michigan Mining School, Missouri, Colorado and the others. The total number of graduates from these 16 schools in 26 years, has been 871, or an average of 33 per year; but as all these schools give a partial education to many who do not graduate, it is probable that from 2000 to 3000 mining students have received from them considerable training. An interesting comparison of the rate of growth of the engineering schools has been recently instituted by the Engineering News, for the period between 1860 and 1892. Table 11. shows that civil engineering had the advantage in numbers from the start, and maintained the advantage until 2890, when it was surpassed by mechanical engineering. The development of the latter course may be said to date from 1880. There are many interesting facts evident in Table 11. It will

Jan 1, 1894

By Albert E. Wiggin, Frederick Laist

Early ill 1914 it was decided to test, on a fairly large scale, the treatment by flotation of Anaconda slime and mill tailing. For this purpose a standard-type Minerals Separation machine was installed at the Washoe Reduction Works during May and June, 1914. This was followed by the installation of a full-size Callow pneumatic machine plant. Experiments were also made, on a smaller scale, with the Froment, the Towne, the Fields, and the Anaconda flotation machines. The last-named machine was developed at this plant. In addition to the tests made in the standard-type Minerals Separation machine some tests were made using a Minerals Separation machine of the sub-aeration type. During the series of experiments a large variety of oils was tested. Experiments were also conducted using both round-table feed and tailing to determine whether it would be better to displace the round tables by flotation for the treatment of the slime, or to supplement the round tables by flotation of the round-table tailing. A series of tests was also made on the treatment of the mill tailing by grinding followed by flotation to determine the relative merits of flotation and leaching for the treatment of this product. In addition, flotation tests were made on mixtures of mill tailing and slime. The round-table feed referred to above is the total slime from the mill. It contains about 35 per cent. colloidal solids and approximately 90 to 95 per cent. of the total solids will pass through 200 mesh (0.067 mm.). It assays from 2.3 to 2.6 per cent. Cu. The mill tailing referred to above is the total discard from the mill, exclusive of the slime. It is all finer than 2 mm. and about 90 to 95 per cent. will remain on 0.25 mm. It assays about 0.60 per cent. Cu. A brief summary of the experimental flotation results follows:

Jan 1, 1917

By P. Bandopadhyay, T. C. Rao

Geologically the Indian coals belong to Gondwana formations. Being of drift origin, these coals contain high percentage of mineral matter distributed in finely disseminated form. Indian coal-preparation plants process prime coking and medium coking coals for use in steel plants. Limited resources of good quality coking coals (Table 1) could not keep pace with the rapid developments of the iron and steel industry in India. This resulted in the introduction of coal-preparation technology and the establishment of washeries in India in the last 30 years or so. The first four washeries were set up during the early fifties at West-Bokaro, Jamadoba, Lodna and Kargali. Next came the first non-coking coal washery at Nowrozabad set up by the Associated Cement Company. In 1961, following the recommendation of Central Coal Washeries Committee (1953-54), Hindustan Steel Ltd. had set up five central washeries at appropriate locations, viz Durgapur, Dugda (2 washeries), Patherdih and Bhojudih, so that the raw coal feed having similar washability characteristics can conveniently come from a number of collieries to a particular washery. Subsequently, to meet the increasing demand of metallurgical coal by steel plants, two more central washeries (at Durgapur and Chasnala) and three pit-head washeries (at Kathara, Swang and Gidi) were installed by 1970. The prime objective of washing Indian coking coal is essentially to reduce the ash content. All the washeries in India, taken together have an installed capacity of about 26 million tons of raw coal input per annum. Details of these washeries in respect of their annual capacity, main washing systems adopted and the nature and size of the products are given in Table 2. It can be observed from this table that (1) bulk of the coal is processed in units like jigs HM baths and HM cyclones; (2) only two of the washeries have cleaning circuits for treatment of fines.

Jan 1, 1980

By Charles M. Rolker

(Read at the Philadelphia Meeting, February, 1878.) THE Mariposa estate, a grant made by the Mexican Government to Juan B. Alvarado, during the time when California was still under the dominion of Mexico, was purchased in 1847 by J. C. Fremont, and the United States patent issued to him in 1856. By sale, or its equivalent, money advanced, the property came into the hands of the Mariposa Company, June 25th, 1863, and through a varied existence of work and temporary inactivity, has as yet been kept as an undivided property, and rests at present with the Mariposa Land and Mining Company of California. I pass over this period of 15 years without giving the history of the ups and downs of the estate, partly because it is familiar to many, and also because I think in such a case this paper would assume too much the character of a narrative. The estate is situated in Mariposa County, California, about 170 miles southeast of San Francisco. It begins in lat. 37° 26’ 38" - north, and long. 119° 55' west, and runs 6 miles north; thence 6 1/2 miles west; thence 5 miles northwesterly towards the Merced River; thence 8 1/2 miles southerly; thence 3 miles easterly; thence 1 mile southerly; thence 2 miles easterly; thence 2 miles southerly; thence 2 miles easterly; thence I mile southerly; thence 2 miles easterly; thence 1 mile northerly, and thence 2 miles easterly to the place of the beginning; embracing 44,387 acres (70 sq. miles) more or less. To describe this vast estate in detail as to its full geology, its numerous quartz veins, its many facilities to exploit them and work them by cheap methods, would lead me further than I intend to go at present, and I will content myself to describe the latest workings of the company and its immediate field of operations. As long ago as 1860 the late Dr. Adelberg advised the running of an adit from the northwestern edge of the estate at Benton Mills on the Merced River. His object was to undercut the deepest workings of the then paying mines on the estate-the Pine Tree and Josephine. Following this advice, the tunnel known as "River Tunnel" was commenced. Its entrance is in S. 5, T. 4, S. R. 17 E. It is run in

Jan 1, 1878

An Engineers' Symposium was held Wednesday evening, Mar. 26, in the auditorium of the Engineering Societies Building, 29 West. 39th St., under the general auspices of the Local Sections of the American Institute of Mining and Metallurgical Engineers, American Society. of Mechanical Engineers, and the Society of Automotive Engineers. It was participated in by members of the American Institute of Electrical Engineers, American Society of Civil Engineers, American Chemical Society, American Electrochemical Society, American Institute of Chemical Engineers, American Society of Heating and Ventilating Engineers, American. Society of Refrigerating Engineers, New York Electrical Society, Brooklyn Engineers' Club, Illuminating Engineering Society, Institute of Radio Engineers, Municipal Engineers of the City of New York, Society de Chemie. Industrielle, Society of Chemical Industry, and the Society of Naval Architects and Marine Engineers. In opening the meeting the chairman, Gano Dunn,* said: The program calls this an engineers' symposium, which means a putting, together of things, and these things tonight are ideas of fundamental relations to the engineering profession and the engineering societies. Not only engineers, but all men nowadays are examining their views in respect to their relation to what we call Society. My conception of Society is that there is no such thing in the concrete sense of the word. It is an abstraction, and just in proportion as it is a generalization and broader in scope than the particulars from which it is drawn, so is it emptier of content. That does not mean that it is not important, but it does mean that we should be careful and not be led astray into a zeal for doing things for Society that we would not do for our fellow engineers and our brothers. The man who is unwilling to do something for his brother or fellow engineer and yet urges that same thing for Society-is thoroughly inconsistent and, in my opinion, wrong.

Jan 5, 1919

Jan 1, 1882

By M. W. Von Bernewitz

AN important regional meeting of the American Institute of Mining and Metallurgical Engineers was held, at Salt Lake City on Aug. 22 to 26, jointly with the fifth annual meeting of the Western Division of the American Mining Congress. The whole meeting was marked by enthusiasm, keen attention to the subjects under discussion, and many renewals of personal contacts. The trips to the various plants were well attended and the local press paid much attention to the meeting. The A. I. M. E. sessions began Aug. 23, with a non-technical morning session. J. 0. Elton, manager for the International Smelting Co., presided. The purpose of this session was to present in a non-technical manner the relation of flotation to mining, smelting, and the State. Ernest Gayford, metallurgist with the General En-gineering Co. of Salt Lake City, gave the definitions of flotation as suggested by Rickard, the dictionary, Weinig, and Taggart. The active agent in flotation is the air bubble, and the two prime requisites are the formation of bubbles and the creation of selective action of the bubbles for metallic particles instead of for gangue particles. Broadly, all the sulfides are floatable minerals, but the oxides, carbonates, silicates and sulfates are not. As far as Utah is concerned, flotation has been one of the greatest means of conserving its natural re-sources, because it has converted millions of tons of waste rock into pay ore; it is recovering millions of pounds of metal formerly lost in tailings; it has con-verted the zinc from a liability into an asset; and has kept thousands of men at work and distributed millions in dividends for the benefit of the State. As to the future of flotation, Mr. Gayford can con-ceive that the next 5 or 10 years may see as much, if not more, advance than was made in the preceding period. The big problem is dressing oxides, carbonates, silicates, and sulfates, and simplification of the number of reagents, also the separation of different gangue min-erals from one another.

Jan 10, 1927

Edward Keller, Baltimore, Md. (communication to the Secretary): When, at the New Pork meeting, February, 1899, Mr. Douglas gave an abstract of his highly interesting paper on the Copper Queen mine, he invited the members of the Institute, in his usual progressive spirit, to make a full scientific investigation of the region of that mine during the prospective excursion to Bisbee, Arizona. I volunteered to examine some of the metallurgical processes and products of the works, and obtained from Mr. Douglas a valuable series of samples. Upon the issue of his paper, however, I found that he had already a considerable volume of analyses of those products, and that little was left for me to do in that respect, except to duplicate his results, the importance of which work would not have been commensurate to the time and labor involved. I selected, therefore, only some points which he had not made entirely clear, or concerning which I was skeptical. The details of most of my work will appear in a future paper. From Mr. Douglas's figures I have calculated the values for the elimination of impurities in the so-called Leghorn converter, introduced by him at the Copper Queen works, and have found them to be as follows: Percentage of Elimination of Impurities in Pour Blows of a Converter. No of ' Selenium Sulph'r Iron. Zinc. I Nickel. Lead. Antimony Arsenic. and Blow- ! Tellurium .. 1.......... 99.4 99.6 88.0 92.6 94.4 81.6 83.8 40.3 2.......... 99.0 99.6 98.1 92.5 96.8 71.9 76.6 38.1 3.......... 98.8 99.5 93.5 91.4 96.3 63.8 80.6 25.3 4.......... 99.8 99.5 95.8 95.8 97.5 65.3 76.9 36.3 Average 99.2 99.6 93.8 93.1 . 96.2 70.6 ! 79.5 35.0

Jan 1, 1900

By W. F. Hosford, E. W. Kelley

Deformation studies have been conducted at room temperature on single crystals of magnesium and magnesium alloys with thorium and with lithium. Single crystals oriented to suppress shear on the easily activated basal slip systems were deformed by plane-strain compression. Compression along the C axis was accommodated by {1011} banding. Compression perpendicular to the unconstrained c axis activated {1012} twinning, and, after virtually complete twinning, deformation continued by {1011) banding in the twinned material. Compression perpendicular to the constrained c axis was accommodated by the simultaneous operation of (1012) twinning against the constraint and (1011 ) banding. Although this orientation was favorable for {1010)(1210) prism and {1011}(1~10) pyramidal slip, these modes were not observed in pure magnesium or in Mg-0.5 pct Th. However, {10i0)(1~10) prism slip was observed in crystals of Mg-4 pct Li during compression perpendicular to the constrained c axis. Fracture in all materials occurred parallel to (1124) or {l~il) depending on the orientation and composition of the specimen. THE mechanical behavior of the hcp metals is strongly anisotropic. Although several slip systems have been reported the slip is cpmmonly in the directions of closest packing, the (1210),' and this does not produce strains parallel to the c axis. Hence the inherent anisotropy. The deformation mode most easily activated in magnesium at room temperature is (0001)(1210)- basal slip. Also {1010}(1~10) prism slip and {1011)(1210) pyramidal slip have been reported, primarily at elevated temperatures.2"4 However, at room temperature the shear stresses to activate the prism and pyramidal modes are roughly a hundredfold greater than that required for basal slip.'j4 Thus prism and pyramidal slip may be expected only under special conditions of loading. Strains normal to the basal plane can be produced by twinning, however. Many twinning modes have been reported for magnesium,' with (1012) twinning the most common and relatively easy to activate. Magnesium can deform by (1012) twinning when stressed along the c axis jn tension, but not in compression. In contrast, (1011) twinning is activated by compression along the c axis and not by tension. In addition to primary twinning, secondary twinning or slip can occur within the reoriented material of primary twins.' In general at least five independent shear systems must be active to bring about an arbitrary shape change such as that in the individual grains of a deforming polycrystalline material.' Because basal slip can_ provide only two independent shear systems and (1012) twinning can only accommodate an extension of the c axis, other deformation modes must be active in magnesium for an arbitrary shape change to occur. The purpose of this investigation has therefore been to study the various deformation modes in magnesium at room temperature, with special emphasis on those modes that are less easily activated. The effect of the alloying elements, thorium and lithium, has also been investigated. In polycrystalline aggregates, unambiguous identification of deformation modes is extremely difficult and the direct evaluation of the resolved shear stresses to activate them is not feasible. On the other hand, uni-axial tension and compression experiments on single crystals may not activate some of the- deformation modes because basal slip and/or {1012) twinning cannot be suppressed in most orientations. However, it should be possible to activate all possible deformation modes using oriented single crystals and plane-strain compression. Identification of active deformation systems and evaluation of the resolved shear stresses required to activate them should be facilitated. Wonsiewicz and Backofen have recently completed an investigation of the plasticity of pure magnesium crystals at various temperatures utilizing plane-strain compression and selected crystal orientations. This technique has also been used in the present work. The seven orientations selected for study are indicated in Table I. Plane-strain compression along the c axis (orientations A and B) should activate some deformation mode _other than basal, prism, or pyramidal slip, or (1012) twinning. In orientations C and D, prism or pyramidal slip would be expected to take place. When the compressive load is applied perpendicular to an unconstrained c axis (orientations E and F) the three slip modes should be suppressed but not (10i2) twinning. In orientation G, basal slip should occur.

Jan 1, 1969

By Michael B. Bever, John R. Anderson

Carbon may affect the alloys of copper in several ways. Provided an alloying element does not oxidize preferentially, even minute quantities of carbon dissolved in liquid alloys of high copper content will form insoluble carbon oxide gases under oxidizing conditions. Gas porosity in castings of high-copper alloys can originate in this way. In certain alloys of low copper content carbon may have considerable solubility and may be an effective deoxidizer. In these alloys carbon will tend to suppress porosity. Carbon that is dissolved in the molten alloy is likely to be retained in the solidified metal. The effects of carbon on the physical properties of the metal are determined by the form in which it is present. Depending on the alloying elements and also on the cooling rate, carbon may precipitate as graphite, may form a carbide or may remain in solid solution on cooling. As solid copper does not dissolve a measurable amount of carbon, a carbon-bearing solid solution can occur only if the copper is alloyed with a large excess of an element that forms such a solution. The effect of graphite or of carbides on the properties of an alloy will depend on the size and distribution of the precipitated particles. As Hensel pointed out in discussion,' the formation of an alloy carbide may interfere with the age-hardening properties of a copper alloy. One would also expect that the presence of carbides or of graphite will under certain conditions promote corrosion or high-temperature failure in nonferrous alloys. Since carbon has an effect on the soundness of castings and affects the structure and behavior of solid copper alloys, its solubility in the liquid alloys is of practical importance. The isothermal change of carbon solubility with alloy composition is of interest from a theoretical standpoint. The binary alloys of copper with manganese and with nickel are used industrially and serve as a base for more complex alloys. The solubility of carbon in each of these metals is known, but its solubility in their alloys has not been determined. Earlier Data The solubility of carbon in molten pure copper is about o.oooi pct at II00°C and 0.0004 pct at 1475°C.l Various authors2""6 have published data on the solubility of carbon in molten manganese. There is agreement on a value of about 6.7 pct in the temperature range r2170 to 1245°c This solubility value corresponds to the formula Mn3C. It increases very little with increasing temperature. Corson7 states that carbon is soluble in copper-manganese alloys and that the

Jan 1, 1947