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By Ingersoll Olmsted

These ores are of two classes, Bessemer and non-Bessemer, existing in separate, though adjoining, beds. Both are carbonates, with small admixtures of oxides and other combinations. To prepare them for market they are roasted in kilns, which have already been described by Mr. John Birkinbine at the Troy Meeting, October, 1883 (Trans., xii., 378). Concerning their size, arrangement, etc., I need, therefore, only repeat that they are 60 feet in height; have wrought-iron shells 24 feet in diameter; are lined with fire-brick, and supported by cast-iron mantel and columns.

Jan 1, 1889

By T. Sterry Hunt

Jan 1, 1891

By A. S. McCreath

Jan 1, 1884

By Robert H. Richards

Jan 1, 1897

September 1 to 6, 1918 COMMITTEE IN CHARGE Spencer Penrose, Chairman. George M. Taylor, Vice-Chairman. A. E. Carlton, Chairman. Finance Committee J. Dawson Hawkins, Secretary DENVER COLORADO SPRINGS CRIPPLE CREEK Finance Finance Thomas B. Crowe T. B. Stearns A. E. Canton , E. P. Arthur, Jr. Richard A. Parker Spencer Penrose N. S. Greensfelder T. B. Burbridge George M. Taylor A. E. Carlton. A. L. Blomfield, Treasurer B. F. Hill Arrangement I F. G. Willis Dave G. Miller Registration Norris E. Eads Frank Bulkley Loren C. Lennox 1V. E. Ryan Geo. E. Collins Horace F. Lunt Fred Jones .1. M. Tippett F. D. Smale Entertainment J. H. Haynes F. H. Bostwick Arrangement and Entertainment L. W. Lennox F. E. Shepard George M. Taylor A. L. Blomfield M. R.. Valentine Howland Bancroft J. D. Hawkins Thomas B. Crowe B. P. Morse A. E. Carlton E. P. Arthur J. G. Perry G. H. Clevenger Etienne A. Ritter Ladies Ladies , PUEBLO Mrs. T. B. Stearns, Mrs. C. M. Taylor, Mrs. C. H. Clevenger J. F. Welborn Chairman. Chairman H. B. Carpenter Mrs. C. Loughridge Mrs. S.-Penrose Mrs. A. E. Carlton L. B. Eames Mrs. H. Bancroft Mrs. J. D. Hawkins Mrs. A. L. Blomfield F. Robinson Mrs. G. Bancroft Mrs. L. C. Lennox Mrs. J. M. Tippett . Mrs. W. D. Leonard Mrs. H. F. Lunt -Mrs. E. C. van Diest Mrs. C. Chase Mrs. E. A. Ritter Mrs. AV. Strieby Mrs. F. H. Bostwick Mrs. L. S. Harner Mrs. C. L. Bailey Mrs. F. Bulkley Miss F. Dickerman Mrs. E. P. Shove Mrs. C. L. Tutt Mrs. F. C. Peck Mrs. F. D. Pastorius

Jan 10, 1918

By Jerry L. Straalsund, D. Bruce Masson

A dew-point technique was used to determine the thermodynamic activity of zinc at 430°C in a series of e phase Ag-Zn alloys. The composition of the alloys ranged from 72 to 88 at. pct Zn. This range included the composition at which Massalski and King3 found a reversal in the composition variation of the crystallo-graphic c/a ratio, which they attributed to an overlap of the Fermi surface across the (002) faces of the Brillouin zone. The data is presented in a graph in which RT In yz,, where yz, is the activity coefficient of zinc, is shown as a function of atomic percent zinc. This curve has an unmistakable change in slope at the same composition that Massalski and King observed the beginning of the reversal in the c/a ratio. This change in slope of the thermodynamic data is also attributed to a Brillouin zone overlap. Equations are presented to demonstrate that the thermodynamic activity can be related to the density of states of the conduction electrons, and that the observed phenomena are consistent with this model. It is also demonstrated that the contribution of the density of states can be related to the excess stability, a phenomenological parameter recently shown by Darkeen" to be significant in the interpretation of thermodynamic data of metallic phases. The data seem to indicate that zone overlap has caused a spinodal point, and the resulting misci-bility gap, in the phase diagram. THE problem of developing an adequate thermodynamic model of solid solutions has proven to be difficult, and is still only partially solved. The main approach has been to develop a statistical model, such as that of an ideal solution, regular solution, and so forth, to which can be attached corrections for electronic, vibrational, magnetic, ordering, or other contributions. Such corrective terms are usually derived on an ad hoc basis, and it is difficult to predict in advance what their relative importance will be. This problem has been discussed in general terms by Oriani and Alcock,' who have reviewed several thermodynamic models and a few empirical correlations. The measurements described in the present paper were made to demonstrate in a special case the importance of one such corrective term, the contribu- tion of the energy of the conduction electrons of an alloy. It was our premise that the contribution of the energy of the conduction electrons to the thermodynamic activity of the alloy components could be detected; further, that such an effect would be observed at alloy compositions where other phenomena, also ascribed to the energy and density of states of the conduction electrons, are observed. The idea of the importance of the conduction electrons is hardly new. Hume-Rothery and his adherents have developed the well-known theory of alloy phases in which the sequence of phase fields in binary equilibrium diagrams, especially those involving the noble metals with the IIB, IIIB, and IVB subgroups, can be correlated by replacing the composition variable with the ratio of conduction electrons to atoms, e/a. Jones and others have developed a physical explanation for this correlation, in which they consider the solubility limits of phase fields to be restricted by an intersection between the Fermi surface and a Brillouin zone. The general features of the model are also quite well-known—presumably zone intersection causes the density of states to decrease at critical alloy compositions. The attendant increase in energy of conduction electrons in the original crystal structure allows an alternate structure to become more stable as the concentration of polyvalent solute is increased. In spite of the wide acceptance of these ideas on phase stability, there is only indirect* evidence, such as the variations in lattice parameter recorded extensively by Massalskizy3 and others, that Brillouin zone interactions occur. There are few experimental measurements, other than the correlations of the phase sequence, that substantiate the premise that the energy of conduction electrons affects the solubility limits of alloy phases. Much thermodynamic data of alloys has been found to be consistent with the theory; yet there is a lack of detailed data at compositions where zone intersection and overlap are thought to occur. One would expect that the energy of the conduction electrons would make a measurable contribution to the thermodynamic properties of alloys at compositions near zone intersection and overlap if the theory of Hume-Rothery and Jones is correct. This conclusion cannot be avoided, because the phase boundaries are determined by the requirement that the chemical potential of the components be equal in both phases at equilibrium. An electronic effect large enough to alter the stability of a phase should also affect the thermodynamic activity by a measurable amount.

Jan 1, 1969

By George S. Ansell, Thomas E. Davidson

It has been known for a considerable period of time that the ductility of even quite brittle materials can be enhanced if they are deformed under a superposed hydrostatic pressure of sufficient magnitude. The response of ductility to pressure, however, has been shown to vary considerably between materials. Prior work has shown that the effects of pressure upon the tensile ductility of Fe-C materials depend upon the amount, shape and distribution of the brittle cementite phase. In this current investigation, the effects of pressure upon the fracture mechanisms in a series of annealed and spheroidized Fe-C materials were examined. It was observed that the principal effect of pressure is to suppress void growth and coalescence, retard cleavage fracture and to enhance the ductility of cementite platelets in pearlite. Based upon the observed effects of pressure upon the fracture mechanisms, a proposed explanation for the enhancement in ductility by pressure and for the structure sensitivity of the phenomena is presented and discussed. THE effect of superposed pressure upon the tensile ductility of a variety of metals has been well documented.'-'' Some of the results from several investigators are summarized in Fig. 1 where tensile ductility in terms of true strain to fracture (ef) is plotted as a function of the superposed pressure. As can be seen, a pressure of sufficient magnitude can significantly enhance the ductility of metals. However, Fig. 1 also demonstrates that the response of ductility to pressure and the form of the ductility-pressure relationship varies considerably between materials. Several explanations have been offered for the observed enhancement in ductility by a superposed pressure. Although no experimental evidence was provided, Bridgman13 and Bobrowsky10 proposed that the observed effect was due to the prevention or healing of microcracks or holes. Bulychev et a1.14 observed that cracks and voids in initially prestrained copper were healed in the necked region of a tensile specimen upon further straining while under a superposed pressure. Also, pugh5 observed that large cavities were suppressed in copper fractured in tension while under pressure. A second proposal has been forwarded by Beresnev et at al.6 This proposal is based upon the hypothesis that a material fails in a brittle manner because the normal tensile stress reaches a critical value before the shear stress is of sufficient magnitude to cause plastic flow. Since a superposed hydrostatic pressure will increase the ratio of shear to normal tensile stress, a sufficiently high hydrostatic pressure should favor plastic flow while retarding brittle fracture. Galli15 reported that a superposed pressure shifts the ductile-brittle transition temperature of molybdenum. This was explained based upon the reduction of the normal tensile stress by the superposed pressure. Pugh5 explained the occurrence of the observed pressure induced brittle-to-ductile transition in zinc in the same manner. Davidson et al.12 proposed an explanation for the enhancement of ductility by pressure based upon the effects of pressure upon the stress-state-sensitive stages of various fracture propagation mechanisms. Basically, they proposed that pressure will retard cleavage and intergranular fracture by counteracting the required normal tensile stress or will suppress void growth. They observed suppression of intergranular fracture and void growth in magnesium by pressure. Davidson and .Ansell16 reported ductility as a function of pressure for a series of annealed and spheroidized Fe-C alloys. Fig. 2, from this prior work, demonstrates that the effect of pressure upon ductility is structure sensitive in terms of the amount, shape and distribution of the brittle cementite phase. As shown in Fig. 2, in the absence of cementite or when the cementite is in isolated particle form (spheroidized), the ductility-pressure relationship is linear and the slope decreases with increasing carbon content. In the annealed carbon-bearing alloys wherein the cementite is in the form of closely spaced platelets (pearlite) or in the form of a continuous network along prior aus-tenite boundaries (1.1 pct C material), ductility as a function of pressure is nonlinear (polynomial relationship) in which the slope increases with increasing pressure. At the highest pressures studied (22.8 kbars), the slope of the curves for these materials tends to approach those for the spheroidized material of the same carbon content. In this current investigation the change in fracture mechanisms as a function of pressure for the materials shown in Fig. 2 has been examined. The possible connection between the observed effects of pressure upon the fracture mechanisms and the effect of pressure upon ductility is discussed.

Jan 1, 1970

By Frank Firmstone

In the summer of 1842 my father, William Firmstone, was engaged by Charles Jackson, Jr., of Boston, to examine the conditions in the Lehigh valley as a site for blast-furnaces using anthracite for fuel. In consequence of his report, he was further engaged by Mr. Jackson to build a furnace for him and his partners on the Lehigh canal, 2 miles above the mouth of the river at Easton. Work was begun in the fall of 1842, and the first furnace blown-in in 1844. The history of the works, therefore, from 1844 to 1887, when my own connection with them ceased, covers only four years less than the whole period of the rise, culmination, and commencement of the decline in the smelting of iron with anthracite in America, the beginning of which, in a commercial sense, may be put in 1839.' Although this paper, as the title indicates, is concerned almost exclusively with the furnaces at Glendon, still what was done there was more or less influenced by current opinion in the district, and even reflects, to some extent, the changes in opinion and practice with mineral fuel the world over. No. 1 Furnace was built of red brick, on four piers, had three tuyeres and fore-hearth and tymp, as was universal with furnaces using mineral fuel until the introduction of Lurmann's cinder-tuyere. The dimensions and profile are shown in Figs. 1 and 2. The first hearth (Fig. 1) was of sandstone; all after were of fire-brick (Fig. 2). The profile was no doubt derived directly from Gibbons's furnace,2 for it appears from W. Firmstone's note-books that in October, 1840, he visited " Gibbons' new furnaces building at Corbyn Hall," and I have an old drawing,

Jan 1, 1910

By Marie Kinzel

LOS ALAMOS, New Mexico, the birthplace f the atomic bomb, is one of the most famous-and mysterious-places in the world. It leaped into fame on Aug. 6, 1945, when the first atomic bomb burst over Hiroshima. Unheard of until that day, its present life is as hidden from most people as was its very existence in pre-Hiroshima days. Then, those who did know of it dared not breathe their knowledge. "What do you tell your wife when you go to Shangri La?" was the favorite quip of the few consultants who made regular trips from east or west to Los Alamos during the tense months when the bomb was in the making. Security regulations made it impossible even to hint at the rigid secrecy surrounding the project. The puzzled wives in question knew only that their husbands had top priority on airplane flights to Albuquerque. When they had verified the safe arrival of the flight, they undoubtedly breathed a sigh of relief. If they could have visualized the rest of the trip, the sigh of relief would have been replaced by a state of tizzy, until a telegram came saying "Arriving home on Flight X" (on a nice safe airplane).

Jan 1, 1946

By James Kitson, Abram S. Hewitt

I HAVE now the duty—the very pleasant duty—to perform, of presenting to the Hon. Abram S. Hewitt the Bessemer gold medal for distinguished services to the iron and steel trade. When this matter was brought under consideration in London it was well known that, as Mr. Hewitt would be the first to acknowledge, there is more than one man in America upon whom we would gladly have cm ferred this distinction, and to whom this merit might be justly at tributed ; but Mr. Hewitt has been long known to our distinguished members on the other side of the Atlantic as one of the most active minds in the investigation of new methods of manufacture, and one of the most enterprising metallurgists on this side of the Atlantic. Well, gentlemen, we proposed to Mr. Hewitt that he should receive this gold medal, but I think it is quite right, and is his due, that I should state that he at once declined to receive it; and he declined in a manner which rendered it impossible to any one but very per sistent friends and very obstinate Englishmen to refuse. When we heard that our American friends had conferred once more upon Mr. Hewitt the distinction of President of the American Institute of Mining Engineers, and particularly with reference to our contem plated visit, and when we heard that he had been elected unani mously to that position, we felt that we had received the stamp of approval from this side. Gentlemen, as I said before, Mr. Hewitt has long been known to many of us in England as an advocate of scientific education. A report which he made of the metallurgical products at the Paris Exposition in 1867 was one of the matters which drew very clearly and distinctly the attention of the English iron and steel trade to the necessity of further improvement in our technical education as to iron and steel; and it was one of those beginnings which led ultimately to the foundation of the Iron and Steel Institute. The development of the ideas which 'he there investigated undoubtedly led

Jan 1, 1891

By Robert H. Chapman

During the past two years the writer has been traveling in the Lewis and Clarke timber reserve, locating the boundaries and reference-monuments for the Geological Survey. The Lewis and Clarke reserve lies in northwestern Montana. The region is very mouutainous, the main range of the Rocky mountains passing through it, dividing the waters of the Columbia and Missouri rivers. The mountains do not rise in one important and well-defined backbone, but in a series of parallel ridges, striking nearly northwest and southeast. Between these ridges, and, in general, parallel to them, are the drainage-systems. Beginning at the west, the rivers are the Swan, emptying into the Flathead lake, the South fork and the Middle fork of Flathead river, both emptying into the main Flathead river, which, in turn, empties into the lake of that name. The continental divide passes through the reserve from the southeast corner to the middle of the northern boundary, and the stream of most importance east of it is the Sun river, which heads well toward the north, and flows southeasterly and then eastward, and, emerging from the mountains, flows across the great plain of' the Missouri river. The southern boundary is drained by the Big Blackfoot river, flowing westward; the northern boundary, by the several branches of the Flathead river. The accompanying map (which is only a sketch, and does not represent the final work of the Geological Survey in this forest-reserve) shows clearly the parallel systems of drainage and ridges. The westernmost mountain range, the Mission, divides the great valley of the Flathead from the Swan river valley. The

Jan 1, 1900

By J. A. Younkins, J. A. Brooke

In 1931 the Philadelphia Company acquired by lease several coal mines in southern Greene County, Pennsylvania. These mines were known as the "Dora," "Seventh Pool" and "Rosedale" mines in the Sewickley seam, and the "Rosemary," "Seventh Pool" and "Warwick" mines in the Pittsburgh seam. All these mines are in the immediate vicinity of Greensboro, Pa., with considerable river frontage on both sides of that village. The mines in each seam are contiguous and to some extent the properties in the two seams lie one above the other. In 1938 the property known as the "Sandy Run mine," in the Sewickley seam, adjoining the Dora mine, was purchased from the Fredericktown Coal and Coke Co. Altogether, by purchase and lease, the company gained control of approximately 3400 acres of coal land in Greene County, from which it was estimated that some 20,000,000 tons of coal could be extracted. Geology of Warwick Properties Both seams of coal outcrop along or near the river on both sides of the town of Greensbgro. They lie on the eastern slope of the Lambert syncline, near the southern end of the axis, consequently the predominant dip of the seams is away from the river, so that development for river handling has the unavoidable disadvantage of adverse grades for haulage to the outside. Predominant grades away from the river at right angles to the "butt" cleat of the coal average about 2.25 per cent dipping in a westerly direction, but local dips occur, which are considerably greater. Predominant grades parallel to the river and at right angles to the "face" cleat of the coal average about one per cent dipping in a northerly direction. Both seams of coal lie in the Monongahela formation, the Pittsburgh bed being the bottom measure of the formation and the Sewickley bed lying about 90 it. above. Approximately midway between the two lies the Redstone coal bed, which is generally thin and of erratic occurrence and therefore of little commercial value. It is mined only locally where it attains sufficient thickness. Sewickley Bed The Sewickley bed is commonly called the "five-foot" or Mapletown" seam, because in Pennsylvania it reaches its greatest thickness and has been mined most extensively in the vicinity of the village of illapletown, approximately one mile west of Greensboro. In the early development of the Warwick properties, which occurred near the river, the seam had an average of 5 it. 2 in. in height. As development proceeded away from the river, however, the height gradually decreased until the average height of the present workings is about 4 ft. 6 in. Present development is encountering lower coal

Jan 1, 1947

By J. A. Younkins, J. A. Brooke

In 1931 the Philadelphia Company acquired by lease several coal mines in southern Greene County, Pennsylvania. These mines were known as the "Dora," "Seventh Pool" and "Rosedale" mines in the Sewickley seam, and the "Rosemary," "Seventh Pool" and "Warwick" mines in the Pittsburgh seam. All these mines are in the immediate vicinity of Greensboro, Pa., with considerable river frontage on both sides of that village. The mines in each seam are contiguous and to some extent the properties in the two seams lie one above the other. In 1938 the property known as the "Sandy Run mine," in the Sewickley seam, adjoining the Dora mine, was purchased from the Fredericktown Coal and Coke Co. Altogether, by purchase and lease, the company gained control of approximately 3400 acres of coal land in Greene County, from which it was estimated that some 20,000,000 tons of coal could be extracted. Geology of Warwick Properties Both seams of coal outcrop along or near the river on both sides of the town of Greensbgro. They lie on the eastern slope of the Lambert syncline, near the southern end of the axis, consequently the predominant dip of the seams is away from the river, so that development for river handling has the unavoidable disadvantage of adverse grades for haulage to the outside. Predominant grades away from the river at right angles to the "butt" cleat of the coal average about 2.25 per cent dipping in a westerly direction, but local dips occur, which are considerably greater. Predominant grades parallel to the river and at right angles to the "face" cleat of the coal average about one per cent dipping in a northerly direction. Both seams of coal lie in the Monongahela formation, the Pittsburgh bed being the bottom measure of the formation and the Sewickley bed lying about 90 it. above. Approximately midway between the two lies the Redstone coal bed, which is generally thin and of erratic occurrence and therefore of little commercial value. It is mined only locally where it attains sufficient thickness. Sewickley Bed The Sewickley bed is commonly called the "five-foot" or Mapletown" seam, because in Pennsylvania it reaches its greatest thickness and has been mined most extensively in the vicinity of the village of illapletown, approximately one mile west of Greensboro. In the early development of the Warwick properties, which occurred near the river, the seam had an average of 5 it. 2 in. in height. As development proceeded away from the river, however, the height gradually decreased until the average height of the present workings is about 4 ft. 6 in. Present development is encountering lower coal

Jan 1, 1947

By J. M. Camp

In conforniity with the design of the oficials of the United States Steel Corporation for the standardization of the methods employed in the sampling and analysis of all materials encountered in their various lines of manufacture, the Chemists' Committee presents this compilatioti of standard methods for the sampling and subsequent analysis of molten pig-iron. In selecting the methods, the Committee employed the same line of procedure as in former cases, viz., the careful consideration of all the methods employed in each laboratory of the Corporation, evolving therefrom the several methods herein described, the immediate adoption of which is desired. The services of Messrs. W. B. N. Hawk, William Brady, and C. H. Rich, a sub-committee appointed for the preparation of the present paper, are gratefully acknowledged. II. Introduction. A quite obvious cause of nonconformity of results of comparative analyses in the various laboratories of the Corporation has been an apparent lack of uniformity of method in the sampling and analysis of molten iron. This condition is particularly apparent with regard to the determination of the sulphur, numerous discrepancies in which would appear t.o indicate the absence of, and the necessity for, some uniform method of procedure. The estimation of the

Jan 1, 1913

By B. N. Das, P. A. Beck

THE o phases have a complex tetragonal structure with Lo/ao = 0.52 and 30 atoms per unit cell.1 A large number of such phases are now known to occur in various binary systems of the transition elements and they exhibit the following typical features: 2,3 The composition of binary o phases is variable, ranging from approximately A4B to ABI. With only a few exceptions, in the o phases the A-ele-ment comes from the V- or Cr- group of the periodic table, while the B-elements are from the Mn-, Fe-, Co-, or Ni- group. In the first long period the corresponding o phases of the V- and Cr-series have approximately the same compositions. However, as the B-element changes from Mn to Fe to Co to Ni, the mean composition shifts monotonously toward higher A-contents.2-4 For example, if the mean compositions of the various o phases with vanadium are compared with each other, the composition shift mentioned above becomes plainly visible: V 30Mn0 80 Vo.45Feo..,, Vo .,Coo. 45 and Vo.5Nio.3. Similiar composition shifts, although not the same composition values, were observed in u phases formed by second and by third long-period transition elements.3'4 This behavior, very characteristic of o phases, is in rather sharp contrast to the usually quite well-behaved stoichi-ometry of the Laves phases. In the latter, the AB2 stoichiometry predominates, with A the large atom and B the small atom.= The p phase occurs in the four binary systems of Mo or W with Fe or Co. On the basis of their crystal structure determination, Arnfelt and westgren6 ascribed to the p phase in the Co-W system the ideal composition W,Co7. Since all four binary pphases have nearly the same composition, it would seem quite plausible that some definite stoichiometry such as A6B7, might be characteristic of this phase, as AB2 is of the Laves phases. On the other hand, it has been noted,7 that the phases occur at average electron concentrations near to those at which the various cr phases are found. Also, it has been pointed out by Shoemaker and associates8 that structurally the a phases and the p phases are somewhat related to each other; both of these structures may be described in terms of suitable stackings of quasi-hexagonal layers'of atoms. By studying a suitably chosen ter- nary phase diagram, one might expect to be able to find out which one of the two conditions, the analogy with the o phase or the constant ratio between the number of large atoms and the number of small atoms in effect governs the behavior of the p phase. Several isothermal sections of ternary systems containing o phases have been investigated. In all cases where two binary o phases occur, these were found to be connected b a more or less straight ternary o phase field.7' '10 Such elongated o phase fields were also found in ternary systems in which only one of the limiting binaries is known to contain o phase. In this manner a latent o forming tendency could be detected and the virtual composition of a "binary o phase", which does not actually occur as such was approximately determined by extrapolation. The behavior of the phases, including their composition shift, is analogous to that of the classical electron compounds, as described by Hume-Rothery.11 In order to decide whether the p phase is essentially a "size compound" like the Laves phases, where a fixed stoichiometric ratio is quite generally maintained between the "large atoms" and the "small atoms", or whether the p phase is typically an "electron compound" in the same sense as ois, it was decided to investigate an isothermal section of the Mo-Mn-Co system. The Mo-Co system12 and the Mo-Mn system13 each are known to have a binary o phase. It could be therefore expected that a ternary o phase field will connect these two binary cr-phase fields. The p phase is known to occur in the Mo-Co system. If the p phase should turn out to form an elongated phase field extending deep into the ternary system, the following considerations mighto apply. The atomic radius of manganese (1.314for C.N.12) is between the va,lues for Mo (1.40Afor C.N.12) and for Co (1.26Afor C.N.12). If it is assumed that p is a "size compound", and that Mn is substituting for the smaller Co atoms in the p-structure in the ternary system, the y-phase field might be expected to extend parallel to the Mn-Co binary line. If Mn is substituting for the large Mo atoms in the p-structure, the p-phase field may be expected to extend parallel to the Mn-Mo binary line. On the other hand, if the p-phase turns out to be an "electron compound" like o, the ternary p-phase field should extend parallel to the ternary o -phase field connecting (Mo,Mn)owith (Mo, Co) a

Jan 1, 1961

By T. E. Davidson, A. P. Lee

It is known from the early work of Bridgman that the two lowest-pressure transitions (I-II and II-III) are accompanied by substantial and abrupt changes in resistivity and Volume. However, unlike the temperature -induced allotropic transformations observed in such elements as lithium, cobalt, tin, and so forth, there is little actually known about many of the characteristics of the pressure-in&ced transitions. This current work involves an examination of the structural and transformation characteristics of the bismuth I-II and II-III transitions under hydrostatic pressures. The relationship of initial structure to the transformation pressure, rate, resistivity change, and resultant structure is discussed. It is shown that the transition pressure and transformation rate are independent of the presence of grain boundaries and associated anisotropy-induced deformation. An observed hysteresis in both the I-II and II-III transitions is shown. BISMUTH is one of the most interesting of the elements exhibiting pressure-induced polymorphs since it undergoes several allotropic transformations at pressures below 90,000 atm. It is known from the early work of bridman1,2 that the two lowest-pressure transitions (1-11 and 11-111) are accompanied by substantial and abrupt changes in resistance and volume. However, unlike the temperature-induced allotropic transformations observed in such elements as lithium, cobalt, tin, and so forth, there is little actually known about many of the characteristics of these pressure-induced transitions. It is the purpose of this work to examine some of the structural and transformation characteristics of the bismuth 1-11 and 11-111 transitions under hydrostatic pressures. Another interesting characteristic of bismuth is that, in its polycrystalline form, hydrostatic pressures of sufficient magnitude will induce severe progressive plastic deformation in the region of the grain boundaries.3 This deformation, which has also been observed in several other metals, is attributed to the high degree of anisotropy in the linear compressibility of bismuth, resulting in shear stresses in the grain boundaries when it is exposed to hydrostatic pressure. Most thermally induced allotropic transformations in metals, whether of the diffusionless ather-ma1 (martensitic) or isothermal nucleation and growth types, are dependent upon structure and prior history,4 viz., grain boundaries, deformation, and so forth. One logically wonders then whether the transformation characteristics of the pressure-induced polymorphs in bismuth might also depend upon initial structure, particularly with respect to the presence of grain boundaries and associated plastic deformation. In this investigation, the role of grain boundaries and plastic deformation on the characteristics of the bismuth I-II and 11-111 transitions will be established. The rather unique residual microstruc-tural changes associated with these transitions will be presented and discussed. The occurrence of a measurable hysteresis in both the I-II and 11-111 transitions will be demonstrated. The type of transformation mechanism based on the observed transformation rate will be discussed. EXPERIMENTAL PROCEDURE A) Apparatus. The hydrostatic pressure system utilized in this investigation is similar to that previously reported by Bridgman' and Birch and Robertson,5 and has been previously described.3 For the purpose of this work, the pressure medium utilized was a 1:l mixture of pentane and isopentane. Pressure measurement was by means of a manganin coil in conjunction with a Foxboro Recorder. The manganin coil was mounted in the bottom closure and inserted inside the pressure cavity. Based on calibration against a controlled clearance piston gage at approximately 10,000 atm, the estimated error in the pressure measurement was +2 pct. Assuming the nonlinearity in the pressure coefficient of resistivity between 10,000 and 28,000 atm to be not greater than 1 pct, then the estimated error in the range of the I-II and 11-111 transitions was +3 pct. B) specimen Material and Preparation. The bismuth utilized throughout this investigation was of

Jan 1, 1964

TO THE. BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN Submitted herewith are the report of the Treasurer for the year 1945 and reports for the same year of the following committees: Membership, Admissions, Papers and Publications, Mining and Metallury (Magazine), and Library. In this review of the year by the Secretary reference frequently will be made to the "Paul" Committee and to the "hotter" Committee. The first is the special committee on Divisional Relationships and the second the special Committee on Ways and Means. These two important committees, appointed by President Harvey S. Mudd under authorization of the Board of Directors on March 21, 1945, were composed as follows:

Jan 1, 1946

By Charles F. King

The only investigations on record of the reactions occurring (luring the Bessemer blow are of charges containing a large percentage of manganese, with the exception of' two partial analyses by Snelus and Barker of the English method, where a low percentage of manganese was used. They do not give the analysis of the spiegel, [lor do they report any graphitic carbon after the first stage of the process. Both report only traces of manganese after the first stage until the addition of spiegel. The slags corresponding to the samples of metal were not analyzed.

Jan 1, 1881

By R. W. Gurry

THERMODYNAMIC calculations indicate that boron is a better deoxidizer than silicon but probably is not quite as effective as aluminum. Boron should, therefore, be readily oxidized out of the open-hearth bath, which implies that it is not recovered in significant concentration from any scrap charged; also that, if added in the ladle, it tends to oxidize out during teeming unless protected by the presence of a. better deoxidizing agent. These conclusions do not apply to liquid cast iron, in which the oxygen content is much lower than in liquid steel. The possibility of conserving certain strategic alloying elements widely used in steelmaking, notably manganeie, chromium and molybdenum, by the use of boron, which in small concentration appears to be extraordinarily effective in promoting hardenability, raises a question as to what extent any boron present in the scrap charged into the open hearth is oxidized out during melting and subsequent refining. This question is significant because the optimum concentration of boron in the finished steel, which is fairly critical, would be very difficult to attain if the boron in the charge were largely retained in the metal. Moreover, unless boron is substantially eliminated in the open-hearth process its use on a large scale would eventually make it impossible to produce boron-free steel except by restricting the charge to virgin material. There is at present, unfortunately, virtually no satisfactory direct evidence to provide an answer to this question; but there are indications from practice that boron is oxidized out in the open hearth in the production of medium or low-carbon steel, although it may be retained if the carbon content remains fairly high; that is, if the oxygen is kept fairly low. In the absence of direct data, it is necessary to rely upon the indications of indirect evidence, the best approach now available being a thermodynamic calculation of the deoxidizing power of boron in liquid steel by the general method used so successfully by Chipman1 in his study of the reactions in the open-hearth process. The thermal data for boron, upon which such a calculation must be based, are reasonably satisfactory; the only quantities not directly determined are the entropy of melting of boron, the activity coefficient of boron in liquid steel, and the activity coefficient of B203 in an open-hearth slag; but these values may be estimated with ample accuracy. The results of this calculation, which is presented later, are given in Table I, together with corresponding data for other deoxidizing elements. This table shows the calculated residual content of oxygen in equilibrium with different residual concentrations of the deoxidizer in the metal;

Jan 1, 1943

By James Douglas

At this last meeting of our Institute for the year 1899, it is appropriate that we should look back at the past. To review the century's progress in the exact sciences and the resulting arts that fall within the scope of our labors is beyond my ability. But I wish to draw your attention to some phases of that progress, almost as important, which lie within the zone of sociology, touching at so many points the domain of applied technology. One of these is suggested by the library of technical literature which this century has produced —not the least important contribution to which is our own Transactions. The nineteenth century has witnessed the beneficial spread of democracy in politics. Under the impulse, to no small degree, of the same spirit, there has grown up a brotherhood of fellow-workers and a sense of fellow-ownership in the secrets of nature. Though the Patent Office has assumed such proportions as to hare become a source of national revenue, and a multitude of inventors, great and small, are seeking through its agency to secure some pecuniary profit from their devices, there is even greater eagerness among both interested and disinterested workers in the field of technology to publish their observations, and even their discoveries, and to give them to the world without remuneration. The motives influencing the great body of writers who, without any pay, use the technical journals and such media of communication as our Transactions, in order to give to the brethren of their craft the results of

Jan 1, 1900