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By Alfred Boyles

"Heredity"1 in cast iron has been a subject of much discussion. Numerous experimenters have found that the properties of gray iron may vary greatly without corresponding variations in composition or thermal treatment. The main structural difference in such cases is in the size and distribution of the graphite flakes and the explanations given usually attribute this difference to some chemical element not shown by ordinary analysis or to some physical factor, such as inclusions in the melt. It cannot be said that any of these theories is completely satisfactory. Much remains to be learned about cast iron and for this reason a study of the material was undertaken as a part of the program of fundamental research at Battelle Memorial Institute. A review of the literature indicated that very little systematic work had been done on the mechanism of freezing in cast iron. The experiments described below are largely concerned with that problem. Normal and "Dendritic" Cast Iron As examples of variation in type of structure, photomicrographs of two test bars of cast iron are shown (Figs. 1 and 2) and the composition and properties are given in Table 1. Both are common, unalloyed gray iron. Test bar No. 13 has normal graphite flakes while No. 49 has very fine, lacy graphite arranged in a dendritic pattern, the matrix in both being pearlite. These two types of cast iron are well known to foundry-men and need no detailed description.

Jan 1, 1937

By Louise Reber

THE town of Jerome is located in Yavapai County in north central Arizona. It has a population of over 6000 people and the two important mines of the district, the United Verde and the United Verde Extension, lie almost within its limits. Perched high on the southwest side of the Verde Valley, at elevations of 4800 and 5500 ft.. (1463 and 1676 m.), both mines have long tunnels from their lower levels through which ore is hauled to their respective smelters. The two smelter towns of Clarkdale and Verde, out in. the center of the valley and about 2000 ft. (609 m.) below, form part of the wide panorama that meets the eye at Jerome. This panorama and the topographic and surface features and the geologic formations are shown in a separate pamphlet. In the vicinity of Jerome, the great southern escarpment of the Arizona plateau forms the northeast side of the Verde valley. The general level of this escarpment, or "the rim" as it is called, is about 4000 ft. above the Verde River. A corresponding elevation is reached only by the, highest parts of the Black Hills, which bound the valley to the southwest. The two lava-capped mesas, known as Mingus and Woodschute Mountains, form the culmination of the Black Hills. That part of the old Black Hills mining district which lies between their crests -and the Verde River is now known as the Jerome or Verde copper district. However, if the smelters are not included, a strip about 7 mi. long and 3 mi. wide (11 by 5 km.) embraces practically all the properties belonging to the Jerome district. This strip lies parallel to and along the side of the Verde valley from about First View, 2 mi. northwest of Jerome, to the neighborhood of Allen Spring, near the south end of Mingus. Mountain. The rank of the district in copper production, as well as features of peculiar geologic interest in connection with the ore occurrences, entitle the district to much more consideration than it has received in the literature of copper mining. Arizona stands preeminent as a copper-producing state. In 1918, it produced four-tenths of the total amount produced in the United States, and nearly equaled the, combined production of its three chief competitors, Montana, Michigan, and Utah. The production of the Jerome district places it in the sixth place among the copper

Jan 8, 1920

Aamot, Olav Crone, Chem. Engr., Norsk Elektrokemisk, Kongensgt. 18, Olso. Norway. '29 Abadilla.-Quirico A., Dir., Bureau of Mines Manila, P. I. '38 Abbott, Clarence E., V.P., Charge of Raw Materials, Tennessee Coal, Iron & R.R. Co., 1212 Brown-Marx Bldg., Birmingham, Ala. '04 Abel, Raymond L., Prof., Dept. of Pet. Refin., Univ. of Pittsburgh Pittsburgh, Pa. '29 Abel. Walter D., Cons. Engr 1839 Holmby Ave., W. Los Angeles. Calif. '32 Abele, Louis T R. F. D. 5. Susquehanna Trail, N., York. Pa. '31 Abell, Leo M., Ore Dressing Investigator, School of Mines Adelaide, S. Australia. '31 Abenius. Hakan V., Mine Supt., Bolidens Gruvaktiebolag Boliden, Sweden. '37 Aborn, Robert H., Asst Met., Research Lab., U. S. Steel Corp. Lincoln Highway, Kearny, N. J. '19 Abraham, W. E. V., East India United Service-Club, 16 St. James' Sq., London, S. W. 1, England. '28 Abrams. Charles Jackson 1624 17th St., Denver, Colo. '36 Abstein, Henry T., Engr. & Mgr., Profile-Tamarack Mines Co Yellow Pine, Idaho. '27

Jan 1, 1938

Jan 1, 1970

By Joklik, G. F.

Most publicity about the copper industry nowadays is focused on the adequacy of ore reserves and on excessive mining capacity. These concerns, stemming from public awareness of actual and potential shortages and oversupplies, relate to production rather than consumption. Perhaps the reason for this one-sided view is that copper is thought of as a commodity which is conspicuously traded in world markets, rather than as one of many industrial materials that serve today's rapidly changing technology. Copper differs from other widely traded commodities in that its real cost of production has progressively increased since World War 11. The reasons for the increase are identifiable by analyzing operations in one of the world's large producing centres, the copper province of Arizona. Another respect in which copper differs from some other commodities is that increases in demand occur less automatically in the case of copper than they tend to in commodities whose consumption is more directly related to population growth. The copper industry's current inability to generate and attract needed investment capital is attributable to these differences between copper and other commodities; it suggests that the concept of copper purely as a commodity is outdated. The key to the problem is better integration between the activities of copper producers and users. Depending on circumstances, integration takes various forms- for example, investment tied to long-term sales con- tracts between producers in developing countries and consumers overseas; common ownership of producing and manufacturing facilities in industrialized nations like the U.S.; and consumer-oriented research and marketing by the copper producers.

Jan 1, 1978

By Henry M. Howe

PART I. § 1. Introduction. After giving certain definitions, this paper gives the reasons which led to Roozeboom's form of the diagram of the freezing-point curves and general equilibrium of the iron-carbon compounds, steel and cast-iron ; and then those which led to replacing it with the present or double diagram, in which graphite is at all temperatures held to be the more stable and cementite the less stable (metastable) form of carbon. Next in § 10 the evidence supporting this greater stability of graphite is examined, then in § 17 that which seems to oppose it, and in § 22 a summary of the evidence is presented. The second part of the paper considers the topography of the graphite-iron diagram, rejecting summarily the solubility-lines based on the data of Charpy and Grenet and of Mannes-mann, on the ground that the data even on their face do not really point toward these lines, and that they are wholly incompetent to determine any solubility-lines whatsoever, because they report together with the dissolved carbon also an indeterminate quantity of cement-carbon, and because even such carbon as is actually dissolved, only in part represents the solubility of graphite, and in another and indeterminate part represents the solubility of cementite, or at least of carbon in presence of cementite as distinguished from graphite. It might be thought that graphite is but slightly soluble in iron, because of the absence of any suggestions of eutectoid graphite, corresponding to the eutectoid cementite of pearlite in very many cases in which the cast-iron seems to consist of ferrite and massive graphite only, and because of the micrographs of Goerens and Gutowsky. In these the primary austenite of cast-iron quenched but little below the eutectic freezing-

Jan 7, 1908

Jan 1, 1968

By Shiou-Chuan Sun

DISCUSSION shiou-chuan sun (author's correction) - Too late for revision, the author realized that the data on stability of froth presented in this paper were not based on the same height of froth column. It is recommended herein that the stability of froth is better calculated by dividing the time elapsed until the froth disappeared by the volume (in cu cm per sq cm) or height of the froth column, and is expressed in sec per cm. The stability data in Tables I, II, and III of this paper were recalculated, in accordance with this recommendation, and the results are shown respectively in the accompanying Tables VII, VIII, and IX. Compared with Tables I, II, and III of the paper, the stability data of Tables VII, VIII, and IX are more reliable in disclosing the persistence of froth of various frothers having different frothabilities. For example, the conclusion given in the paper that the stability of froth is generally proportional to the volume of froth becomes invalid when the stability of froth is expressed in sec per cm, as shown in Tables VII, VIII, and IX. Table VII shows that both the stability and volume of froth increase with the addition of small amounts of n-hexyl alcohol, and that further additions of n-hexyl alcohol decrease the stability but increase the volume of froth. Table VIII indicates that the stability of different types of frothers is governed by their chemical composition and is difficult to predict from their frothability. Table IX shows that the stability of different frothers with similar nonpolar groups tends to increase with a decrease of the hydro- philic property of their polar groups, and consequently with the decrease of their solubilities. This is further substantiated by the fact that the stability of frothers, as listed in Table IX, is generally lowered by the solvent effect of absolute ethyl alcohol. Table IX shows also that the stability of froth tends to increase with the decrease of the volume of froth* provided the frothers used have similar nonpolar groups and dissimilar polar groups.

Jan 1, 1953

By Shiou-Chuan Sun

DISCUSSION shiou-chuan sun (author's correction) - Too late for revision, the author realized that the data on stability of froth presented in this paper were not based on the same height of froth column. It is recommended herein that the stability of froth is better calculated by dividing the time elapsed until the froth disappeared by the volume (in cu cm per sq cm) or height of the froth column, and is expressed in sec per cm. The stability data in Tables I, II, and III of this paper were recalculated, in accordance with this recommendation, and the results are shown respectively in the accompanying Tables VII, VIII, and IX. Compared with Tables I, II, and III of the paper, the stability data of Tables VII, VIII, and IX are more reliable in disclosing the persistence of froth of various frothers having different frothabilities. For example, the conclusion given in the paper that the stability of froth is generally proportional to the volume of froth becomes invalid when the stability of froth is expressed in sec per cm, as shown in Tables VII, VIII, and IX. Table VII shows that both the stability and volume of froth increase with the addition of small amounts of n-hexyl alcohol, and that further additions of n-hexyl alcohol decrease the stability but increase the volume of froth. Table VIII indicates that the stability of different types of frothers is governed by their chemical composition and is difficult to predict from their frothability. Table IX shows that the stability of different frothers with similar nonpolar groups tends to increase with a decrease of the hydro- philic property of their polar groups, and consequently with the decrease of their solubilities. This is further substantiated by the fact that the stability of frothers, as listed in Table IX, is generally lowered by the solvent effect of absolute ethyl alcohol. Table IX shows also that the stability of froth tends to increase with the decrease of the volume of froth* provided the frothers used have similar nonpolar groups and dissimilar polar groups.

Jan 1, 1953

By Open-Hearth Steel

I received a telegram yesterday from Mr. J. H. Nead saying that he regretted circumstances had come up which prevent his attending the meeting, but that arrangements have been made and Mr. T. S. Washburn, of Inland Steel, will act as the Co-Chairman in his stead. We are sorry, of course, that he cannot be here at this conference. We have, therefore, asked Mr. James J. Bowden, chief metallurgist of Republic Steel Corporation, Cleveland, to act as Chairman and Mr. Tom Washburn to act as Co-Chairman. I will turn the meeting over to these gentlemen at this time.

Jan 1, 1940

Jan 1, 1888

By J. J. Forbes

Probably the newest thing in mining safety, or safety for mines, is the apparent dissatisfaction on the part of the mineral industries, as represented by both management and labor, and the general public of the Nation, with the safety record of the mining industry. This is reflected by published comments and papers in the technical press;1-8 in labor periodicals, 10 11 in popular journals and periodicals,12 13 and in the daily press; also by discussions of the Safety Committees sponsored by the National Safety Council, 9, 14-15 the American Mining Congress, 1, 16 the American Institute of Mining and Metallurgical Engineers, 2, 4 the Mine Inspectors' Institute of America,6,8,17,18 the Coal Mining Institute of America, 5, 19, the American Standards Association, and others.20,21

Jan 1, 1949

By Elwin L. Fisk

The Cordero mine is located in the Nevada portion of the Opalite Mining district that straddles the Oregon-Nevada state boundary. The mercury deposits of the district occur along the margins of the broad east-west graben valley of McDermitt Creek. The only other major producers, the Opalite and Bretz mines, on the northern margin of the graben have thus far exploited only shallow deposits within 100 feet of the surface. Through December 1965, Cordero has produced 94,680 flasks of mercury, the most of which came from the large underground cinnabar deposit. Nearly all of the mercury ore deposits in this district have been found in Miocene rhyolitic intrusives, flows, tuffs, and lake beds. These rhyolites have been argillically altered at depth and extensively silicified at or near the surface. These silicified areas or "opalite" masses were the original cinnabar-bearing outcrops.

Jan 1, 1968

By Alfred V. de Forest

WE are now assembled in this hall for the eighteenth lecture in honor of the memory of our greatest American metallurgist, Henry Marion Howe. Many of his most intimate contemporaries, led, as was fitting, by Professor Sauveur, have described his vital accomplishments in three fields: as a leader in technical industrial development; in theoretical research; and finally as a teacher and source of inspiration for nearly two generations of students. In 1914 Professor Howe had retired from active teaching, but maintained his laboratory at Columbia University under the care of Arthur G. Levy, with whom he published many of the papers that later were incorporated into his last book, "The Metallography of Steel and Cast Iron." My position at the time was that of personal assistant to Professor Campbell-no pay, no duties, but the great privilege of preparing specimens, taking pictures and attending to some of the current consulting work. Whenever possible, I visited Howe's laboratory to chat with Levy and gather ideas about the wonderful field of metallography-in which I was a rank amateur, rescued by the quiet enthusiasm of Donald Smith of Princeton from an instructorship in civil engineering. Levy let me act as a fly on the wall during the Professor's occasional visits. Busy as he was, Professor Howe took the time and trouble to encourage my interest, as he had done for hundreds of others. He told me how he went about gathering his own information speculating as to causes, considering experiments, and verifying his conclusions. I ventured to mention some tests I had run on the irregular stretching of wires of different metals. He read the small volume I had prepared of ill-assorted facts and fancies and remarked: "Nobody cares for your theories or the history of your tests. Describe what you found as briefly as possible and perhaps I can help you to publish." Curiously enough, among my discards were some autographically recorded load-versus-electrical-resistance measurements. Taken with inadequate knowledge and equipment, these curves did not reproduce consistently, but if the relationship between strain and resistance had then been explored, the latest type of strain gauge might have been in useful service for the past 25 years. Professor Howe was a gifted teacher, perhaps because he was primarily an ardent and assiduous student. His own eagerness to learn and his willingness to revise and extend his opinions constantly encouraged those of his environment to be diligent and painstaking in the pursuit of knowledge. In honoring his memory, I also wish to bring to mind the kindly, humorous and quiet Levy, and join his name again, as it was for too brief a space in the past, with that of many-sided Henry Marion Howe. FACTORS OF IMPACT STRENGTH The subject chosen for the Howe Memorial Lecture by Dr. Gillett last year

Jan 1, 1941

By Jack F. Harang, P. B. Leavenworth

Development during the year 1941 on the Texas Gulf Coast resulted in the dis covery of 27 new fields as compared to 26 fields for the year 1940. Drilling.—During the year, 1405 wells were drilled. Of this number, 1031 were completed as oil wells with 375,000 bbl. daily of new production; 50 were com pleted as gas wells and 324 were failures. The most active area was Jackson County, where 375 wells were drilled and 336 of them accounting for 190,000 bbl. daily of new production. Types of Fields.—Of the 2 7 new fields, 14 are considered to be oil fields, 8 are listed as gas-distillate fields and 5 as gas fields. This may be compared to 26 fields found in 1940, of which 14 were oil fields and 12 gas-distillate fields. Producing Sections.—Frio discoveries retained their predominant position by having 10 Frio fields discovered in comparison to 6 fields in the Wilcox, 4 in the Yegua, 5 in the Miocene and 2 in the Jackson. In the previous year 15 Frio fields were found, 4 in the Wilcox, 2 each in the Yegua, Cook Mountain and Miocene, and I in the Jackson. Production.—Production increased over 1940 approximately 10 per cent, being 113,726,893 bbl. for the year 1941 and 104,127,247 bbl. for 1940. The statistics in Tables I and 2 include distillate and condensate as oil production because no separate reports have been compiled. It is hoped that this separation may be possible some day, but as a great many fields produce both oil and distillate and these arc commingled in pipe lines, separation of statistics will be more difficult than for other areas. New Fields Big Hill, Jefferson County.—Stanolind Oil and Gas Company's No. I George D. Anderson was completed as a gas well from a Frio sand at 8705 to 8720 ft., on Dec. 24, 1941, after having been drilled to a depth of 9500 ft. Additional development is being carried on but it is not possible to evaluate this discovery at this time. Brushy Creek Field, Lavaca County.— Shell Oil Corporation's No. I D. G. McManus was completed as the discovery well in the Brushy Creek field on Oct. 29, 1941, from a Wilcox sand through perforations at 7225 to 7230 ft., making gas and 180 bbl. of 59° gravity distillate. This well was bottomed at 10,998 ft. in the Wilcox. No statement can be made at this time as to the importance of this discovery. Chenango Field, Brazoria County.—J. N. Rayzor et al. completed their No. I Sarah J. Christian through perforations at 8564 to 8572 ft. in a Frio sand, for 453 bbl. of 37.7° gravity oil, on Feb. 6, 1941, after having drilled to 9564 ft. Several wells were drilled in this area during the year but failed to establish important production. This is considered a minor discovery. Clodine Field, Fort Bend County.—Providence Oil Company's No. I Hatfield was the discovery well of the Clodine field, being completed through perforations at 7499 to 7502 ft. for 108 bbl. of 51.2° gravity distillate, on June 19, 1941. The well was bottomed at 8090 ft. Several wells

Jan 1, 1942

By P. B. Leavenworth, Jack F. Harang

Development during the year 1941 on the Texas Gulf Coast resulted in the dis covery of 27 new fields as compared to 26 fields for the year 1940. Drilling.—During the year, 1405 wells were drilled. Of this number, 1031 were completed as oil wells with 375,000 bbl. daily of new production; 50 were com pleted as gas wells and 324 were failures. The most active area was Jackson County, where 375 wells were drilled and 336 of them accounting for 190,000 bbl. daily of new production. Types of Fields.—Of the 2 7 new fields, 14 are considered to be oil fields, 8 are listed as gas-distillate fields and 5 as gas fields. This may be compared to 26 fields found in 1940, of which 14 were oil fields and 12 gas-distillate fields. Producing Sections.—Frio discoveries retained their predominant position by having 10 Frio fields discovered in comparison to 6 fields in the Wilcox, 4 in the Yegua, 5 in the Miocene and 2 in the Jackson. In the previous year 15 Frio fields were found, 4 in the Wilcox, 2 each in the Yegua, Cook Mountain and Miocene, and I in the Jackson. Production.—Production increased over 1940 approximately 10 per cent, being 113,726,893 bbl. for the year 1941 and 104,127,247 bbl. for 1940. The statistics in Tables I and 2 include distillate and condensate as oil production because no separate reports have been compiled. It is hoped that this separation may be possible some day, but as a great many fields produce both oil and distillate and these arc commingled in pipe lines, separation of statistics will be more difficult than for other areas. New Fields Big Hill, Jefferson County.—Stanolind Oil and Gas Company's No. I George D. Anderson was completed as a gas well from a Frio sand at 8705 to 8720 ft., on Dec. 24, 1941, after having been drilled to a depth of 9500 ft. Additional development is being carried on but it is not possible to evaluate this discovery at this time. Brushy Creek Field, Lavaca County.— Shell Oil Corporation's No. I D. G. McManus was completed as the discovery well in the Brushy Creek field on Oct. 29, 1941, from a Wilcox sand through perforations at 7225 to 7230 ft., making gas and 180 bbl. of 59° gravity distillate. This well was bottomed at 10,998 ft. in the Wilcox. No statement can be made at this time as to the importance of this discovery. Chenango Field, Brazoria County.—J. N. Rayzor et al. completed their No. I Sarah J. Christian through perforations at 8564 to 8572 ft. in a Frio sand, for 453 bbl. of 37.7° gravity oil, on Feb. 6, 1941, after having drilled to 9564 ft. Several wells were drilled in this area during the year but failed to establish important production. This is considered a minor discovery. Clodine Field, Fort Bend County.—Providence Oil Company's No. I Hatfield was the discovery well of the Clodine field, being completed through perforations at 7499 to 7502 ft. for 108 bbl. of 51.2° gravity distillate, on June 19, 1941. The well was bottomed at 8090 ft. Several wells

Jan 1, 1942

Page The Cobaltchromium Binary System (paper by A. R. Elsea, A. B. \Yesterman, and G. K. Manning, Met. Tech. June, 1948, Mechanism of Precipitation in a Permanent Magnet Alloy (paper by A. H. Geisler and J. B. Newkirk, Met. Tech. Aug. 1948, Tp 2444)................................................................................................. 300 Some Effects of Applied Stresses on Precipitation Phenomena (~aper by W. L. Finlay and W. R. Hibbard, Jr., Met. Tech. Sept. 1948, Tp 2470)....................................................................................... 301 Diffusion of Carbon in Austenite with a Discontinuity in Composition (paper by L. S. Darken, Met. Tech. Sept. 1948, TP 2443) 304 An Electron Diffraction Study of Oxide Films Formed on Nickelchromium Alloys (paper by J. W. Hickman and E. A. Gul- bramen, Met. Tech. June 1948, Tp 2372)..................................................................... 305 An Electron Diffraction Study of Oxide Films Formed on Copper-nickel Alloys at Elevated Temperatures (paper by J. W. Hickman and E. A. Gulbransen, Met. Tech. June 1948, TP 2391)................................................ 307 Decarburization of Chrome Nickel Alloys by Their Surface Oxides in High Vacua and at Elevated Temperatures (paper by E. A. Gulbransen, W. S. Wysong, and K. Andrew, Met. Tech. Sept. 1948, TP 2438)................................ 307 Fractographic Study of Cast Molybdenum (paper by C. A. Zapffe, F. K. Landgraf and C. 0. Worden, Met. Tech. Aug. 1948, TP 2421)................................................................................................. 308 Effect of Composition on Grain Growth in Aluminum-magnesium Solid Solutions (paper by L. J. Demer and P. A. Beck. Met. Tech. June 1948, TP 2374)............................................................................. 309 Effect of a Dispersed Phase on Grain Growth in Al-Mn Alloys (paper by P. A. Beck, M. L. Holzworth and P. Sperry, Met. Tech. Sept. 1948, TP 2475)................................................................................. 310 Statistical Rate Theory of Metals—Mechanism of Flow and Application to Tensile Properties (paper by J. W. Fredrickson and H. Eyring, Met. Tech. Aug. 1948, TP 2423)............................................................... 315 Nucleation of Slip Bands (paper by J. G. Leschen, R. P. Carreker, and J. H. Hollomon, Met. Tech. Sept. 1948, TP 2476) and.. 318 Transient Plastic Deformation (paper by R. P. Carreker, J. G. Leschen, and J. D. Lubahn, Met. Tech. Sept. 1948, TP 2477).. 318 Plastic Deformation of Large Grained Copper Specimens (paper by W. R. Hibbard, Jr., Met. Tech. Sept. 1948, TP 2469). ... 323 Plastic Flow in Anisotropic Sheet Steel (paper by L. R. Jackson, K. F. Smith, and W. T. Lankford, Met. Tech. Aug. 1948, TP 2440)................................................................................................. 323 The Effect of Thermal-mechanical History on the Strain Hardening of Metals (paper by J. E. Dorn, A. Goldberg, and T. E. Tietz, Met. Tech. Sept. l948, TP 2445)....................................................................... 325 The Room and Elevated Temperature Properties of Some Sand Cast Magnesium-base Alloys Containing Zinc (paper by T. E. Leontis, Met. Tech. June 1948, TP 2371)..............................................................., 327 The Low Temperature Properties of Tin and Tin-lead Alloys (paper by H. S. Kalish and F. J. Dunkerley, Met. Tech. Sept. 1948, TP 2442)............................................................................................335 Thermal and Electrical Properties of Ductile Titanium (paper by E. S. Greiner and W. C. Ellis, Met. Tech. Sept. 1948, TP 2466).................................................................................................... 335 Property Changes during Aging (paper by A. H. Geisler, Met. Tech. Aug. 1948, TP 2436)............................... 337 Factors Affecting the Tensile Notch Sensitivity of Magnesium Alloy Extrusions (paper by I. Cornet, Met. Tech. Aug. 1948, TP 2419)................................................................................................. 338 Effect of Grain Size on Tensile Strength, Elongation and Endurance Limit of Deep Drawing Brass (paper by H. L. Walker and W. J. Craig, Met. Tech. Sept. 1948, TP 2478)............................................................. 339 A Copper-base Alloy Containing Iron as a High-strength, Highconductivity Wire Material (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Met. Tech. Aug. 1948, TP 2422).............................................. 340 A High Strength-High Conductivity Copper-silver Alloy Wire (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Mel. Tech. June 1948, TP 2366)...................................................................... 340 The Effect of Chronlium on the Ma Point (paper by J. B. Bassett and E. S. Rowland, Met. Tech. Aug. 1948, TP 2417.... 341 The Kappa Eutectoid Transformation in the Copper-silicon System (paper by W. R. Hibbard, Jr., G. H. Eichelman, Jr., and W. P. Saunders, Met. Tech. Sept. 1948, TP 2441).............................................................. 343 Stabilization of the Ausknite-martensite Transformation (paper by W. R. Harris, Jr. and M. Cohen, Met. Tech. Sept. 1948, TP 2446)................................................................................................ 344 Secondary Hardening of Tempered Martensitic Alloy Steel (paper by W. Crafts and J. L. Lamont. Mel. Tech. Sept. 194,8, TP 2439)................................................................................................. 345

Jan 1, 1950

By A. E. Seaton

In this paper it will be my endeavor to trace the development of the marine engine and its appurtenances, and the general progress that has taken place in marine engineering generally during the past fifteen years, rather with the object of attributing much of it to the successful efforts of the makers of iron and steel, thereby rendering my thanks to them for the valuable service they have contributed to my profession, than to recount what has been achieved by the skill, ability and perseverance of my colleagues in shipbuilding and engineering. The engineer has been at all times dependent on the ironmaster, and on more than one occasion his progress has been barred by the inability of the latter to overcome some obstacle to success in his manufacture. But on the other hand, it is equally true that the ironmaster has often been ahead of the engineer, and has been prepared, long beforehand, to supply that which would make a success for the marine engineer if he would avail himself of it.

Jan 1, 1891

By B. A. Kulp, R. R. Reeber

Lattice parameters for the wurtzite form of' CdS mere measured by powder X-ray diffraction techniques over the temperature range 26° to 1000 K'. A negative thermal -expansion coefficient was determined parallel and perpendicular to the c axis below 13.5°K. Near 808°K, the curves of the a, parameter, the differential thermal expansion, and the resistivitv vs absolute temperature exhibited a reversible discontinuity. j\. direct determination of the lattice parameters of CdS over an extended temperature range is of particular use in interpretation of the effects of high pressure on the band structure of semiconductor materials. For example, Langer' has studied the effects of pressure on the absorption edge of CdS from 77°K to room temperature. In order to properly interpret his results it is necessary to know the change in lattice constants as a function of temperature for the wurtzite, zincblende, and rocksalt2 modifications of this material. Thermal-expansion measurements for CdS, wurtzite phase, have previously been determined over a limited temperature range.s74'5 The zincblende phases, of other compounds with similar bonding, have been investigated by Novikova et a! .'' Previous thermal-expansion measurements for metals with hexagonal symmetry have for the most part used bulk sample techniques for low-temperature result. Most X-ray measurements at low temperature have been on materials with cubic symmetry.'jQ The use of X-ray powder-diffraction techniques offers a convenient and accurate method of measurement over a wide temperature range. The X-ray method, besides measuring unit cell size, also provides information about change in structure type and the nature of some of the stacking defects present. I) EXPERIMENTAL PROCEDURE The thermal expansion was measured by X-ray powder-diffraction techniques. Lattice parameters for the range 300" to 1000°K were determined in a 19-cm Unicam camera. From 26" to 300°K a 34-cm back-reflection camera with the Van Arkel" film arrangement was used. The sample was bonded to a copper cold finger below a helium, hydrogen, nitrogen, oxygen, dry ice, or ice brine bath in a metal cryistat. che inner bath was surrounded by another one for radiation shielding. Nitrogen was used in this outer bath for the very low-temperature runs while dry ice and acetone was used for the 195°K point. CuKa X-rays, filtered with a nickel foil, entered the cryostat through a 0.001-in.-thick aluminum window. During a typical 9-hr exposure the sample was continuously rotated through a 30-deg arc. Heat losses from the sample holder limited the minimum temperature attained to 26°K with helium in the inner dewar. Temperature calibration between 25" and 125°K was determined with an Allen Bradley 300-ohm carbon resistor. The resistor was attached to the back of the copper finger with a thin layer of silicone grease. Liquid He, HZ, N2, and O2 baths were used to calibrate the resistor. Temperature variation is estimated to be *2"K with a slightly higher uncertainty at room temperature and 264°K. The thermal expansion of high-purity germanium from 373" to 900°K was measured as a calibration for the Unicam camera. This value was compared with the known value1' for the thermal expansion. A discontinuity in the thermal-expansion coefficient of the CdS a, parameter was observed. Similar discontinuities in the resistivity and differential thermal analysis at the same absolute temperature indicate that the temperature error is *5°K in the temperature range above 500°K. Temperature errors in the Unicam camera below 500°K are appreciably higher due to large gradients in the resistance furnace. II) SAMPLE PREPARATION The CdS was Eagle Picher ultrapure grade. The crystallite size range of the as-received powder

Jan 1, 1965