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By J. W. Halley

THE effects of tin on steel have become increasingly important because of the necessity of using poorly detinned scrap, tin cans, and terne plate, in the open hearth. Since a tin can contains about 1.5 per cent tin, it would be possible to have up to 0.75 per cent tin in steel made with a 50 per cent scrap charge. In order to use tin-containing scrap, it is necessary to know the effect of tin on various grades of steel. The following investigation is by no means comprehensive but covers a number of steels in which tin content is important. PUBLISHED WORK A number of investigations of the effects of tin on rolling quality and physical properties have been published. It has been found that tin increases strength and hardness and reduces ductility and notched impact resistance. The decrease in ductility and notched impact resistance becomes more marked as the carbon decreases. McKimm1 found no change in Olsen ductility, Rockwell hardness, yield strength, tensile strength or elongation in cold-reduced strip containing up to 0.124 per cent tin. A tin content of 0.15 per cent gave difficulties in rolling and increased the hardness but 0.21 per cent tin showed no change in properties from material containing very little tin. No explanation of this contradiction is offered. Andrew and Peile2 investigated steels containing 0.10 to 0.25 per cent carbon and up to 0.63 per cent tin. They found an increase in tensile strength 0f from 100 t0 200 lb. per sq. in. for each 0.01 per cent tin on normalized samples. The elongation and reduction of area were decreased and the notched impact resistance was reduced markedly. Quenched and drawn samples did not show embrittling if water-quenched from the draw temperature of 1148°F. (620°C.). They could find no evidence of tin under the microscope. Whitely and Braithwaite3 investigated the effect of tin on rail steel containing 0.55 to 0.60 per cent carbon. They found that 0.08 per cent tin caused a marked decrease in elongation, notched impact resistance and the degree of bend. The tensile strength was increased in some tests and not in others. Bolsover and Barraclough4 investigated the effect of tin up to 0.50 per cent on a 0.35 per cent carbon steel and on several alloy steels with from 0.30 to 0.40 per cent carbon. They found a comparatively uniform decrease in notched impact resistance with increasing tin on quenched and drawn samples. If the samples were quenched from the drawing temperature or reheated to the drawing temperature and quenched, the embrittling was much less severe. Steels containing molybdenum suffered much less embrittlement than other steels. EXPERIMENTAL WORK Effect of Tin on Low-carbon Rimmed Steel Increasing quantities of tin were added to four ingots of a heat of the following ladle analysis: carbon, 0.08 per cent; manganese, 0.39; phosphorus, 0.009; sulphur, 0.025.

Jan 1, 1942

By J.W. Halley

The effects of tin on steel have become increasingly important because of the necessity of using poorly detinned scrap, tin cans, and terne plate, in the open hearth. Since a tin can contains about 1.5 per cent tin, it would be possible to have up to 0.75 per cent tin in steel made with a 50 per cent scrap charge. In order to use tin-containing scrap, it is necessary to know the effect of tin on various grades of steel. The following investigation is by no means comprehensive but covers a number of steels in which tin content is important. Published Work A number of investigations of the effects of tin on rolling quality and physical properties have been published. It has been found that tin increases strength and hardness and reduces ductility and notched impact resistance. The decrease' in ductility and notched impact resistance becomes more marked as the carbon decreases. McKimml found no change in Olsen ductility, Kockwell hardness, yield strength, tensile strength or elongation in cold-reduced strip containing up to 0.124 per cent tin. A tin content of 0.1j per cent gave difficulties in rolling and increased the hardness but 0.21 per cent tin showed no change in properties from material containing very little tin. No explanation of this contradiction is offered. Andrew and Peile2 investigated steels containing 0.10 to 0.25 per cent carbon and up to 0.63 per cent tin. They found an increase in tensile strength of from 100 to 200 lb. per sq. in. for each 0.01 per cent tin on normalized samples. The elongation and reduction of area were decreased and the notched impact resistance was reduced markedly. Quenched and drawn samples did not show embrittling if water-quenched from the draw temperature of 1148°F. (620°C.). They could find no evidence of tin under the microscope. Whitely and Braithwaite3 investigated the effect of tin on rail steel containing 0.55 to 0.60 per cent carbon. They found that 0.08 per cent tin caused a marked decrease in elongation, notched impact resistance and the degree of bend. The tensile strength was increased in some tests and not in others. Bolsover and Barraclough4 investigated the effect of tin up to 0. 50 per cent on a 0.35 per cent carbon steel and on several alloy steels with from 0.30 to 0.40 per cent carbon. They found a comparatively uniform decrease in notched impact resistance with increasing tin on quenched and drawn samples. If the samples were quenched from the drawing temperature or reheated to the drawing temperature and quenched, the embrittling was much less severe. Steels containing molybdenum suffered much less embrittlement than other steels. Experimental WoRk Effect of Tin on Low-carbon Rimmed Steel Increasing quantities of tin were added to four ingots of a heat of the following ladle analysis: carbon, 0.08 per cent; manganese, 0.39; phosphorus, 0.009; sulphur, 0.025.

Jan 1, 1943

By J. W. Halley

The effects of tin on steel have become increasingly important because of the necessity of using poorly detinned scrap, tin cans, and terne plate, in the open hearth. Since a tin can contains about 1.5 per cent tin, it would be possible to have up to 0.75 per cent tin in steel made with a 50 per cent scrap charge. In order to use tin-containing scrap, it is necessary to know the effect of tin on various grades of steel. The following investigation is by no means comprehensive but covers a number of steels in which tin content is important. Published Work A number of investigations of the effects of tin on rolling quality and physical properties have been published. It has been found that tin increases strength and hardness and reduces ductility and notched impact resistance. The decrease' in ductility and notched impact resistance becomes more marked as the carbon decreases. McKimml found no change in Olsen ductility, Kockwell hardness, yield strength, tensile strength or elongation in cold-reduced strip containing up to 0.124 per cent tin. A tin content of 0.1j per cent gave difficulties in rolling and increased the hardness but 0.21 per cent tin showed no change in properties from material containing very little tin. No explanation of this contradiction is offered. Andrew and Peile2 investigated steels containing 0.10 to 0.25 per cent carbon and up to 0.63 per cent tin. They found an increase in tensile strength of from 100 to 200 lb. per sq. in. for each 0.01 per cent tin on normalized samples. The elongation and reduction of area were decreased and the notched impact resistance was reduced markedly. Quenched and drawn samples did not show embrittling if water-quenched from the draw temperature of 1148°F. (620°C.). They could find no evidence of tin under the microscope. Whitely and Braithwaite3 investigated the effect of tin on rail steel containing 0.55 to 0.60 per cent carbon. They found that 0.08 per cent tin caused a marked decrease in elongation, notched impact resistance and the degree of bend. The tensile strength was increased in some tests and not in others. Bolsover and Barraclough4 investigated the effect of tin up to 0. 50 per cent on a 0.35 per cent carbon steel and on several alloy steels with from 0.30 to 0.40 per cent carbon. They found a comparatively uniform decrease in notched impact resistance with increasing tin on quenched and drawn samples. If the samples were quenched from the drawing temperature or reheated to the drawing temperature and quenched, the embrittling was much less severe. Steels containing molybdenum suffered much less embrittlement than other steels. Experimental WoRk Effect of Tin on Low-carbon Rimmed Steel Increasing quantities of tin were added to four ingots of a heat of the following ladle analysis: carbon, 0.08 per cent; manganese, 0.39; phosphorus, 0.009; sulphur, 0.025.

Jan 1, 1943

By H. T. Clark

NO previous determinations of the deformation or recrystallization textures of titanium or of titanium-base alloys have been reported in the literature. The room-temperature structure of titanium is hexagonal close-packed with a c/a ratio less than 1.633. It would be expected, therefore, to have a rolling texture similar to that of other hexagonal close-packed metals, namely (0001) [1010]. Burgers and Jacobs1 have shown that zirconium, a metal isomorphous with titanium in its structure and similar in many of its properties, has such a texture with a scatter of the basal plane toward the transverse direction. This scatter is in the opposite direction from that found in magnesium by Bakarian2 but similar to that reported by Smigelskas and Barrett3 or beryllium. The rolling and annealing textures reported here for high-purity iodide titanium are significantly different from the . textures of any other hexagonal close-packed metal. All titanium used during this investigation was prepared by the iodode process." The annealed hardness of this material varied from 73 (material used for sample No. 2) to 97 Vickers hardness number. An estimate of the chemical composition of this grade of titanium has been reported by Finlay and Snyder.5 With one exception, shown in table I, the as-deposited titanium was cast into 10 to 20 g ingots in an electric arc furnace in purified argon before being rolled to sheet. The cast ingots were forged and ground until their cross-section was approximately rectangular, annealed 1 hr at 700°C in vacuum and cold rolled. Rolling was carried out in a two-high, 4 in. diam mill, using reductions no greater than 10 pct per pass. The direction of rolling was reversed after each pass, and, in order to avoid temperature effects, the sheet was allowed to cool after each pass. Unless the rolled sheet was sufficiently thin for X-ray penetration (about 0.004 in.), it was reduced to this thickness by pickling. Because of the possibility of introducing twinning or other deformation during grinding, no attempt was made to maintain uniform thickness of the sample during pickling by intermediate grinding or sanding operations. Those samples to be used for determining the annealed texture were recrystallized by vacuum annealing the cold-rolled sheet for 1 hr at 500°C. These thin samples were held between thick titanium sheets during annealing to prevent distortion. Table I outlines the rolling and annealing schedule of those samples for which photograms or texture patterns are shown. X-ray Techniques The usual techniques for determining textures were employed during this work. Molybdenum radiation was used for the transmission exposures and copper radiation for the glancing angle ones. Since titanium fluoresces under these conditions, it is necessary to employ a filter between the sample and the film. The Kß radiation filters are very satisfactory for this purpose. Sufficient grains having favorable orientation were present in both the cold-worked and in the cold-worked—500°C annealed samples to provide satisfactory patterns with the samples stationary. Because of the difficulties of comparing intensities of transmission photograms with those obtained

Jan 1, 1951

By John S. Johnson

The purpose of this article is to describe several types of borehole lining in common use, and especially to offer a relatively new means of reducing the expense of maintaining boreholes where they are subjected to corrosive action of water flowing either inside or outside of their casing. In the Anthracite region of Pennsylvania, boreholes are used for many purposes, the principal ones being: openings between the surface and underground workings through which are passed steam, water and compressed-air lines, ropeways from surface hoists to underground rope haulages, conduits for electric power and signal lines, water-discharge lines from underground pumping stations, and inlets to mine workings for flushing material. Linings for Boreholes The inadequacy of steel pipe for use in boreholes has long been recognized. Various substitute materials have been tried, including screw-joint cast-iron pipe (Fig. I). Cast-iron pipe, while very effective as a discharge line for acid water (mine water) being pumped to the surface, is not so effective when serving as a conduit for silt and crushed rock being flushed underground for filling mine voids. Terra cotta pipe (Fig. 2) has been used in boreholes, and lasts a long time if the glazed inner surface of the pipe remains intact. Its installation in a borehole is very difficult and is recommended only where it is certain that there will be no subsidence of the surrounding territory. Accessibility in order properly to join each section of the pipe is essential to a satisfactory job. In large water holes, where it is possible to lower a man into the hole for sealing the joints of the pipe, glazed terra cotta pipe has been used successfully for delivering mine water from pumps in the mines. For large holes used for flushing refuse into mine workings where the surface wash is shallow, standard paving brick have been used to form a tube through the wash to the bedrock. These brick are laid radially, backed by common brick and cobbles laid in cement. It is obvious that the shaft through the wash must be large enough to permit a man to work in it. The flushing material is carried through bare rock from the juncture at bedrock to the openings underground. This plan has been used particularly where a cast-iron surface line is laid upon the surface to carry the flushing material from the breaker to the hole, and down the hole continuously, with no opening to the air at the top of the hole, thereby eliminating the necessity of an attendant at this point (Fig. 3). Another similar type of borehole lining is constructed of hexagonal pieces of vitrified brick (Fig. 4). This type requires a steel drive pipe through the surface wash large enough to provide a finished tube of the desired size surrounded by a brick wall about 4 in. thick. The special bricks are laid in cement, six to a circle, around a lubricated pipe used as a form, and lowered in sections inside the large drive pipe; the bottom section is seated in a socket drilled in the solid rock, having the same inside

Jan 1, 1942

By John S. Johnson

The purpose of this article is to describe several types of borehole lining in common use, and especially to offer a relatively new means of reducing the expense of maintaining boreholes where they are subjected to corrosive action of water flowing either inside or outside of their casing. In the Anthracite region of Pennsylvania, boreholes are used for many purposes, the principal ones being: openings between the surface and underground workings through which are passed steam, water and compressed-air lines, ropeways from surface hoists to underground rope haulages, conduits for electric power and signal lines, water-discharge lines from underground pumping stations, and inlets to mine workings for flushing material. Linings for Boreholes The inadequacy of steel pipe for use in boreholes has long been recognized. Various substitute materials have been tried, including screw-joint cast-iron pipe (Fig. I). Cast-iron pipe, while very effective as a discharge line for acid water (mine water) being pumped to the surface, is not so effective when serving as a conduit for silt and crushed rock being flushed underground for filling mine voids. Terra cotta pipe (Fig. 2) has been used in boreholes, and lasts a long time if the glazed inner surface of the pipe remains intact. Its installation in a borehole is very difficult and is recommended only where it is certain that there will be no subsidence of the surrounding territory. Accessibility in order properly to join each section of the pipe is essential to a satisfactory job. In large water holes, where it is possible to lower a man into the hole for sealing the joints of the pipe, glazed terra cotta pipe has been used successfully for delivering mine water from pumps in the mines. For large holes used for flushing refuse into mine workings where the surface wash is shallow, standard paving brick have been used to form a tube through the wash to the bedrock. These brick are laid radially, backed by common brick and cobbles laid in cement. It is obvious that the shaft through the wash must be large enough to permit a man to work in it. The flushing material is carried through bare rock from the juncture at bedrock to the openings underground. This plan has been used particularly where a cast-iron surface line is laid upon the surface to carry the flushing material from the breaker to the hole, and down the hole continuously, with no opening to the air at the top of the hole, thereby eliminating the necessity of an attendant at this point (Fig. 3). Another similar type of borehole lining is constructed of hexagonal pieces of vitrified brick (Fig. 4). This type requires a steel drive pipe through the surface wash large enough to provide a finished tube of the desired size surrounded by a brick wall about 4 in. thick. The special bricks are laid in cement, six to a circle, around a lubricated pipe used as a form, and lowered in sections inside the large drive pipe; the bottom section is seated in a socket drilled in the solid rock, having the same inside

Jan 1, 1942

By Nicholas J. Grant, David S. Bloom

An investigation of the Cr-Ni system has revealed that there exists a eutectoid transformation at about 1180°C. 'The transformation in chromium implied by the eutectoid reaction was detected at about 100°C below its melting point. Associated with the eutectoid transformation, a metastable transition structure has been found. THE Cr-Ni phase diagram is shown in current literature to be a simple eutectic system in which the high chromium end of the diagram is incompletely determined, Fig. 1. The last investigation of this system was undertaken in 1936.' Because of limitations in metal purity, especially of chromium, and temperature measuring techniques, the diagram should be accepted with some reservations, as was indicated by Hansen.V or examwle.-, the wresence of the compound Cr²Ni, with a tetragonal structure," remains unverified and incompatible with the simple eutectic diagram. The work reported here began because of discrepancies that appeared in experimental studies in the binary alloys Cr-Ni and in the ternary system Cr-Mo-Ni. The existing binary Cr-Ni diagram failed to provide a complete explanation of observations made by microscope, X-ray, and thermal analyses. Experimental Methods The materials employed were of a higher degree of purity than were available to previous investigators. The Mond nickel used had a nominal purity of 99.87 pct, while the electrolytic chromium analyzed 99.03 pct with the major impurity being 0.5 to 0.7 pct oxygen with some iron. All alloys were melted in a vacuum furnace to remove dissolved gases, sufficient carbon was added to the charge to combine with all the oxygen as CO. Final analysis determined the carbon as about 0.02 pct and the oxygen around 0.06 pct or slightly more. Stabilized zirconia crucibles and thermocouple protection tips were used throughout and contributed no detectable impurity to the melts, as long as the oxygen in the chromium was kept low. Heats averaged about 250 g, which permitted about 2 in. of the thermocouple protection tips to be submerged. The temperature drop across the thermocouple protection tip was determined to be about 3°C, a minor source of error. The alloys, after removal from the vacuum furnace, were placed in a furnace operating in a purified argon atmosphere for the thermal analyses. An- nealed wolfram-molybdenum thermocouples provided the primary means of temperature determination, though a Pt-Pt-10 pct Rh couple was employed for a check when possible. A sensitive, high-speed Leeds and Northrup Speedomax recording potentiometer indicated the thermocouple output. X-ray diffraction patterns were obtained primarily on a Norelco unit, which permitted diffraction angles only up to 45" (28 = 90"). In general, either rotated or stationary solid samples were used, because it later evolved that many samples were susceptible to transformation resulting from the cold working involved in pulverizing. It was also noted that rotating a sample sometimes suppressed weak lines, so, usually, samples were not rotated. Later a high temperature camera was adapted for use at temperatures up to 1400 °C on the Norelco unit utilizing both solid and powdered samples. Unless otherwise noted, all X-ray patterns were made with a chromium tube and a vanadium filter. Further-

Jan 1, 1952

By John S. Johnson

THE purpose of this article is to describe several types of borehole lining in common use, and especially to offer a relatively new means of reducing the expense of maintaining boreholes where they are subjected to corrosive action of water flowing either inside or outside of their casing. In the Anthracite region of Pennsylvania, boreholes are used for many purposes, the principal ones being: openings between the surface and underground workings through which are passed steam, water and compressed-air lines, ropeways from surface hoists to underground rope haulages, conduits for electric power and signal lines, water-discharge lines from underground pumping stations, and inlets to mine workings for flushing material. LININGS FOR BOREHOLES The inadequacy of steel pipe for use in boreholes has long been recognized. Various substitute materials have been tried, including screw-joint cast-iron pipe (Fig. I). Cast-iron pipe, while very effective as a discharge line for acid water (mine water) being pumped to the surface, is not so effective when serving as a conduit for silt and crushed rock being flushed underground for filling mine voids. Terra cotta pipe (Fig. 2) has been used in boreholes, and lasts a long time if the glazed inner surface of the pipe remains intact. Its installation in a borehole is very difficult and is recommended only where it is certain that there will be no subsidence of the surrounding territory. Accessibility in order properly to join each section of the pipe is essential to a satisfactory job. In large water holes, where it is possible to lower a man into the hole for sealing the joints of the pipe, glazed terra cotta pipe has been used successfully for delivering mine water from pumps in the mines. For large holes used for flushing refuse into mine workings where the surface wash is shallow, standard paving brick have been used to form a tube through the wash to the bedrock. These brick are laid radially, backed by common brick and cobbles laid in cement. It is obvious that the shaft through the wash must be large enough to permit a man to work in it. The flushing material is carried through bare rock from the juncture at bedrock to the openings underground. This plan has been used, particularly where a cast-iron surface line is laid upon the surface to carry the flushing material from the breaker to the hole, and down the hole continuously, with no opening to the air at the top of the hole, thereby eliminating the necessity of an attendant at this point (Fig. 3). Another similar type of borehole lining is constructed of hexagonal pieces of vitrified brick (Fig. 4). This type requires a steel drive pipe through the surface wash large enough to provide a finished tube of the desired size surrounded by a brick wall about 4 in. thick. The special bricks are laid in cement, six to a circle, around a lubricated pipe used as a form, and lowered in sections inside the large drive pipe; the bottom section is seated in a socket drilled in the solid rock, having the same inside

Jan 1, 1941

After the explosion in the Black Heath pit, that company sent to England for some experienced miners to reopen the mine. The results of their work in this vicinity are mentioned in an advertisement for pit hands by the Mid-Lothian Co., as follows: "PIT HANDS WANTED.-In consequence of reports having been circulated of the insecurity of hirelings in the Mid-Lothian Mines, the Company deem it proper to make known, that the mines have recently been opened, and that not the slightest explosion from gas has occurred; the workings were laid out and are now progressing, ° under a plan furnished by Messieurs Foster & Hall, .two distinguished English Colliers, sent over from England to reclaim the Pits of the Black Heath Company after the recent explosion of gas-and the present under ground operations are now conducted under the management of one of the English foremen left here by these gentlemen, and supervised by Mr. Wm. Hall, who has under his superintendence the Black Heath Company's Works at present. The skill and capacity of those gentlemen, is fully evinced in their skilful reclamation of the Black Heath Mines, and their present successful working of said Pits; and their confidence in the safety of the hands in the Mid-Lothian Mines, will be seen, by reference to the annexed extract from the Plan left by Messrs. Foster & Hall for laying out and working the Mid-Lothian Mines, and from the Certificate of Mr. William Hall, as to the manner in which that plan is carried into effect. This publication has been deemed proper, as the Company are now in want of some ten or fifteen additional able-bodied, active Pit-hands, on hire by the year, for which they will give the most liberal hire. The Company have not hitherto spared any labor or expense, deemed necessary to secure the absolute safety and comfort of the hands in their mines; nor is it designed in future to omit any thing that can add to the security of their own hands, or the hired laborers of other persons-indeed they can, with great propriety, say, as far as they have progressed, that no mines in this country exhibit stronger, if as strong, evidence of general safety. The Company will receive on hire, no hands who do not voluntarily enter their service -and they request of those having hands to hire out, to remember that they will want upon hire, successively, at intervals of every ninety days, some additional four or five hirelings during the year, or to purchase, progressively, that number of healthy, able-bodied young men. "Owners of slaves at a distance from the Coal Mines, would do well to give some attention to the subject. There is no place in this country where slave labor commands as much, where their general health is better, and where the treatment and contentment of the slaves are surpassed. It is true that within the last few years several disastrous accidents have occurred, but from the scientific and practical skill attracted to the mines, these accidents will be of rare occurrence, it is to be hoped. A. S. WOOLDRIDGE, President, at the Mines in Chesterfield County.

Jan 1, 1942

By N. F. Foster

The use of piezoelectric semiconducting materials for the fahrication of ultrasonic transducers has raised the upper fundamental frequency limit for transducers from about 200 mc to above 10 kmc, Several types of semiconductor transducer configurations have been proposed and examined experimentally. Depletion-layer transducers have been made and operated at frequencies below 1 kmc hut they appear to he better suited for operation at considerably higher frequencies around 10 knzc. Diffusion-layer transducers have been made and operated in the range 50 to 1000 mc and have exhihited considerably improved conversion losses and bandwidths compared with other transducers available in the frequency range. A variety of novel structures are possible using these new types of transducers, some of which could lead to substantial advances both in research and in the fabrication of ultrasonic delay lines and memory elements. THE field of ultrasonics today spans some five decades of the frequency spectrum from the audible to the kmc range and finds applications ranging from fundamental research into the atomic structure of matter to the degreasing of machine parts. To cover this wide range it has been necessary to develop a great many types of ultrasonic trandsucers utilizing a variety of materials and physical phenomena. The first ultrasonic transducers were made during World War I for a submarine-detection system. They consisted of plates of single-crystal quartz bonded between metal plates and were one of the first applications of the phenomenon of piezoelectricity discovered nearly 30 years previously. Despite the many advances which have been made in transducer technology, piezoelectric transducers using single-crystal quartz are still used almost exclusively for application above about 30 mc. Transducers at these frequencies are normally made in the form of thin quartz plates which are then bonded onto the medium in which the ultrasonic wave is to be propagated. The crystallographic orientation and geometry of these plates determines the type of wave generated and the way in which the efficiency of the electromechanical conversion varies with frequency. Analysis of the design parameters shows1 that the frequency of maximum efficiency (the fundamental or resonant frequency) is that frequency at which the transducer is approximately half the wavelength of the ultrasonic wave in the material. As the frequency increases, the ultrasonic wavelength, and therefore the optimum transducer thickness, decreases and in practice the fabrication of quartz transducers with fundamental freauencies above 100 mc becomes extremely difficult due to the extreme thinness required. For frequencies above 100 mc quartz transducers can be used in overtone-mode operation, and for very high frequencies (500 to 24,000 me) a technique using a quartz rod inserted in a high-Q microwave cavity4 is available. These techniques, however, exhibit comparatively low fractional bandwidths and rather poor conversion efficiencies. The present trend in ultrasonics is towards high frequencies and greater bandwidth to allow the use of shorter pulses which can give increased discrimination in radar-system delay lines and greater storage capacity in computer applications. The increasing demand for more efficient transducers with greater bandwidth

Jan 1, 1964

By T. F. McCormick

THIS year, 1950, is the golden anniversary of the construction and operation in this country of a tube mill for the sole purpose of fabricating aluminum alloy tubing. For a short period prior to the beginning of this mill, aluminum alloy tubing was obtained from foreign sources or produced in mills fabricating other metals. Indeed, it was a very short period because aluminum itself was a newcomer in the field of metals. The first sheet rolling mill had been in operation just eight years and a rod rolling mill for the production of wire and cable had been functioning one year. The first tube mill for aluminum was built by the Aluminum Co. of America in May 1900 and started production with four draw benches and five men, including the mill superintendent. The building itself was a lean-to attached to a sheet-rolling mill at New Kensington, Pa. The cost of equipment, including the draw benches, dies, mandrels, and other tools, was about $5000. This figure seems absurd in the present day but nevertheless it was questioned at that time whether or not such a large sum should be spent to embark on a new and uncertain venture. The initial production system for the new mill consisted of casting round hollow ingots in a tilting-type iron mold, reducing the ingots to bloom size outside the plant, and finally drawing to size on the draw benches. This method of producing aluminum alloy tubing survived just two years, as blooms of satisfactory quality were not obtained consistently. It was superseded by the cupping method in which a 24-in. diam circle cut from a rolled plate was formed into a tube bloom using first a small cupping press and then a push bench. It was stated that tubing so produced was limited to a maximum diameter of 2 3/4 in. and to wall thicknesses varying from 12 to 24 gage. However, for the first time all the operations were performed at one plant and the result was a quality product. Later larger cupping presses and push benches were obtained and the method continued to be the principal one for aluminum alloy tubing for almost a quarter of a century. During the interim the use of a Alan Mannesmann -type billet piercer was explored and it was used to some extent, but failed to produce consistently a smooth inside surface suitable for drawing with aluminum alloys. Experiments started during the latter stages of World War I in the production of tube blooms with a hydraulic extrusion press, led to the use of this type of equipment to make tube blooms for further drawing during a change-over period extending from 1925 until 1930. At this time the cupping method was discarded completely. From these humble beginnings, the aluminum alloy tubing business expanded until well over six million pounds were produced in a single month in the United States during World War II. The major portion of this production was in strong alloys which did not appear in the tubing picture until 1022, when 17S alloy tubing was introduced for aircraft construction.

Jan 1, 1951

By K. E. Manchester, C. B. Sibley

The feasibility of doping silicon to produce device structres by directly implanting impurity atoms has been demonstrated. Both phosphors and boron ions have been successfully implanted in silicon to produce electrical junctions. Junctions as deep as 1.2 p have been produced by phosphorus ions having energies the order of 80 kev. An electromagnetic separator has been used to controllably produce uniform, large-area implantations for evaluation experimentation. Correlations between junclion depths and ion energies huve been obtained. Orientation effects have been observed and it has been found that the (110) direction is the easy direction for implanting. Monitoring of thermal treatments oj implanted substrates by sheet-resistance measurement indicates a very mild thermal anneal removes most of the damage done during the implantation. These indications are further substantiated by reverse-current measurements of j,inctions Produced by implantation. Electrical characteristics of implanted junctions are compared with those of diffused junctions. We have been interi n the interaction of energetic ions in the III-V groups, in particular boron and phosphorus, with single-crystal silicon to produce type conversion for possible device use. A number of investigators, a few of whom are avies, Kornelson,3 and so forth, have reported on penetration of energetic ions into both amorphous and crystalline solids. While most work has been done with ions of the rare gas and alkali metal groups, some work has been reported by ing, erber,' and others6 in which ions of the 111-V groups have been implanted in single-crystal silicon. A large amount of this work has been done with ion energies in the 100-kev to 1.5-Mev range. An excellent review article has been written by caldin. We have concentrated on ion energies which are in the 10 to 80 kev range, with which over 1500 implanted junctions such as the one shown in Fig. 1 have been produced in silicon substrates with both phosphorus and boron ions. Fig. 1 is a 3-deg angle lap in which the n type area produced by 66 kev P is delineated and the junction is 9500A below the surface. EXPERIMENTAL Implantations reported in this paper were made with the ion source adjusted to produce ion currents in the range of 1 to 2 pa with accelerating voltages varied from 10 to 40 kv. When using doubly charged ions this produced 10 to 80 kev ions. This allowed substrate temperatures to remain below 100°C. Sam- ple movement resulted in beam impingement angle variation of 7 deg from the normal to the substrate surface. Substrate resistivities have been varied through the range of 0.001 to 500 ohm-cm and specimens oriented in three directions, (110), (Ill), and (loo), within 12 deg. RESULTS For the purpose of this paper, discussion of results will be limited to phosphorus implantations with mention of results for boron-implanted silicon. Similar results have been obtained for boron and will be reported at a later date. In Figs. 2, 3, and 4 depth penetration is shown

Jan 1, 1967

By Leo Tarasov

MAGNETIC torque studies of ferromagnetic single crystals have been carried out in a number of laboratories during the last decade1,2 and some work has been reported on polycrystalline material showing preferred orientation. Goss3 used the method extensively in developing electrical sheet with desirable magnetic properties, but he used it as a control rather than as a means of studying the texture. Bozorth4 made a quantitative correlation of a torque curve he obtained from some cold-rolled iron with the texture as determined from X-rays, but did not extend his studies beyond the one specimen. Other studies, which have been reported from time to time 1.5 have also been incomplete in the sense that no effort was made to study a whole series of samples, differing only in degree of cold reduction, or in the annealing temperature, in order to ascertain the effect of such treatments on the texture as revealed by torque measurements. It is the purpose of this investigation to make such a study, mainly in order to see how useful the method can be made when used under favorable circumstances and to find what kind of a correlation can be expected between magnetic and X-ray studies of texture. Before proceeding further, it is desirable to say a little about single crystals, so as to make clear the concepts involved in magnetic torque measurements.

Jan 1, 1939

By Richard H. Rein, John Chipman

Liquid slags of the system SiO2-Ca0-MgO-A1~03 were equilibrated with liquid Fe-Si-C alloys in graphite or Sic crucibles at 1600°C in pure CO gas at atmospheric pressure, and the silicon content of both phases determined. Ternary slugs of the systern SiO2-CaO-A12O3 were also studied at 1550°C. The silicon content of the metal phase saturated with both graphite and SIC is 22.0pct at 1550°C and In the iron blast furnace, as in nearly all carbon-reduction processes, some silicon is transferred from slag to metal. The importance of this reaction is enhanced by its indirect effect on the transfer of sulfur from metal to slag, and this has stimulated a comprehensive research program on the equilibrium distribution of silicon between slag and metal. Earlier studies'-3 of this same problem provided data for calculation of the thermodynamic activities4 of the components in SiO,-CaO-A1,O3 slags. 22.4 pct at 1600°C. The temperature at which the phases cristobalite, gvaphite, $ SiC, liquid slag, Fe-Si-C alloy, and CO gas at 1 atm pressure can coexist in equilibrium was found to be 1533°C. The results agree well with earlier studies. They are shown graphically as lines of constant silicon cmtent in the metal which also are lines of constant SiO, activity in the slag.

Jan 1, 1963

The Johns Hopkins Press, Johns Hopkins University, Baltimore, Md The Johns Hopkins Press has issued a number of books as The Johns Hopkins University Studies in Geology Five of the studies are paleontological in character; five are on geology: No. 1, The geology of the Corocoro copper district of Bolivia, by J. T Singewald, Jr and E W. Berry, $1 50, 2, The geology and paleontology of the Huancavehca mercury district, by E W Berry and J T Singewald, Jr $1 50, 6, Contributions to the geology and paleontology of South America, by E W. Berry and F M Swartz, 3175, 7, The geology of the Island of Trinidad, B W I, by G A Waring, with notes on the paleontology by G. D Harris, $1 75, 8, Fifty years' progress in geology, 1876-1926 Papers presented at the Geological Conference during the 50th Anniversary of the Johns Hopkins University, $1 50 An additional publication on geology is. Notes on the minerals occurring in the neighborhood of Baltimore, by G H Williams, 25 cents. In the list of Doctors' Dissertations available from the University are found all theses on geology and mineralogy, about 90 in number, from 1886 on Authors of many of these have since made great names for themselves in the fields of geology and mineralogy. Most of the theses have been published as papers by other agencies and, as such, will be found under other headings in this directory

Jan 1, 1933

By Gail F. Moulton

In spite of an increase of 7 cents per barrel in the posted price of oil for the Panhandle field effective June 16, 1943, there was less drilling during 1943 than ir, any of the several previous years. The drilling statistics are compiled as Table 2 and show the material increase in the percentage of the total number of field wells completed as dry holes. This increase suggests that the productive area of the field is largely drilled up on the well-spacing pattern now followed and that new discoveries will be required to permit any important new activity in the area. The fact that only four wildcats were drilled in the area during the year indicates that some new prospecting technique or some ncw point of view is required to stimulate exploration. No new producing areas were discovered during 1943 and no additions to oil reserves were made through extensions or discovery 'of new pays. Accordingly, the proven reserves in the area declined by the amount of the production, or nearly 31 million barrels. These results of drilling are similar to those obtained during 1942, whcn no new oil areas were discovered as a result of wild-catting, a total of five wildcat wells in 1942 resulting in four failures and one gas-fieid discovery of undetermined merit. sion. The number of oil-producing wells reported by the Commission increased during the year by 163 to a total of 5576 as of December.

Jan 1, 1944

By Gail F. Moulton

In spite of an increase of 7 cents per barrel in the posted price of oil for the Panhandle field effective June 16, 1943, there was less drilling during 1943 than ir, any of the several previous years. The drilling statistics are compiled as Table 2 and show the material increase in the percentage of the total number of field wells completed as dry holes. This increase suggests that the productive area of the field is largely drilled up on the well-spacing pattern now followed and that new discoveries will be required to permit any important new activity in the area. The fact that only four wildcats were drilled in the area during the year indicates that some new prospecting technique or some ncw point of view is required to stimulate exploration. No new producing areas were discovered during 1943 and no additions to oil reserves were made through extensions or discovery 'of new pays. Accordingly, the proven reserves in the area declined by the amount of the production, or nearly 31 million barrels. These results of drilling are similar to those obtained during 1942, whcn no new oil areas were discovered as a result of wild-catting, a total of five wildcat wells in 1942 resulting in four failures and one gas-fieid discovery of undetermined merit. sion. The number of oil-producing wells reported by the Commission increased during the year by 163 to a total of 5576 as of December.

Jan 1, 1944

By Greenleaf W. Pickard

The Parral mining district is located in the southern part of the state of Chihuahua in north-central Mexico, in the border area of the physiographic provinces of the Mesa Central and the Sierra Madre Occidental, at an average elevation of 1700 meters. This is one of the most highly productive lead-zinc districts of Mexico. The principal operating units are the Prieta, Santa Barbara and San Francisco mines. The Santa Barbara-San Francisco del Oro area is located 25 kilometers to the southwest of the Prieta mine. It has a system of generally narrow veins in fault zones, entirely in the shale series. The Santa Barbara veins follow long, persistent fractures, while the San Francisco del Oro veins are in relatively short fractures. The Veta Colorada structure, located 5 kilometers to the northwest of the Prieta mine, was a major producer of high grade silver ore with low lead-zinc content during the eary 1900's. It follows a major north-south fault zone in andesite and is noteworthy for a number of wide oreshoots of limited vertical extension along its 10 kilometer length. The Palmilla and Esmeralda mines are on the south end of the Veta Colorada structure. Numerous smaller mines are operating in the Parral area. During the last 45 years the Prieta mine has produced approximately 15,000,000 tons of complex sulfide ore, principally from one single vein. Extensive stoping has

Jan 1, 1970

By E. T. Dumble

DuriKg explorations made for the Pacific Improvement Company in the early part of this year, deposits of natural coke, of such extent and excellent quality as to be worthy of record, were found in the Santa Clara coal-field. This coal-field lies in the neighborhood of La Barranca, a small town, 95 miles northeast of Ortiz, on the Sonora railway. The coal-beds are exposed in the drainage-basin of Calera creek, which empties into the Yaqui river opposite Toniche; and the old mining town of Turahumari is nearly at the center of the field. Without going into a detailed geological description, it Will be sufficient to say that the entire area is underlain by rocks of Triassic age, much disturbed in places, and cut through and covered by eruptive rocks of various kinds and ages. The coal-beds occur in a series of interbedded sands and clay, in the upper half of the sedimentary Triassic rocks. Below them is a great series of quartzitic sandstoiles and very sandy slates, and above them are other sandstones, and the eruptive member of the group, viz., the Lista Blanca formation', described in my paper on the " Geology of Sonora," presented at the New York Meeting of February, 1899.* Speaking very broadly, these sands and clays, with their included coal-beds, dip about 30 degrees S.E. This gives their outcropping edses a 3J.E.-S.W. direction. The general dip

Jan 1, 1900

By Robert Lindsay

A NUMBER of detailed investigations of the physical changes accom-panying age-hardening have raised the question as to the possibility of some phenomenon preceding the actual process of precipitation. There is considerable evidence to indicate that in the first stages of the aging process there is a pronounced distortion of the crystal lattice. This is particularly marked in duralumin. It would be of considerable theo-retical interest to know the nature of this distortion as compared with that produced in other ways and to find out whether, in supersaturated alloys, it is a necessary antecedent to the formation of a second phase by precipitation. It was believed that a study of the age-hardening char-acteristics of a normally aged alloy compared with one that had been mechanically distorted might supply some useful information on these points. In addition, information would be obtained regarding the effect of a mechanical distortion on any subsequent stage in the aging process. Duralumin was chosen as the material for this investigation because the various aspects of its aging behavior can be shown in detail by suit-able variations of the aging temperature. Also, probably more work has been done on this class of alloys than on any other. In spite of the many published results, it was felt that the experiments would be significant only if all of the work were done on samples from the same source and if they were examined under identical experimental conditions.

Jan 1, 1939