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By R. T. Southin

Cast ingots of 99.99 pct purity A1 and aluminum/copper alloys containing up to 2 pct Cu have been found to contain four zones rather than the three previously accepted, i.e., chill, colummar, and equiaxed zones. The fourth zone consists of a coarse dendritic layer across the top surface of the ingot which is open to the atmosphere. It is also found that the grains in the equiaxed region have a "cornet" shape, with a head which is coarsely dendritic and a tail which grew with the same structure as the columnar grains. Experiments using mechanical barriers, and others involving the elimination of the surface dendrile layer, have indicated that nucleation of the equiaxed zone is caused by the showering of dendritic particles from this surface dendrite layer. These particles are the dendritic heads found in the comet grains. A mechanism of nucleation and growth of these comet grains is put forward. Experiments with a number of other metals and alloys suggests that these conclusions may apply generally to ingots cast without the addition of nucleating agents, and solidified under normal conditions. THE macrostructure of cast ingots may contain the following three zones: i) a peripheral zone of fine equiaxed grains, commonly called the chill zone; ii) a zone of columnar grains extending inwards from the chill zone; iii) a central zone of equiaxed grains; these are normally larger than the chill grains. All three zones are not necessarily present in any particular ingot since their existence and magnitude depend upon the casting conditions and composition of the cast material. The mode of formation of zones i and ii is fairly well understood. However, the cause of the central equiaxed zone remains a matter of conjecture. Previous theories put forward to explain the mechanism of nucleation in the equiaxed zone have been examined by Chalmers1 and Winegard.2 At the time when the present work was carried out the most re -cent hypothesis was that due to Chalmers,1 who recognized more fully than previous workers that conditions in this zone during solidification were not conducive to nucleation. In his hypothesis, he suggested that nuclei were formed near the mould wall during the very early stages of solidification, and that they can drift into the central zone by convective motion. This was supported by evidence from experiments using mechanical barriers to stop the drift of nuclei. A similar hypothesis had previously been put forward by Genders.3 More recently, Jackson et al. 4 have observed that dendrite arms in organic compounds can melt off during solidification. They have postulated that this occurs in metals and alloys, and that the dendrite arms which have been freed from the main dendrite act as nuclei for the equiaxed zone. In the present work, critical metallographic examination has shown that there is a fourth zone in the macrostructure of cast ingots which is a dendritic layer over the top surface of the ingot. It is also shown that there is a relationship between this zone and nucleation of the equiaxed zone. EXPERIMENTAL DETAILS The alloys examined were prepared from super -purity aluminum of 99.99 pct min purity (spectro-graphically detected impurities of Cu, Fe, Si, and Mg) and copper of 99.98 pct min purity (spectrographically detected impurities of Si, Zn, As, Fe, Pb, Bi, Ni, Sn, Mn, Ag, Cr, and Al). Three compositions of ingots were examined, containing 0.0, 0.1, and 2 pct Cu, respectively. The alloys were melted in an alumina-lined salamander crucible using a medium-frequency electric induction furnace; when the appropriate casting temperature was reached, the alloys were cast without degassing or fluxing treatment. The mould used was made of electrode graphite and had the following dimensions: external diameter 6 in., height 9 in., with a mould cavity 8 in. deep and a diameter tapering from 5 in. at the top to 4 in. at the bottom. Casting temperatures used were generally in the order of 70" to 90°C above the liquidus and the mould was at room temperature before casting. Inserts kere placed in the mould cavity in some experiments. These consisted of either an 18-g stainless-steel tube of 2 in. diam held axially in the mould i in. off the bottom and extending 1 in. out of the top of the mould or a "trap-door" barrier of stainless-steel gauze of 24-mesh held horizontally in the mould 31/2 in. down from the top. The construction of this insert is shown in Fig. 1. All inserts were preheated prior to casting to prevent chilling. RESULTS The macrostructures of ingots of the three compositions are described, in terms of the three generally recognized zones, in Table I, and illustrated in Figs. 2(a) to (c). The most interesting observation in this table is that relating to the shape of the equiaxed grains, which were not in fact equiaxed but of almost tear-drop shape. Closer examination of these grains showed that each consisted of a head which had a coarse dendritic structure and a tail which always grew in the opposite direction to heat flow, and which had the same structure as that of the columnar material of the ingot concerned; i.e., in the pure aluminum and 0.1 pct Cu alloy it was cellular and in the 2 pct Cu alloy it was cellular-dendritic. Identification of original cast grains was greatly hampered in the super-purity aluminum ingots, and to a lesser degree in the 0.1 pct Cu alloy,

Jan 1, 1968

By Bruce E. Grant, Thomas Jancic, Lawrence G. Dykers, Frank Buchella

Principal factors influencing equipment selection can be grouped into five basic categories: tonnage requirements, ore and waste; topography and property line considerations; ore control requirements; physical characteristics of ore and waste; and climatic considerations. Loading, transporting and ground preparation equipment are largely determined by tonnage requirements. Large size equipment is appropriate for a production of about six million tpm, medium size for three million tons and small size for one million tons or less.

Jan 12, 1973

By Walter S. Tower

IN making comparisons of steel industries, one country with another, the convenient common denominator is annual capacity to make raw steel in the form of ingots. It is always necessary, however, to remember that there are different methods of figuring such capacity. For most countries no official figures on capacity are available, and the only authentic data on production are now six or eight years old. But in spite of those limitations on the accuracy of statistical comparisons, any flaws in the figures are probably not serious enough to alter materially the larger conclusions which may be drawn from them.

Jan 1, 1944

By J. C. Jaeger, G. A. Wiebols, N. G. W. Cook

It is usual practice in engineering to design a stable structure by ensuring that the stresses in the elements of the structure are always less than their strength, which may be defined as the yield stress, the ultimate stress, or the fatigue stress, according to the type of the load. Such restrictive design is not practical in the design of underground excavations since the rock surrounding such structures is usually failed, but only occasionally does this give rise to instability of the structure. Thus, while the usual criterion for the design of a stable structure is certainly sufficient, it is not necessary for underground excavations. A proper understanding of the conditions necessary for stability is vital to the useful application of rock mechanics knowledge to the design of underground structures. Most tests on the properties and strength of brittle rocks are disrupted at or near maximum load by the rapid release into the specimen of energy stored in the resilience of the testing machine. This is in contrast with a phenomenon, which may be observed frequently, where the rock immediately surrounding an excavation is both failed and subject to stress. By postulating a complete stress-strain curve for rock, it can be shown that failure is unstable or stable, depending upon whether the stress-strain curve of the rock lies inside or outside the stress-strain characteristics of the applied stress. Stability is, therefore, a function of the stiffness of the system applying the stress relative to that of the failing rock. Many workers have established that the strength of rock specimens under a lateral hydrostatic confining stress varies linearly with confining stress, in a way which may be expressed by the equation CT=Co+K[o]3

Jan 1, 1972

By John Blatchford, H. O. Hofman

The leading antimony mineral is stibnite. In smelting stibnite ore two processes are available, precipitation and roasting-reduction. The former is suited only for high-grade ores. As low-grade ores are more common than high-grade, roasting-reduction is of greater importance than precipitation. In the roasting process the aim may be to leave the oxidized antimony in the ore, or it may be to volatilize as much of the antimony as possible, collect the volatilized oxide as a rich intermediary product and smelt it for antimony, leaving the gangue poor enough to be considered a waste product. Whichever way the roast is conducted certain difficulties inherent in stibnite are encountered. These are: 1. The low melting point of stibnite which, according to Pélabon,' is 550°C., according to Wagemann2 540°C., and according to Borgstroma 546°C. 2. The ignition temperature: According to Friedrich,4 stibnite, if heated in air, begins to oxidize at 290°C. if the size of a grain is 0.1 mm. in diameter; at 343", if 0.1 to 0.2 mm.; and 430" if 0.2 mm. 3. The fusibility of a mixture of Sb2S33 and Sb203 which in the form of kermesite (Sb2S3)z.Sbz03 melts at 517°C.6 4. The volatility of Sb2Ss and SbzOs, for which no numerical data appear to exist, although practical experience has shown that they are volatile at low temperatures. As regards the oxidation of metallic antimony, we have the experimental evidence of C. F. Plattner6 that when fused and brought to a red heat, it burns with a bluish-white flame to Sb2Oa which passes off as a

Jan 1, 1916

By P. G. Beckett

THE problem of handling the large quantities of water encountered in the Old Dominion mine presents many features of interest. In the present paper are discussed the probable sources of water, the pumping equipment, the increased flow into the mine in the early part of 1915, culminating in the flooding of the 18th and 16th levels in March of that year, and the difficulties that were met with during the high-water period. I. PRELIMINARY The Old Dominion mine, situated 1 mile north of the town of Globe, Ariz., has long been one of the prominent copper producers of the State, and until the opening up of the copper schist deposits in the neighboring mines of Miami, was responsible for the greater part of the copper output from the Globe district. As the gradual exhaustion of its orebodies near the surface led to the downward development of the mine, more water was encountered in the western portions directly underlying the dacite formation until the drainage problem became a serious factor in the operation of the mine and in the economical extraction of the ore. A heavy inrush of water on the 10th level of the mine in 1906, preceded by still earlier water difficulties, rendered imperative the immediate installation of a pumping equipment capable of handling large flows of water. While the Old Dominion has been recognized as a wet mine since its early clays and one in which the complete control of the water situation was of paramount importance in the development of the lower levels, it is chiefly in the last nine years, since the installation of the increased pumping equipment, that the mine has developed and handled large quantities of water.

Jan 4, 1916

By Renato G. Bautista, Robert A. Hard

A comparative study has been made of the ex-tractability of several of the transitim metals from thiocyanate sohtions using methyl isobutyl ketone as the organic solvent. Extractions were made of scandium (III), chromium (III), manganese (II), iron (III), and cobalt (II), of which only the scandium , iron, and cobalt were readily extracted. All extractions were made at pH 2 and at 25.5 °C. A series of extraction experiments was made on scandium, iron, and cobalt to determine the effect of thiocyanate cmcentration added as the ammonium and also as the calcium salt. Also determined was the effect of metal ion concentratim and ionic strength on the distribution ratio. Analyses of the organic extracts indicated the scandium and iron were extracted principally in the uncharged trithiocyanate form, while the extractable form of the cobalt contained the cobaltotetrathiocyanate anion. THE chemical separation of metal complexes in solution by solvent extraction has in recent years been developed for large scale separation as well as bench scale work in the laboratory. It has also found increased application in analytical chemistry. Its extension to extractive metallurgy as a unit operation is best illustrated in the recovery of uranium and vanadium from their leached liquor.5-8 The extractability of some thiocyanate systems have been extensively investigated. The rate earths have been separated from one another using butanol as a olvent. Scandium was effectively extracted in ethyl ether using ammonium thiocyanate as the com-plexing agent.'' Similarly, the separation of hafnium from zirconium has been reported using ether""' or hexone13 as the organic solvent. The extractability of various metal thiocyanates in ethyl ether is given by 0ck.l Sharp and Wilkinson15 prepared nickel-free cobalt slats by thiocyanate extraction. The mechanism of extraction of titanium (IV) thiocyanate with methyl isobutyl ketone was determined by elafosse.''" The characterization of cobalt (TI) thiocyanate complex using methyl isobutyl ketone as the solvent at near neutral aqueous solution and the spectrometric studies of the ex-tractable cobalt complex has been made by Hard." It is noteworthy to mention at this point that the fundamental characteristic of ketone (oxonium) solvent extraction is that the extractable species are uncharged ion pairs solvated by the ketone molecules, but probably still partially hydrated.

Jan 1, 1963

By Sir Robert Hadfield

Table 1 gives the composition of the specimens listed by the author. The details of test procedure and the results of the tests on mechanical, magnetic and electrical properties and cor-rodibility of the alloys are published in full in a paper by the same author, "Alloys of Iron and Manganese Containing Low Carbon," presented before the Iron and Steel Institute (of Great Britain) and published in full in their Proceedings for 1927, to which reference should be made. After reporting these tests the author gives the following discussion of results:] The studies here reported do not indicate that any of the series has really valuable or useful qualities for industrial applications, though the demands of industry are so varied that it is unsafe to prophesy that no special use will be found for a given material. The non-magnetic property of manganese steel is due to the association of Fe and Mn, but carbon has also an effect, enabling non-magnetic qualities to be obtained with a much lower percentage of Mn than would otherwise be the case; for example, 16 per cent. Mn is necessary for alloys practically free from carbon, while with 1 per cent. C nonmagnetic alloys may be obtained with as little as 7 per cent. Mn. Carbon, however, is the prime cause of the development of magnetic qualities by heat treatment. (Sec section 8 of the paper referred to above.) These Fe-Mn alloys show a resistance up to 87 microhms per c. c., but. as there are other alloys which have a resistance as high as 130 microhms per C. c., this does not provide any new feature of value. The most marked feature of the series studied is the brittleness in the range 3 to 10 per cent., with a maximum of brittleness at 7 per cent. Material with this percentage, while possessing quite appreciable hard-

Jan 1, 1927

By J. A. Church

I. Early Furnaces,......423 11. Experiments with the HIgh-Shaft FURnace,..... 426 III. ExperMents wIth the Wide FURnace,..429 IV. ExperEentS with Extreme BOSH,... 43.2 V. Survival of the 56 by 180 IN. Furnace,.434 VI. Recent ExpeEiments,.....436 VII. SUMMary,........438 I. Early Furnaces. Copper blast-furnace construction in America has long recognized a general standard in the rectangular water-jacketed shaft with separate forehearth. The details, however, and especially those relating to shaft dimensions, have had to meet a great variety of conditions, and show no uniformity whatever. Selecting a few of the present day Western plants, we find furnace lengths varying from 12.5 to 87 ft., widths at tuyere level from 42 to 84 in., and heights above tuyeres from 5 ft. 4 in. to 22 ft. 4 in.; and comparing present designs with those of the past, we meet contrasts no less striking. Unlike its transverse section, the length of a furnace has come to depend rather on the size of unit desired than on the requirements of smelting; and if the question of length be ignored, several of the various existing designs can be grouped together on the basis of a common transverse section. This section, having a width at tuyere level of 56 in. and a height above tuyeres of 18 ft., was developed at Great Falls, and the story of its development contains some interesting features. Ground was broken for the Great Falls works in the spring of 1891. About a year later, the concentrator was able to begin operation, followed within the next few months by the Brueckner, reverberatory, and converter departments, and in April, 1893, by the first blast fur-

Jan 1, 1914

• One effect of the British devaluation of the Pound Sterling, with its resultant lowering of the pay limit, was the addition of considerable tonnages of previously marginal ore in gold mining. Crown Mines, Ltd., reported that 1,245,000 tons of such ore had been added to available reserves. But for devaluation, a steady decline in ore reserves had been a feature of operations during the previous ten years, and would have continued. •Loree Colliery of the Hudson Coal Co. is using a Humphrey spiral cleaning plant to meet requirements of the state in the matter of stream pollution. However, the process is producing a salable product. •Noranda is considering plans for constructing a commercial sized unit designed to produce elemental sulphuric acid and sintered iron oxide from pyrite. Test plant results have indicated the No. 5 ore zone can be treated by the new process economically. •A magnetic fluid clutch, and magnetic amplifiers for motor and generator control, have been developed under Navy contract by Vickers' Electric Division, in St. Louis, Mo. This constitutes the first commercial production of the clutch recently developed by the Bureau of Standards. •Fuel experts estimate coal production will run up to 500 million tons this year based on the expectation that business conditions will continue to be good. They also expect that in the future the use of coal will increase by 50 pct over today's level. These expectations are based on the fact that it provides the bulk of the heat, light, and power for making steel, for manufacturing, and for generating electricity as well as the development of the coal burning gas turbine and processes for making gas, gasoline, and oil from coal. •Entombed miners may benefit from a two-way communication system which utilizes the earth's strata as a network for electric signals. The use of FM radio waves makes this possible. The invention includes a portable transmitter-receiver unit kept near the face, and a more powerful portable equipment of the same sort above ground. In use, two probes on wires from the apparatus are driven into the earth. • The Union of South Africa has launched a uranium production project which government leaders think will help the West maintain world atomic supremacy. Experiments under way in the pilot plants are expected to lead to the establishment of a chain of processing factories along the Witwatersrand in which uranium will be reclaimed from gold tailing. •Recent developments in mechanized mining at the Bureau of Mines oil-shale mine near Rifle, Colo., have lowered mining costs to 29 cents per ton of shale. The cost of producing crude shale oil from 30-gal-per-ton-shale, using the new mining and processing techniques, would be about $1.50 per barrel. This is 500 lower than any previously stated price. • COMINCO is planning to open the old Bluebell lead-zinc mine near Nelson, B. C., on a 500-ton-per-day basis. The old workings will be pumped and a 970-ft incline sunk. A mill will be constructed at the property.

Jan 7, 1950

By H. Hubert

THE first attempts at direct utilization of blast-furnace gas in engines were made in 1895. For a considerable time the gas had been burnt in Cowper stoves for heating the blast for the furnace, and under the boilers which supplied steam to the blowing-engines, and others serving the furnaces. It was natural, therefore, that the idea of directly employing it in gas-engines should have occurred simultaneously to several engineers, notably to Lürmann and to Lencauchez, who had pointed out the blast-furnace as a powerful -gas-producer. Nevertheless, nowhere had any attempt been made to apply it to this purpose up to the end of 1894, when Thwaite proposed it to Mr. James Riley, of the Glasgow Iron & Steel Company. About the same time investigations were being made in Belgium and in Germany, independently of Thwaite's experiments, which were not generally known on the Continent. The industrial world, which up to that time had hardly favored the idea, had thus been gradually prepared to receive it. The gas-engine, long restricted to small sizes and dependent upon the use of an expensive fuel obtainable only in large centers, now began to make headway. At the Paris Exhibition of 1889 two engines of 100 h.p. were shown and excited much interest among engineers. One had four cylinders, and was made at the celebrated works of the Deutz Company, and the other was a single-cylinder engine, exhibited by two French designers, Messrs. Delamare-Deboutteville and Malandin. In the meanwhile the design of gas-producers had made important progress, completely freeing the new engine from its

Nov 1, 1906

By W. H. Furlonge

WHILE fulfilling professional engagements, my travels over this portion of the Transvaal have been quite extensive—always on horseback however, so that anything like a thorough investigation of the ground passed over has been necessarily impossible; still, the more minute examination of certain small areas, coupled with general observations, has enabled me to form some idea as to the prominent geological features of the country as a whole. Anything like a complete or comprehensive description is indeed out of the question, as there are no proper maps of the country and the facilities for observation are limited. A large plateau, called the "High Veldt," stretches from east to west across the Transvaal. It is generally level, or gently rolling, and has an average elevation of 6000 feet above the sea; it is destitute of timber, and in fact greatly resembles the western prairies of North America. Rock-outcrops are not common in it. It terminates very abruptly to the east and northeast, the descent of 2000 or 3000 feet into the mountainous country that occupies its borders being made in a

Jan 1, 1890

By M. Gensamer, B. Lustman

A recent paper described, by means of stereographic pole figures, the preferred orientations produced by cold-rolling low-carbon steel of automobile-body grade. It was found that the surface of the sheet exhibited a deformation texture significantly different from the texture possessed by the inside of the sheet. Efforts to produce the surface texture by buffing a sample exhibiting the normal or inside texture, using a copper lap, have not been successful. In view of the data collected by Kurdjumow and Sachs2, it was suggested that the surface texture might be the result of partial recrystallization of the normal or inside texture. The recrystallization texture of cold-rolled mild steel was studied by Goss3, but he did not use the pole-figure method, so that his conclusions were in need of verification. For these reasons the work reported in here was undertaken. It had two objectives: (1) to study the general behavior of cold-rolled mild steel on recrystallization below the critical temperature Al, and (2) to attempt experimentally a demonstaration of the genesis suggested above for the surface texture in cold-rolled steel. The material was that used by Gensamer and Mehl, cold-rolled to 97.5 per cent reduction in thickness. Fig. 1 is an X-ray pinhole photo-gram of this material, taken with the beam transmitted perpendicular to the plane of the sheet, using a molybdenum target at 35 kv. with no filter. It is typical of the inside texture, but in it the deformation texture is better developed than in the samples that showed a well developed difference between the inside and surface samples. Specimens from this sheet, which was 0.005 in. thick, were annealed for 5 min. at various temperatures in a lead bath. After about 0.0005 in. had been etched from both surfaces, X-ray photograms were prepared, using the technique described in the earlier paper1. Figs. 2 to 6 are photograms of the annealed sheet, at 566, 571, 577, 580 and 650" C. (1050' to 1202" F.), in order. Fig. 2 shows that 5 min.

Jan 1, 1937

By J. P. Nielsen

When two grains in a polycrystalline specimen meet at a point in the course of grain-boundary movements, and the new boundary created at the point is one of relatively low specific free energy, a nonequilibrium boundary condition occurs. The nonequilibrium is enhanced if the other grain boundaries involved at the point of meeting are relatively high in specific free energy. The nonequilibrium results in a correction by growth of the complex grain (two subgrains) to a large size, sufficient in many cases for it to become a self-propagating unit, i.e., a recrystallization grain. This mechanism, herein called "geometrical coalescence," is proposed as a logical origin for recrystallization nuclei, particularly for secondary recrystallization. RECENT publications1-' indicate that considerable progress has been made toward a complete understanding of the three microstructural processes in metals: recovery, recrystallization, and grain growth. However, a major problem persists, namely, the origin of recrystallization nuclei. It is generally accepted that once a recrystallization nucleus, a secondary recrystallization nucleus particularly, has reached a certain size, it will continue to grow at the expense of its neighbors, simply as a consequence of grain-boundary free-energy considerations. What has remained obscure, however, is the mechanism whereby such a nucleus comes into being and grows to the self-propagating size. Recrystallization Nucleation in a Two-Dimensional Grain-Boundary System In the left portion of Fig. 1 is shown schematically the meeting of grains 1 and 4 on disappearance of boundary 2-3, i.e., the boundary that existed between grains 2 and 3, as might happen in the course of normal grain-boundary migration. If, by chance —and the probability is not necessarily small— grains 1 and 4 are close together in their mutual orientations, or in some other special way mutually oriented so that the new common boundary has relatively a very low specific free energy (hereinafter referred to by s), then the grain boundary arrangement as depicted in the figure is highly unstable. This is particularly so if boundaries 1-3, 3-4, 4-2, and 2-1 are high in their s values. Assuming, for the sake of argument, that boundary 1-4 has a s equal to zero, and the s's of all the other boundaries present are equal to each other and constant, then the boundary arrangement on the right in Fig. 1 will be

Jan 1, 1955

By Frank R. Barnako

Coal mining is a hazardous occupation, but tremendous progress has been made in reducing accidental injuries and deaths in the mines. Let us take a look at the hazards in coal mining and the accident record. COAL MINE SAFETY TODAY Underground coal mining creates underground open areas, rooms, and haulageways. The roof (top) and ribs (sides) become highly stressed, and because coal and slate are very weak in tension or compression they frequently fail and fall from the roof and ribs unexpectedly. This is the most hazardous condition miners must cope with underground, and it has consistently produced the greatest number of fatal injuries in the coal mining industry. Only very sophisticated equipment, but which is not yet practical for use underground, is able to detect the buildup of stresses that may eventually lead to a roof or rib fall. Today's miner still looks for fresh cracks in the roof or rib, listens for the "drummy" sound, and feels vibrations from loose material in the roof, when tapped with a sounding stick, in order to find material which may fall. Once located, it is barred down, but if this is not possible, it is then secured to prevent it from falling. The next great& hazard is the equipment used to mine or haul coal. It is large, heavy, reacts quickly to its controls and is operated in con- fined areas with low lighting levels. The record of the last few years shows that fatalities attributable to mining and hauling equipment are about equally divided. Thorough training as part of a complete safety program is necessary to teach employees the hazards of loose roof, rib, and machine operation in order that they can work in the safest way possible. Unless there is such a program, the trade is learned by trial and error with a resulting tragic.

Jan 1, 1973

Briefly, an open stope is one in which the ore is taken out and no filling is put in; the only support for the walls may be posts or pillars of ore. Such a method is limited to orebodies with strong walls and ore strong enough to stand unsupported over the back of the stope. Details vary and depend on the dip of the vein, mode of breaking ground, method of handling broken ore, and so forth. The examples given are the Beat-son, Birmingham district, Mineville district, and Cornucopia.

Jan 1, 1925

By Otto H. Henry, J. J. Cordiano

THOUGH powder metallurgy is one of the oldest of metallurgical processes, it is in its infancy as a branch of the modern field of metallurgy. As early as 3000 B.C., the ancients produced implements and weapons of iron by reducing iron ore in a charcoal fire and forging the resultant sponge while still hot into the desired shape. Melting and casting soon superseded the powder metallurgy practice, and it was not until the turn of the twentieth century that powder metallurgy was applied to the commercial manufacture of tungsten lamp filaments. From this beginning, the use of the powder metallurgy process spread to the manufacture of porous oil-impregnated bearings, cemented carbide tools, contact points, diamond grinding wheels, clutch facings, starter brushes, resin-bonded radio cores, magnets, metallic filters, and other parts. More recently, and particularly during the present war, there has been a definite trend toward the manufacture of machine parts by this process in competition with the more conventional fabricating methods. Notwithstanding these many developments, scientific progress has been slow. While many articles on powder metallurgy have appeared in the press and various publications, there have been too few contributions to our technical societies, with the result that there is a dearth of the type of information necessary for the full development of this science. It is of primary importance that the results of research and development be freely disseminated if powder metallurgy is to realize its fullest potentialities. PURPOSE OF INVESTIGATION Excluding the refractory metal field, all commercial powder metallurgical products made by a cold compressing and sintering operation contain voids. These voids can be substantially eliminated by subsequent severe working and heat-treatment, but such practice has not proved economical in most applications. By applying heat during the compressing operation, plastic deformation of the powder particles is substantially increased, and the resultant compact or briquette is practically free of voids. However, hot-pressing has many attendant problems, which at present preclude its use in the manufacture of precision parts. The more important of these are to devise: I. A die steel capable of withstanding high pressures at elevated temperatures. 2. A high-temperature lubricant capable of preventing excessive die wear and welding of the compact to the die walls. 3. A method of retaining a neutral or reducing atmosphere in the compacting zone of the die assembly. 4. A means of ejecting the hot-pressed specimen into a neutral atmosphere until reasonably cold.

Jan 1, 1945

New York Meets first Wednesday after first Tuesday of each month. DAVID H.-BROWNE, Chairman, JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE, Secretary, 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. . ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 11, 1915

By James G. Crawford

Correlation Of water with its reservoir zone or formation has been one of the applications of oil-field water analysis of greatest direct value to the petroleum engineer. The water in each producing zone tends to have diagnostic characteristics by which it can be distinguished from every other water above or below that zone in that immediate vicinity. Representative analyses of oil-field waters from producing oil and gas fields in the Rocky Mountain region are included, and the diagnostic characteristics are discussed briefly. It is concluded that the generally dilute nature of Rocky Mountain oilfield waters is a result of dilution by meteoric waters, and that there is no relationship between presence or absence of commercial oil and the character of water in a structure. Introduction The study of waters associated With oil and gas began more than 50 years ago and has been well recognized by operators, engineers, and geologists for about 30 years. It appears unnecessary at this time to recite the history of oil-field water analysis; suffice to say that it has proved its worth many times to the production engineer suddenly confronted with water problems in producing oil and gas wells. Chemists and geologists have studied the possible origin of these waters and as Yet the subject is unsolved in many important phases. There are both local and regional problems connected with the explanation of concentrations and character- istics peculiar to each field, each subsurface zone and each province. Criteria useful in postulating the Occurrence of oil Or gas in One province completely fail when applied to another, and data carefully prepared and analyzed from one field may be actually misleading when applied to another. Correlation of water with its reservoir zone or formation has been one of the applications of oil-field water analysis of greatest direct value to the engineer. The concentrations and characteristics of the waters are essential to the engineers and geologists making interpretations of electric logs in this region. The behavior of water under conditions of reservoir temperature and pressure is dependent to a great degree upon its concentration and characteristics, and thus important to the reservoir engineer. With the advent of secondary recovery methods in the Rocky Mountain region the characteristics and treatment of water will become increasingly important. Premises upon which Correlation Is Based A brief review of the geochemical history of oil-field waters will suffice to present the premises upon which correlations of the waters are based. Sedimentary rocks which are now stratified were first sediments in seas, lakes and streams. These sediments were filled interstitially with connate water. With burial the sediments were compressed arid consolidated, integrated and indurated into bed rock and much of the connate water was dispelled. Following the formation of bed rock the strata were sub-

Jan 1, 1949

By John Norton

THE tremendous increase in the use of metals that have been prepared by the various cold-working processes during recent years has greatly stimulated the investigation of problems concerned with the fundamental nature of these processes. It has been observed in practice that different methods of bringing about the same dimension changes in a sample result in a rather wide range of properties. Cold working reduces the ductility of a metal, or what is perhaps more nearly correct, its "working capacity," and naturally the manufacturer wishes to produce an article that has as large a working capacity as possible, and to produce it with the smallest number of operations, It has also been known for some time that cold deformation produces a parallel alignment of the crystal grains of a metal, and that the type of this preferred orientation depends to some extent at least upon particular processes employed in the deformation. The present investigation has for its purpose the study of the relations between the various factors of a cold-working process and the preferred orientation of the metal crystals resulting from this deformation. The work is chiefly confined to a study of cold-drawn seamless tubing.

Jan 1, 1932