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Jan 1, 1925

By B. E. Eakin, A. L. Lee, M. H. Gonzalez

Expeximental viscosity and density data of lour natural gases are presented for temperatures from WO to 340F and pressures from 100 to 8.000 psia. A correlation is also discussed and results reported. INTRODUCTION This investigation is one of several efforts by the authors to provide viscosity data for pure hydrocarbons and mixtures. Results of some pure hydrocarbons and their mix tures have been presented." Several predictive methods and correlations have also been reported.'," This paper presents the experimental viscosity and density data of four natural gases and confirms a correlation in a previous study. APPARATUS The viscometer was described previously. 2,6 A bank of stainless steel pycnometers was included to determine density in conjunction with the viscosity measurements (Fig. I). DATA AND MATERIALS The natural gases were furnished by the Atlantic Richfield Co. (Samples 1 and 21, the Continental Oil Co. (Sample 3) and the Pan American Petroleum Corp. (Sample 4). Table 1 shows the composition of these gases obtained by mass spectrometer analysis. The pure component viscosity data used in the correlation have been published."".'"', '" Experimental and calculated viscosity data for the natural gases are presented in Tables 2 through 5. CORRELATION Starling and Ellington"' have reported several semi-empirical expressions based to a certain extent on the theory of viscosity advanced by Born and Green.' The final expression presented by Starling and Ellingto'n is: i'. (micropoise) -- /t,, exp rX(7') p ..... (I) Eq. 1 was modified by Lee et 01." to represent mixture and pure component data simultaneously. This equation has the form: F = K exp [XpY] :.........(2) where K=- (7.77 i 0.0063M)Ti 122.4 + 12.9M +T .................(3) ' ' ' X= 2.57 + ---1914.5+ 0.0095M .... (4) Y = 1.11 -r 0.04 X ........(5) Over the pressure and temperature range studied in this investigation, this equation represents the data on methane, ethane, propane, n-butane and four methane-n-butane mixtures with a standard deviation* of ? 1.89 per cent. Density data by Sage and Lacey" were used to fit the equations. Eq. 2 gives reliable values of the viscosity of light hydrocarbons without prior knowledge of experimental viscosity values, but accurate density data must be available. Eq. 2 was used to predict viscosity values for the natural gases studied in this paper. The particular set of parameters contained in Eqs. 3 through 5 gave values that reproduced experimental data within 25 per cent. Needless to say, in using Eq. 2 better density values will give better viscosity results. However, those engineers who do not have accurate density values at hand or the time, or such facilities as a library, computer, etc. readily available, may feel uneasy in using Eq. 2. Therefore, the authors sought the easiest but by no means best density prediction method, which was reported by Kaf 30 years ago. A set of density values, which were calculated based on Kay's method, and a generalized compressibility factor chart were used to fit Eq. 2. The results are:

Jan 1, 1967

By W. A. Backofen, A. T. English

The kinetics of re crystallization were determined metallographically for a 3-1/4 pcl Si-Fe rapidly compressed at temperatures of 710° to 911°C, and held for various times at the working temperature. As in re crystallization following cold wwk, the time for re crystallization was reduced by increased temperature and strain. Nucleation occurred chiefly at grain edges, although other pre-existing interfaces, notably inclusions, also served as nucleation sites. The importance of intragranular nucleation to grain refinement in hot working is pointed out, together with some possible techniques by which nucleation might be induced within the grains. The observed isothermal growth rates are quite accurately described by the equation G = 4 x 10-'/t (cm per sec), independent of temperature and strain at all but the shortest times. Changes in G during recrystalliza-tion can exceed two orders of magnitude. It is argued that release of stored energy associated with lattice defects cannot adequately explain the time dependence. A suggested alternative involves processes of solute segregation and desegregation in the unrecrystallized matrix and at the moving boundary, respectively. EFFORTS to improve hot-working practice are hampered by an incomplete understanding of the fundamental metallurgy involved. Research directed at establishing the required basic foundation falls into two categories, the first concerned with measurement of mechanical properties under the conditions of high temperature and strain rate which characterize such processing, the second focused on structure and its relation to the deformation conditions. Rossard,' Rossard and Blain,2 and Hardwick and Tegart have conducted many high-speed, high-temperature torsion tests on various metals. One of their objectives was interpretation of stress-strain curves in terms of the structures of specimens rapidly quenched following interruption of twisting. They showed that appreciable hardening occurred in the early part of the test, and that this hardening reflected the concurrent development of an increasingly dense substructure within the grains. The detailed nature of this substructure was observed to depend on the ease of polygonization which, at least in fcc metals, varies with the stacking-fault energy.= By holding specimens after interruption but before quenching, the nucleation and growth of new grains could also be studied. Some success has been realized in relating the microstructure of hot-rolled steel to its temperature:strain rate:strain history with such testing.' The same general observations have been made by others investigating rolling4f5 and drop-hammer forging.~-~ Incident to these experiments, some efforts were made to determine the kinetics of re-crystallization as well as the velocity of the migrating boundaries. The results have been largely qualitative, owing to difficulties of interpreting hardness measurements5 and microstructures. The work described here was undertaken to obtain more quantitative information from tests on a material having suitable metallographic properties, and, in this way, to provide further insight into the fundamentals of this practically most important kind of deformation processing. I) MATERIALS AND EXPERIMENTAL TECHNIQUES Materials. Electrolytic etching of a Si-Fe alloy reveals dislocations and substructure in unrecrystallized grains.8'9 This unique characteristic makes possible a precise determination of the extent of recrystallization. For that reason, it was the material selected for all experiments in the present work. The two particular alloys that were used are identified in Table I. A major difference between "A" and "B" is the number of inclusions, as noted in the table. Most of the experiments were made with material "A". It was received as hot-rolled plate 1 in. thick, sawed to 2-in. widths, hot-forged at 1200°C to 5/8-in. rounds, and finally annealed in a mechanical vacuum at 1000°C for 24 hr. The result was substructure-free grains of mean diameter 0.05 cm.*

Jan 1, 1964

By AIME AIME

IN furtherance of the policy of acquainting those members of the Institute who live at a distance from New York with all the details of administration, the thirty delegates sent by the local sections and the technical divisions were invited to attend the meeting of the Directors on Tuesday evening as well as the Directors' dinner immediately preceding. Including the Directors and officers, new and old, the members of the Papers and Publications Committee and the section delegates, more than 70 sat down at the dinner table in the Engineers Club. The attendance at the business meeting that followed was not quite so large, doubtless for the reason that the ladies' fashion show, held in connection with the informal dance, offered attraction that eclipsed that of watching the wheels of Institute business go around.

Jan 1, 1930

CONTENTS PAGE HESSE, A. W,-Safeguarding Coal-mining Operations against Danger from Oil and Gas Wells. Discussed by A. W. Hesse, T. G. Fear, George H. Ashley, George S. Rice, W. E. Fohl, R. V. Norris, S. A. Taylor, F. B. Tough, C. W. Gibbs, A. Hurlburt, S. W. Meals 1 DAWSON, THOS. W.-Belt Conveying of Coal at H. C. Frick Coke Company Mines. Discussed by F. F. Jorgensen, Thos. W. Dawson, Graham Bright, A. W. Hesse 13 OTTO, HENRY H.-Ultimate Recovery from Anthracite Coal Beds. Discussed by R. V. Norris, S. A. Taylor, Henry H. Otto, Douglas Bunting, Graham Bright, Howard N. Eavenson, J. B. Warriner 15 HOSLER, Rush N.-Schedule Rating Coal Mines in Pennsylvania for Compensation Insurance Rates. Discussed by E. A. Holbrook, W. W. Adams 17 ARCHBALD, HUGH.-Application of Gaussian Curve to Mining Industry. Discussed by Donald A. Laird, T. T. Read 19 ASH, SIMON H.-System of Coal Mining in Western Washington. Discussed by Eli T. Conner, Simon H. Ash 21 MILLER, J. S.-Method of Mining a Steeply Pitching Anthracite Vein by Successive Skips. Discussed by Eli T. Conner, J. S. Miller, J. B. Warriner 22 HARRINGTON, GEORGE B.-New Orient, an Unusual Coal Mine. Discussed" by George S. Rice, Eli T. Conner, John A. Garcia, George B. Harrington, F. F. Jorgensen, Graham Bright, W. M. Hoen, George N. Simpson, W. C. Adams, R. W. McNeill, Chas. C. Whaley, Carl Scholz, E. T. Gott, Andrews Allen 23 PERROTT, G. ST. J.-Properties of Liquid-oxygen Explosives. Discussed by George S. Rice 48 Safeguarding Coal-mining Operations against Danger from Oil and Gas Wells Discussion of the paper of A. W. HESSE, presented at the New York Meeting, Feb-ruary, 1925, and issued, as Paper No. 1412-F, with MINING AND METALLURGY, February, 1925. A. W. HESSE.-The well under investigation, No. 101, Fig. 2, was started about Sept. 5, 1921, and drilled-in in November. The first hole was started with a 13-in. bit and reached the Pittsburgh coal at a depth of 563 ft.; at 602 ft. the 10-in. casing was run in and the well was continued with a 10-in. bit and 1400 ft. of 8-in. casing was put in. It was then continued to a depth of 1770 ft. and 6-in. casing put in; then continued to a depth of 2555 ft. where the gas was struck. As the well produced only about 100,000 cu. ft. per day. 2-in. tubing was used to conduct the

Jan 6, 1925

I am much pleased by your presentation of my article and flattered to the extent that the cover design refers to it. Incidentally, as between folks who like to work with words, refer to line 6, second full paragraph, page 773 (August Mining Engineering) Would "for" preceding technological have changed the percentages in lines two and three of the bold-face heading on page 770? The intent was coequality among three, (studies of mankind, of science, and of technological empirics). Thirty-three pct for "man" studies is a pretty big bite for engineering schoolmen; 50 pct they won't even examine, let alone nibble at. Arthur F. Taggart For those of you without a copy of the August issue handy, the sentence referred to read: The plea herein is to make the overall time allotment for studies of mankind coequal with those, for science and technological empirics.... Professor Taggart suggests that insertion of the word "for" would clarify the intent of coequality among three divisions of study: The plea herein is ... for studies of mankind coequal with those for science and (for) technological empirics. Editor.

Jan 1, 1952

By S. Fróes Abreu

The importation of liquid fuels in Brazil amounts to about 1,300,000 tons; 30 per cent of this total being gasoline for automobiles and airplanes. Statistics show an increasing consumption of gasoline notwithstanding the use, daily greater, of fuel alcohol, a domestic fuel of low cost in the producing areas. The Brazilian market for petroleum products has shown a tendency to grow as the country has steadily developed— expansion of the industries in the areas already developed, and also the recent occupation and population of new zones. The war has brought many difficulties to Brazil. It has limited the importation of petroleum products, which came mostly from the United States, Venezuela and Mexico. During the first days of the present crisis automobile and truck traffic was vastly curtailed; but the national activity in the production of more fuel alcohol, and principally in the development of producer gas, has done much to provide a solution for the transportation crisis threatened at the beginning of the gasoline shortage. Many thousands of cars and trucks in Brazil are now burning producer gas made from charcoal. Producer gas for automobiles has been improved by Brazilian engineers and many new types have appeared. - Production There is only one producing oil field in Brazil—the one in the State of Baia, near the Baia de Todos os Santos. The first producing oil well was drilled in Lobato in 1939 by the Federal Government following studies carried on in that area by Oscar Cordeiro, S. Froes Abreu, G. Paiva and J. Amarai. The field and laboratory work done by these men was published in 1936 in a paper entitled " ContribuicBes para a Geologiado Petroleo no Reconcavo (Baia)," which indicated the potentialities of the area as an oil producer. After the discovery of the first producing well, the Brazilian Government issued a decree establishing an area, 60 km. in radius, as a National Reservation. This first well was drilled in Lobato. In no other locality in Brazil is any petroleum produced. Although many wells have been drilled in the southern part of Brazil, on the northeastern coast and in the Amazon Basin, they yield nothing. Actual production is below 1000 bbl. daily. The producing area covers Itaparica Island, Candeias and Arath, Joanes Island and Lobato. Since very little geological information was available, especially about subsurface structure, it was necessary to drill several wildcats in order to collect the data essential in the choosing of good locations. The United Geophysical Co. was contracted to perform a geophysical survey to clear up the major problems concerning the oil deposits in the Reconcavo beds. The best wells in Reconcavo are on Itaparica Island, where the daily flow amounts to about zoo bbl.; in other sectors production is considerably lower and most of the wells are pumping. In the Aratfi sector, near an area of very light oil, there is an important gas field, with wells producing about I0,000,000 cu. ft. daily.

Jan 1, 1944

By S. Fróes Abreu

The importation of liquid fuels in Brazil amounts to about 1,300,000 tons; 30 per cent of this total being gasoline for automobiles and airplanes. Statistics show an increasing consumption of gasoline notwithstanding the use, daily greater, of fuel alcohol, a domestic fuel of low cost in the producing areas. The Brazilian market for petroleum products has shown a tendency to grow as the country has steadily developed— expansion of the industries in the areas already developed, and also the recent occupation and population of new zones. The war has brought many difficulties to Brazil. It has limited the importation of petroleum products, which came mostly from the United States, Venezuela and Mexico. During the first days of the present crisis automobile and truck traffic was vastly curtailed; but the national activity in the production of more fuel alcohol, and principally in the development of producer gas, has done much to provide a solution for the transportation crisis threatened at the beginning of the gasoline shortage. Many thousands of cars and trucks in Brazil are now burning producer gas made from charcoal. Producer gas for automobiles has been improved by Brazilian engineers and many new types have appeared. - Production There is only one producing oil field in Brazil—the one in the State of Baia, near the Baia de Todos os Santos. The first producing oil well was drilled in Lobato in 1939 by the Federal Government following studies carried on in that area by Oscar Cordeiro, S. Froes Abreu, G. Paiva and J. Amarai. The field and laboratory work done by these men was published in 1936 in a paper entitled " ContribuicBes para a Geologiado Petroleo no Reconcavo (Baia)," which indicated the potentialities of the area as an oil producer. After the discovery of the first producing well, the Brazilian Government issued a decree establishing an area, 60 km. in radius, as a National Reservation. This first well was drilled in Lobato. In no other locality in Brazil is any petroleum produced. Although many wells have been drilled in the southern part of Brazil, on the northeastern coast and in the Amazon Basin, they yield nothing. Actual production is below 1000 bbl. daily. The producing area covers Itaparica Island, Candeias and Arath, Joanes Island and Lobato. Since very little geological information was available, especially about subsurface structure, it was necessary to drill several wildcats in order to collect the data essential in the choosing of good locations. The United Geophysical Co. was contracted to perform a geophysical survey to clear up the major problems concerning the oil deposits in the Reconcavo beds. The best wells in Reconcavo are on Itaparica Island, where the daily flow amounts to about zoo bbl.; in other sectors production is considerably lower and most of the wells are pumping. In the Aratfi sector, near an area of very light oil, there is an important gas field, with wells producing about I0,000,000 cu. ft. daily.

Jan 1, 1944

By L. J. Ingvalson, Roy H. Miller

IN 1948, as part of a program to expand the copper tube mill facilities of the American Brass Co. plant at Kenosha, Wisconsin, plans were formulated to convert the 100 ton capacity anode casting furnace at the Great Falls, Montana plant of the Anaconda Co. to the production of 3 in. phosphor -ized billets. The furnace was rebuilt completely and construction was started on an addition to the building. Members of the Great Falls staff visited various billet casting plants to draw upon the experience of other producers of this type of casting. Many features of other plants were incorporated into the Great Falls plant but, in addition, many new designs were made and perfected to make the plant the most advanced of its type. Construction was begun in 1949, with the intention of having the plant in production in the early part of 1951. In January 1951, as the plant was being rushed to completion, the government placed restrictions on the production of copper tubing. As a result, work was halted and the plant lay idle for two years. Interest was reactivated in May 1953 with the lifting of restrictions on copper. Plans were laid to go into production in July and the first charge was taken out July 1, 1953. Basically the plant is designed to produce from cathode copper a 3 in. diam billet, 50 in. long. weighing 110 lb, and containing 0.013 to 0.036 pct P, at a rate of 150,000 Ib per operating day. These billets are to be pierced and drawn into tubing. Furnace The furnace is a 100 ton capacity reverberatory type, gas fired furnace; 21 ft long and 9 ft wide. Gas is introduced to the furnace through two 38 hole Mettler gas burners. These burners are of chrome nickel alloy with four jets per hole. The furnace is charged with cathodes from the Electrolytic Copper Refinery plus return scrap from the casting operation by means of a Wellman Seaver Morgan Co. 7,000 lb capacity charging machine. The charge crane has a 20 ft boom and fork peel provided with an air ram to push material off the peel. The machine travels on overhead tracks and can be moved in any direction. The boom can be raised and lowered and swung through an arc of 180". With well stacked units of 6,000 lb, an experienced operator can put the first charge into the furnace in 40 min. After charging, the steel framed silica brick charge door is put in place and sealed with clay. After melting and skimming off the slag, the copper is blown until an oxygen content of 0.40 pct is reached. The metal is then heated to 2180°F, covered with coke, and poled. Poling is continued until a 3 in. diam test billet, 8 in. long, shows a flat set. The oxygen content is usually 0.030 pct at this time. At the end of poling, a temperature of 2160" to 2180°F is desired. In the side of the furnace opposite the charging door is the taphole slot, extending 36 in. upward from the bottom of the furnace. It is 4½ in. wide at the outside face and widens to 9 in. at the inside face of the furnace. It is filled with a wet mixture of sand, fireclay, and crushed coal. Flow of metal

Jan 1, 1957

By M. R. HULL

FOLLOWING the discovery of a body of ore that appears to have commercial possibilities there is a period of development work to determine its extent and grade and the most economical method of mining it. Laboratory tests are made in an effort to determine the most practicable and economical treatment for the extraction of the valuable constituents of the ore and these tests are carried farther and checked in a pilot or test mill. The rate at which the ore is to be mined and the daily capacity of the plants that are to treat it will depend on a number of important factors such as: The size of the orebody; the capital available for building the plants; the market or demand for the final product; the supply of skilled and common labor available for the construction, operation and maintenance of the plants; the quantity and quality of available water, and the amount and cost of power that can be purchased or that can be economically developed. Having decided on the treatment that is to be given to the ore and after full consideration of the above factors the management decides to erect a reduction plant of a given capacity.

Jan 1, 1926

By Richard H. Bube

Photoelectronic radiation detectors may be conveniently classified as homogeneous intrinsic, homogeneom extrinsic, or junction type. Highly photosensitive homogeneous intrinsic photodetectors may be prepared from a number of different II-VI, III-V, or IV materials. Such materials require the presence of specific imperfections that can act as sensitizing centers to provide long majority carrier lifetime. Homogeneous extrinsic photodetectors are of interest primarity for infrared detection, and consist principully of germaniuim and silicon with suitable inpurities. A vaviety of junction photodetectors exist, with silicon us the most common material for them all. The following extrema in performance are found: 1) highest photoconductivity gain in homogeneous intrinsic photodetectors; 2) smallest response time (highest frequency response) in p-i-n junctions; 3) largest gain-bandwidth product in avalanche diodes. ALTHOUGH the total number of materials exhibiting photoconductivity effects is very large, only a relatively few of these have appropriate properties for a practical photoelectronic radiation detector. In fact if one surveys the commercial detectors currently available, one finds that the field is dominated by some ten or fewer materials. These are summarized in Table 1 in terms of the other important variable in detector fabrication, the structure of the material, i.e., whether the material is used as a single crystal or in polycrystalline form, and whether the material is used as a homogeneous detector or whether the detector depends upon the existence of a junction or barrier in the material. The principal wavelength range for each type of material is also shown, together with an indication of the utilization of intrinsic or extrinsic excitation. For the purposes of the present comparison of various detectors, it will be convenient to discuss two main topics: homogeneous photodetectors and junction photodetectors. The performance of a photoelectronic radiation detector is measured in terms of two parameters: the photoconductivity gain, and the response time of the detector. A convenient figure-of-merit is given by the ratio of gain to response time, often called the gain-bandwidth product. The photoconductivity gain is a device parameter since it varies in many cases with the applied voltage and the detector geometry, and should be distinguished from the actual photosensitivity of the material involved. This photosensitivity can be conveniently given as the product of free carrier lifetime and mobility in the material. The photoconductivity gain is defined as the number of charge carriers which pass between the electrodes per second for each photon absorbed per second, where G is the photoconductivity gain, is the pho-tocurrent in amperes, e is the electronic charge in coulombs, and F is the total number of electron-hole pairs created in the photo conductor per second by the absorption of light. The gain may also be expressed as the ratio of the lifetime of a free carrier to the transit time for that carrier, i.e., the time required for the carrier to move between the electrodes. For a material in which one-carrier conductivity dominates, where T is the lifetime of a free carrier, ttr is the transit time for this carrier, p is the carrier mobil-ity, V is the applied voltage, and L is the electrode spacing. From Eq. [2] it follows that the photoconductivity gain is proportional to the photosensitivity of the material (tP), the proportionality constant being The photosensitivity of a material, and hence the photoconductivity gain of a device utilizing the material, depends on the lifetime of the free carriers as a critical parameter. In a homogeneous material this lifetime is determined by the nature of imperfections in the material, and in an inhomogeneous material the lifetime is determined by the specific junction structure. The speed of response, the other basic photodetec-tor parameter, is determined by factors quite similar to those important for photoconductivity gain. Imperfections are of primary importance in homogeneous materials, and the structure of the junction is a determining factor in junction devices. For infrared detectors it has become common to define another quantity designed to indicate directly how effective the detector is in distinguishing between a small photoconductivity signal and random noise due to the detector and its environment. The detectivity D* is given by

Jan 1, 1968

By Craig R. Barreft, Oleg D. Sherby

The steady-state creep characteristics of pure polycrystalline copper were studied in the temperature range 400" to 950°C and in the stress range 400 to 7000 psi. Tests were conducted in dry deoxidized hydrogen and all specimens exhibited high ductility before fracture. Two activation energies for creep were established as a function of temperature. Above about T/T, = 0.65, the activation energy for creep was 48,000 cal per mole whereas between 0.5 and 0.65 T, it was 28,000 cal per mole. The observed temperature dependence of the activation energy for creep follows the same trend as exhibited by the self-diffusion coefficient of copper in copper single crystals and silver in silver single crystals. It is therefore believed that the rate-cmtrolling mechanism in creep of copper in the stress and temperature range studied is diffusion-dependent and is probably associated with a dislocation-climb process. The low activation-energy region is attributed to enhanced volume difFusion from the presence of dislocations which act as short-circuit paths for diffusion. THERE is extensive experimental evidence1,2 that the activation energy for creep, Q,, for pure poly-crystalline metals tested at temperatures above one half the absolute melting temperature (0.5 Tm) is a constant and equal to the activation energy for volume self-diffusion, Qsd This equality is generally interpreted as meaning that creep in this temperature range is controlled by a dislocation-climb process. The existence of high-temperature creep activation energies not equal to the respective self-diffusion values has been suggested both theoretically3"5 and experimentally.6-8 Two examples of apparent nonequality between Q, and Qsd have been reported for the cases of silver7 and copper,' where activation energies for creep much lower than those for self-diffusion persist to rela- tively high temperatures (up to 0.6 T,). These observations suggest that dislocation climb may not be the only important process in the high-temperature deformation of these metals. That dislocation climb does indeed occur relatively slowly in these two metals due to their low stacking-fault energy has been suggested by many investigators.9-10 Although the creep behavior of copper has been studied extensively at low temperatures, the high-temperature activation energy for creep is not well-defined. The data of Feltham and Meakin8 indicated that Q, is temperature-dependent above one half the melting temperature, equaling a value of -30,000 cal per mole at temperatures up to 550°C and increasing to a value of -49,000 cal per mole at 700°C. No data has been reported above 700°C. The value of 49,000 cal per mole is very near the value of Qsd for copper reported by Kuper et al." as 47,100 cal per mole. In view of the lack of high-temperature creep data and the apparent temperature dependence of Q, for copper the present investigation was undertaken to determine the value of Q, over the temperature range of 400" to 950°C. It was hoped that such a study would clearly document the temperature dependence of Q, and yield significant information as to the nature of the rate-controlling creep mechanisms. MATERIALS AND PROCEDURES The material used in this investigation was high-purity OFHC copper. After rolling and recrystal-lization treatments spectrographic and chemical analyses showed only 0.0008 pct Ag, 0.0002 pctCa, 0.0002 pct H2, and 0.002 pct O2 as trace impurities indicating a purity of greater then 99.995 pct. Specimens were machined from cold-rolled sheet and the gage sections polished with 2/0 emery paper prior to annealing treatments. Annealing was done in both vacuum and dry deoxidized hydrogen atmospheres. No variation in creep strength was found as a result of the different annealing atmospheres. The final annealing temperature was either 700°, 800°, or 1000°C depending on the temperature range to be studied. These treatments resulted in average grain diameters of 0.03, 0.4, and 1.0 mm, respectively. The precise mechanical-thermal history of these

Jan 1, 1964

By H. T. Shore, J. M. Schultz

A number of experimental rnethods—X-ray powder diffractometry, Laue photography, X-ray small-angle scattering, and transmission electron microscopy and dijfraction—have been utilized to examine the morphology associated with precipitation from the terminal, g, solid solution of a Zn-1 pct Cu alloy. A significant age hardening was observed in a 1 pct Cu alloy. X-ray and electron diffraction results showed that the structural inhomogeneities associated with the hardening were isotructural with the matrix. The average size and shape of the inhomogeneities were deduced from the electron microscopy and X-ray small-angle scattering. The preprecipitates are hexagonal platelets some 300? in diam. and some twelve unit cells thick. The orientation of the platelets was deduced from Laue photographs and electron diffraction. The platelet plane is (0001). When a large amount of pre-precipitation is present in a localized volume the new lattice is often disoriented by a rotation about (0001) of of the matrix. WhILE dilute Zn-Cu alloys have been commercially important for some 50 years, relatively very little is known metallographically about this material. The "Zilloys", zinc with about 1 wt pct Cu and sometimes a small addition of magnesium, are used to produce rolled zinc which is harder and stronger than that produced by other rollable zinc alloys.' According to the phase diagrams of the zinc-rich side of the Cu-Zn system, such dilute Zn-Cu alloys should age-harden;2-5 the solubility of copper in zinc, g-phase, at 424°C is 2.68 pct, while at 0°C it is only to 0.3 pct. However, the published literature on the aging of this system appears to be limited to a documentation of the contraction of 1, 2, and 3 pct Cu alloys aging at 95°c,6 and an attempt to measure changes in lattice parameters during aging.' In the latter work, no lattice parameter changes were detected, although a broadening of the highest-angle lines was detected and considerable diffuse scattering was observed. Micro-structural investigations have been limited to the latest stage of aging, wherein Widmanstatten precipitates are formed.3,47 These alloys are of interest for still another reason. The two most zinc-rich phases in the Cu-Zn system, 77 and E, are both hcp. Moreover, the change in a, between 17 and t for a 1 wt pct Cu alloy is onlv 3.64 -,~ct: the change in Co is 12.0 ict. It would be anticipated that precipitation in such a material might occur through metastable phases or G.P. zones with epitaxy along mutual 0001 planes. The goals of the present work are aimed at partially filling the void of knowledge concerning the early stages of precipitation from the g phase. In particular, we have attempted to document the magnitude of the age hardening of this system and to determine the size, shape, and orientation within the matrix of the elements of precipitation in an early stage of condensation. EXPERIMENTAL A) Specimen Preparation. Specimens were prepared In two somewhat different ways, one method being used for X-ray Laue and diffractometer measurements, optical microscopy, and Rockwell hardness measurements and the other used for electron microscopy and X-ray small-angle scattering. In the first case zinc and copper in the proper proportions to yield a 1 wt pct Cu alloy were melted together in a closed graphite crucible. Castings so made were free of apparent segregation or oxidation. The castings were then solution-annealed at 400°C for several days and then quenched in water to room temperature. Filings of portions of the specimens were made for use as X-ray powder diffractometry specimens. The electron microscope material was made as follows. Castings were made under vacuum with copper powder placed inside a hollow zinc cylinder to insure good contact of the materials. These 1 wt pct Cu pieces were then rolled to 0.1 mm with an intermediate anneal in vacuo. The rolled sheets so formed were then annealed for about 6 hr at 225°C. Finally the specimens were electropolished slowly until thin enough for transmission electron microscopy. The polishing is discussed in greater detail in the Results section. B) Measurements. X-ray measurements of three types were performed. A G.E. XRD-5 diffractometer was used to examine powders of the alloy for identification of second-phase material. A Kratky small-angle camera, also operating from a G.E. tube, was used to investigate the sizes of small precipitate particles. In both cases, nickel-filtered copper radiation was utilized. Finally, individual grains of the large-grained castings were examined in the back-reflection Laue geometry. Electron microscope studies were carried out with a J.E.O.L. Model 6A instrument. RESULTS A) Hardness Measurements. Hardness measurements performed at room temperature on the large-grained polycrystalline specimens showed a hardening which was essentially complete in 3 hr. Fig. 1 shows a typical plot of hardness vs aging time. The relative magnitude of the ultimate hardening varied from run to run between 150 and 200 pct of the value for the material immediately after quenching from the solution anneal. Most probably the variations reflect small changes in the time taken to remove the specimen from the vacuum furnace after the solution anneal.

Jan 1, 1969

By J. Wesley Pullman

It is stated by Dr. Tuttle in a paper read before the New Jersey Historical Society, that the celebrated Dickerson mine at Succasunna, Morris Co., N. J., yielded ore, about as early as 1710, for use at the Whippany forge, on Rockaway River, between Rockaway and Boonton. The ore was, for some time, free to all who chose to dig it. The tract embracing the Dickerson mine mas taken up, on account of its minerals, in 1713 or 1714, by John Reading, who sold it in 1716 to Joseph Kirkbride. John Jackson built a forge in 1722 on the Rockaway River a mile west of Dover. The ore here worked was probably chiefly from the Dickerson mine, but a portion may have been Hibernia. Hon. E. D. Halsey, of Rockaway, K. J., writes me: It is quite possible that the ore was at first taken from the outcrop of Hibernia by anybody who wanted it. The property first had an owner, May

Jan 1, 1886

By J. H. Nead, T. S. Washburn

The grades of commercial steel produced in large quantities can be divided into two general types from the standpoint of ingot structure— killed and rimmed. Killed steel covers a wide variety with carbon contents throughout the range of the steel portion of the iron-carbon diagram, and is the kind usually used in the production of alloy steels. Rimmed steel is normally associated with carbon ranges under 0.30 per cent, and is not yet used to a large extent in alloy practice, except for copper-bearing steels. The fundamental differences in the ingots made from these two types of steel can be seen most easily in Figs. 1 to 7. In the rimmed ingot shown in Figs. 5 to 7 there are two lines of blowholes approximately parallel to the sides and coming together at the top and at the bottom of the ingot. In the killed ingots shown in Figs. 1 to 4 these blowholes arc not present. Also, the rimmed ingot has no well defined pipe, as compared to the deep pipe on the killed ingots, and there are numerous primary blowholes in the lower portion of the rimmed ingot perpendicular to the surface and close to it, while on the killed ingot there are no blowholes of this type in the ingot shown in Fig. 1 and very small ones close to the surface in the lower part of the ingot shown in Figs. 2 to 4. With respect to the presence of pipe and the primary blowholes, the structure may vary considerably in both rimmed and killed ingots, therefore these cannot be considered as fundamental structural characteristics differentiating the two types of steel. The primary blowholes in rimmed ingots may be much less pronounced than those in the ingot shown in Figs. 5 to 7—as, for example, in "ingot iron," which is entirely free from them. An example of a cross section of an ingot-iron ingot is shown on page 16 of "Research and Methods of Analysis of Iron and Steel," published by the American Rolling Mill Co. (1920). A certain amount of pipe may also occur in rimmed ingots, though it is normally porous and not as well defined [or deep as in the killed ingot of Fig. 1. In killed ingots, primary blowholes may occur near the surface, as in Figs. 2 to 4, and

Jan 1, 1937

By C. S. Barrett, O. R. Trautz

PREVIOUS investigations have shown that lithium is body-centered cubic from near its melting point to the temperature of liquid air1,2,3 Nevertheless there was an incentive to search again for a transformation at low temperatures: C. Zener4,5 has remarked that the low value of the elastic modulus (11 - C12)/2 of body-centered cubic metals and alloys implies a rapid increase in free energy with decreasing temperature, which would favor the occurrence of a transformation; also the shear movement to which this modulus applies is one that can transform a body-centered cubic structure into a slightly distorted face-centered cubic structure. It was confirmed that lithium does not transform spontaneously at liquid nitrogen temperature, but it was found that a transformation can be induced at this temperature by cold working the metal,6 and at slightly lower temperatures a different transformation occurs spontaneously. Transformations were also found in solid solutions of magnesium in lithium. THE NATURE OF THE TRANSFORMATIONS Before presenting a detailed treatment of the technique used and the specific data obtained, it would be well to give a brief survey of the general characteristics of the transformations. A new crystal structure begins to form spontaneously in a specimen when it is cooled below a critical temperature. In lithium the structure appears to be close-packed hexagonal; in the Li-Mg alloys most of the diffraction lines (but not all) are near those for hexagonal lithium. The transformation proceeds as the temperature is lowered and soon stops if the temperature is held constant or raised. The course of the transformation on cooling is indicated by the curve at the lower left of Fig I. This curve is drawn in stepped fashion because the transformation goes by discrete steps with audible clicks. Because of the similarity to the decomposition of austenite into martensite in steels, it seems appropriate to designate the beginning of the spontaneous transformation on cooling as the Ms point. On heating to room temperature after the low temperature treatment only the usual BCC structure is found. On heating, the low temperature modification begins to disappear at a temperature which will be designated as Ac. The transformation on heating is halted when the rise in temperature is halted. The temperature must be raised 40 to 50°C above Ac before the reversion is complete-an interval which is sensitive to the rate of heating and to the time of holding at temperatures above Ac. This behavior on heating thus has similarities also to the formation of martensite in the cooling of steels.

Jan 1, 1948

By AIME AIME

MODERN metallurgy is an art and a science. The art is process metallurgy-extracting metals from their ores, refining them, and alloying them with one another and with certain nonmetals to produce thereby a variety of metallic materials which, owing to a wide range of useful properties, are for many purposes more valuable to man than the individual metals themselves; process metallurgy also includes shaping or otherwise treating metals and alloys to form objects useful to a complex industrial world. The science is physical metallurgy-organized knowledge of the constitution and internal structure of metals and alloys, of the relation of their composition and structure to properties, and of the laws, theories, and hypotheses that purport to explain this relation.

Jan 1, 1942

By Carel Robinson

MECHANIZATION of coal mine, is radically changing the requirements for under-ground transportation. It has increased materially the need for reliability and belt conveyors are the most dependable means of moving coal away from the place where it is mined. Their record of freedom from delays is almost 100 per cent. Why then are- not belt conveyors in more general use. Part of the answer lies in the pour records made at some of the earlier installations, and in the fact that belts have so long been identified as a type of equipment suitable, in the main, only to thin seams. Another reason is lack of knowledge of the full potentialities of belt transportation.

Jan 1, 1941

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 Lurmann 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 Glasgom 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

Jan 1, 1907

By Benjamin F. Tillson

The hammer drill rightly receives the credit for having made the one-man drill possible, and so many economies seem possible through the proper application of different types of hammer drills to various mining, quarrying, and excavating operations, that an indication of the 'economies effected by the New Jersey Zinc Co. at its Franklin mines may be of pertinent interest. When this company commenced its trials of hammer drills in 1907, these tools had not been developed to one-fourth the capacity and refinement which they have at present. At that time it was frequently stated that such a small tool, drilling holes of less diameter than the reciprocating rock drill, could not drill enough holes in a shift to permit the placing of sufficient explosive to break a tonnage of ore comparable with that produced by the "rock drills;" that the placing of small holes inclined upward, at angles steeper than 40' above the horizontal, could not be expected to produce results equal to the large flat, wet or dry, holes in the breasted back of an overhand stope, and would only shatter the ground so as to make the back unsafe. In spite of these adverse opinions, the hammer drills first showed their superiority over both heavy and light reciprocating drills in raising and in stoping, and then in drifting and quarry work. As a result, all of the reciprocating drills at the Franklin mines were scrapped three years ago, all of the mining work being accomplished with increased efficiency, as shown in detail in this article. With the advent of the hammer drill in this property, it was considered advisable to make comparative tests of all the tools accessible, and it has since been the policy to investigate the merits of any advance of the drilling art in order to get the maximum amount of work from the tools. The necessity of devising some means of standardizing drill tests, and of measuring the consumption of compressed air as well as the drilling speed, was early realized. The common test was to fill a measured air receiver with compressed air at a certain gauge pressure, run the drill until the pressure had dropped to too low a figure, then compute from the time, drop in pressure, and

Jan 1, 1915