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By K. D. Sheffler, R. W. Hertzberg, R. W. Kraft

The Ni-Ni,Ti lamellar eutectic alloy responds to unidirectional solidification by alig-nment of the platelets of the two phases roilghly perpendicular to the moving solid-liquid interface. X-ray diffraction and zetallographic experimenls show that the following cryslallographic relationships exist in the directionally solidified ingots: lamellar interface w [0001] Ni3Ti 11 (111 }Ni local growth direction (1120) Ni3Ti n (110) Ni These relationships are rationalized on the basis of the crystallography of the constituent phases. In recent years researchers in several laboratories have shown that an aligned or "controlled" micro-structure can be produced in many binary eutectic alloys by forcing the alloy to solidify unidirectionally in an elongated crucible.'-3 It also has been found that a unique crystallographic relationship often develops between the two phases in such a structure.4, 5 Since a parallel arrangement of phase particles in an alloy should, and, in many cases, does, produce unique and highly anisotropic properties, the alloys so produced are of potential interest in a variety of applications. Studies of these alloys are also of interest at the academic level because they help to improve our basic understanding of the way in which metals solidify. This paper reports the metallographic and crystallographic structure of another of these alloys—that between nickel and Ni3Ti. In a separate paper, hot tensile and stress rupture properties as well as deformation and fracture behavior of the same alloy are discussed.19 EXPERIMENTAL DETAILS AND RESULTS General Characteristics of the Eutectic Reaction. Several small exploratory Ni-Ti melts were made to resolve a conflict in Hansen6 over the eutectic composition. The alloy containing 16.4 at. pct Ti, Fig. 1, appeared metallographically to be closest to the eutectic composition, although small dendritic patches of proeutectic nickel are present. The eutectic morphology is lamellar and appears quite sharp and angular, indicating a strong influence of crystallographic factors upon the microstructure. Some of the eutectic nickel platelets are continuous with the primary phase, whereas in hyper eutectic melts a "halo" of nickel generally surrounded the proeutectic inter-metallic platelets, indicating that nickel is the nucleating phase in this eutectic reaction. Extensive precipitation of Ni3Ti has occurred in the primary nickel phase in a Widmanstatten pattern which makes the dendrites difficult to differentiate from the eutectic mixture. This phenomenon may account for discrepancies among the eutectic compositions reported in the literature. The sloping solvus line bounding the nickel primary solid solution explains the presence of the intermetallic precipitate. Poole and Hume-Rothery7 report that the solubility of titanium in nickel drops from 13.8 at. pct at the eutectic temperature (1304°C) to approximately 9 at. pct at 700°C (Ni3Ti, on the other hand, melts con-gruently and exhibits essentially no solubility for nickel or titanium). Lever rule calculations based upon Poole and Hume-Rothery's phase diagram indicate an increase from 21 vol pct Ni3Ti in the eutectic mixture at the eutectic temperature to 61 pct at room temperature. Selective point count measurements of the volume fraction of eutectic Ni3Ti platelets in the eutectic microstructure yielded a value of 46 i 2 vol pct, which required extensive precipitation of Ni3Ti from the nickel solid solution onto the eutectic intermetallic platelets during cooling from the solidification temperature. Influence of Directional Solidification. Nickel bar and titanium sponge of 99.9 pct purity were induction-melted in zirconia crucibles under argon in the proportion of 13.8 wt pct (16.4 at. pct) Ti to produce 14-lb master heats which were cast into investment molds yielding 5/8-in.-diam pins approximately 10 in. long. These pins were remelted under argon in horizontal zirconia boats and unidirectionally solidified to produce 1/2-in.-sq ingots approximately 44 in. long. Details of the experimental techniques and apparatus are described elsewhere.'

Jan 1, 1970

In the General Alphabetical and Analytical Index of A I M E Publications for the years 1926 through 1935, a complete list of the volumes covered is printed on page 5, but the dates of publication of the volumes are not given Therefore the following information regarding the volumes that were printed without numbers may be useful to users of the Index

Jan 1, 1937

By Atmaram H. Soni

A statistical study of machinability led the writer to examine existing data in regard to a thermal conductivity-mechanical properties relationship. Various functional relationships were proposed and the multiple correlation determined by statistical methods discussed in detail in the 1iterature.4 The relationship having the greatest engineering and statistical significance is discussed below. The data for cast and wrought aluminum alloys''2 have been compiled and analyzed separately. The results of these analyses are presented in Table I. The empirical equations for estimating the thermal conductivity (cal sec-' cm-I °C) are: for cast aluminum alloys K = 0.584 -0.00984/ -0.00263 Hb [1] and for wrought aluminum alloys K = 0.604 -0.00424l- 0.00170 Hb [2] where 1 and Hb are the percentage elongation and Brinell hardness number. Results of a similar analysis pertaining to stainless steel3 are also given in Table I. This empirical equation for estimating thermal conductivity (Btu per sq ft per hr per °F per in.) is K = 216.19- 1.716l - 0.0997 Hb [3] The relationship between electrical resistivity and mechanical properties was also examined for aluminum alloys using the same statistical method. These results are listed in Table II. While the situation of exact multiple correlation

Jan 1, 1965

By C. G. Dunn

With respect to theories of recrystalliza-tion in metals plastically deformed. it has been said that the present status of this subject is far from satisfactory.1 It may also be said that before any mechanism of recrystallization for metals and alloys can be set forth in a satisfactory manner, there must be made available considerable data on orientation changes that occur during the deformation and recrystallization processes. Although extensive data have been published on recrystallization in single crystals and in poly-crystalline specimens, more results of a type that can be classified according to simple orientation changes would be desirable in this complex field. It might even be said that before classifications are made according to types of orientation changes, it may be possible to classify a considerable amount of data into certain kinds of orientation states if groups of common or nearly common orientation occur. Methods for computing the probability of occurrence for various types of groups have been published2 and it has been pointed out in particular that it should be possible to analyze orientation data for high-order twin relationships between old and new grains even when agreement is not at all exact. In this connection, work on recrystallization in silicon ferrite reported in a paper concerned with complex groups of annealing twins3 indicated that some data were consistent with primary nucleation OCcurring according to a second-order or a third-order twin transformation. However, further work in this latter direction was definitely needed. It is, therefore, the purpose of the present paper to report data and analyses for primary nucleation in silicon ferrite following small deformations that have been carried Out at the Pittsfield Works' Laboratory of the General Electric Co. Analyses have been made with the aid of standard groups of twins that are reported elsewhere.4 PReparation oF Specimens and Experimental Procedure The material used in the present investigation was taken from the same heat of steel as that .used in a prior report.3 The finished strip in both cases was made by the Allegheny-Ludlum Steel Corporation according to methods that produce a high degree of preferred crystal orientation. Samples with large grains had the following composition: 3.45 per cent Si, 0.003 C, 0.008 P, 0.020 S, 0,075 Mn, 0.03I A1 and 0.072 Cu. Thickness of specimens was 0.012 inches. Plastic deformation was produced by cold-rolling the samples on a mill with 8-in. diameter rolls, the plane of the sample in each case coinciding with an XY plane (the plane of projection for the stereo-graphic plots) and the elongation occurring in the X direction. In general, elongations were held to about 3 or 4 per cent.

Jan 1, 1945

(The following list contains the names of those members of the Institute of whose connection with military service we have only recently become acquainted; it also includes the names of a few who have recently been promoted or transferred, indicated by a *. A complete list was published in the Year Book, issued as a supplement of the Bulletin for March, 1918.) ALLEN, Roy H., Capt., Air Service, Bureau of Aircraft Production, Washington, D. C. *AMIDON, CLAUDE E., Chemical Warfare Section', Astoria, L. I. *ARCHBALD, HUGH, 311th Infantry, 78th Division, American E. F. ASKIN, THOMAS B. H., Radio Station, Cavite, P. I. *AYER, FRANK A., Lieut., Commanding Officer, -270th Aero Squadron, American E. F. BARBA, W. P., Lieut. Colonel, Ordnance, U. S. A., Washington, D. C. *BARRETT, LESLIE P., 1st Lieut., 5th Field Artillery, American E. F. BLICKENSDERFER, F. C., 1st Lieut., N. A., Ordnance Dept., Edgewood Arsenal, Edgewood, Md. *BROOKS, FLOYD R.., Lieut., Canadian Engineers, Seaford, England. BROWN, GEORGE M., Co. G, 1st Replacement Regiment, Washington Barracks, D. C. *BRUNEL, LOUIS J., Lieut., 5th Field Artillery, Brigade Headquarters, American E. F. *BRUNTON, D. W., Cons. Engr., Naval Consulting Board, Washington, D. C.

Jan 11, 1918

By R. P. Rothwell

THE first difficulty mentioned is that in some instances two or more beds of coal separated by sandstone or slate rocks of considerable thickness in one part of a basin, are found running together in another part. Of course, we may happen to strike first the part of the basin where there is but a single seam, and in this case the bed would appear to divide into two or more branches within a short distance. Such cases are not rare in the anthracite coal-fields. I would suggest as an explanation of this phenomenon the gradual sinking of the peat-marsh-the embryo coal-bed-on one side, and the moving forward of the marsh, so that on one part of the bed the formation of peat would still be progressing, while another part, being under water, would be covered with mud and sand. Thus we have different portions of the same bed of different ages. Now if the sinking of the marsh be stopped for a time, the bed will become thicker in the portions left exposed, and if the sinking now changes in direction, so that the part that had previously gone down com¬mences to rise, we should have the phenomenon of a bed, continuous throughout, with one portion overlying another, and separated from it by rock strata. These are exactly the conditions observed in splitting beds. While one side of the lake is sinking, and the peat-marsh moving on in that direction, the other side may be rising,

Jan 1, 1873

ALABAMA Aldrich.-Lloyd, T W Anniston.-Carrington, F G Gerber, A B Heimrod, A A. White, H E Ashland.-Barton, J C Sturdevant, J C Bessemer.-Abbott, C E Ball, T L Hines, H K Hodgkin, W -0. Salmon, H S Thompson, N E Birmingham.-Adams, J H Adler, J. E Aldrich, T H Aldrich, T H, Jr. Ball, E M

Jan 1, 1923

ALABAMA Aldrich.-Lloyd, T. W. Anniston.-Carrington, F. G. Klugh, B. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson V. Salmon, h. S. Stuart, Q. W. Birmingham.-Adams, J. H. Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Armstrong. W. D. Ball, E. M. Bonnyman, J. Bush, M. W. Carter, E. Crawford, G. G. Davis, C. B. Dryer. T. B.

Jan 1, 1923

ALABAMA Auburn.-Brown, R. L. Battelle.-Green, G. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson, V. Birmingham.-Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Bonnyman, J. Bowron, J. Crawford, G. G. Crockard, F. H. Ellis, E. E. Fairbairn, C. T. Gambrill, G. T., Jr. Geismer, H. S. Hiller, E. McCormack, G. B. Maben, J. C.

Jan 1, 1917

By C. Bezemer, I. Havenaar

An investigation was carried out on the dynamic liltration behavior of drilling fluids. In a set-up consisting of a porous pipe through which the drilling mud was circulated, dynamic liltration rates and cake thicknesses were determined as a function of flow rate and filtration time. Eventually, a state of equilibrium was reached; i.e., both cake thickness and filtration rate attained constant values. Concurrently, dynamic filtration tests were carried out in a simple dynamic filter apparatus where mud flow was similar to that in a rotational vismmeter. In both arrangements the relation between equilibrium liltration data and rate of shear at the cake surlace was studied. Filter pipe and dynamic filter apparatus were lound to give identical relations. It was therelore concluded that the latter apparatus, which is suitable lor routine measurements on small amounts of mud, could be used to determine the dynamic liltration behavior of mud under borehole flow conditions. Some data are presented on the effect of filtration pressure and temperature on equilibrium filtration rate and cake thickness. INTRODUCTION In oil well drilling, the drilling fluid used generally forms a mud cake on the permeable sections of the borehole wall while filtrate is lost into the formation. As to the conditions under which this filtration process takes place, a distinction should be made between static mud filtration (mud is not circulating) and dynamic mud filtration (mud is circulating). In recent years several investigatorsl-5 have studied the process of dynamic mud filtration about which little had previously been known. This type of filtration is the subject of this paper which confirms several findings of previous investigators. It differs from already published works, however, in the following respects. 1. It contains a description of a simple laboratory apparatus developed for dynamic filtration measurements on small amounts of mud. 2. The effect of rate of shear at the cake surface on dynamic filtration has been studied. As a result of this study, dynamic filtration data pertaining to the borehole conditions of mud flow can be found from laboratory tests. 3. Some data are presented on the effect of filtration pressure and temperature on dynamic filtration. The work was limited to a small number of muds. No attempt was made to compare data on API filtrare loss with dynamic filtration rates. Previous workers have clearly shown that no correlation exists between static and dynamic filtration rates. EXPERIMENTAL ARRANGEMENT To establish whether the effect of mud flow conditions on dynamic filtrations is governed by the rate of shear at the cake surface, two different types of mud flow were used. In this connection the experiments were partially conducted by means of a porous pipe through which mud was circulated, partly in a dynamic filter apparatus which somewhat resembles a rotational viscometer. In both cases the flow conditions of the mud were well defined, thus making it possible to-calculate rates of shear at the cake surface. The filter pipe was 200 cm long with an internal diameter of 3 cm. Its perforated wall was covered on the inside with filter cloth on which the mud cake could form. Mud was pumped through the pipe at linear rates varying from 20 to 186 cm/sec. The required filtration pressure was obtained by means of a lack-pressure valve downstream of the filter pipe. In this arrangement the type of flow existing in the borehole is reasonably well simulated. The dynamic filter apparatus (Figs. I. and 2) consists mainly of two concentric cylinders with a clearance of about 0.5 cm. The outer cylinder (rotor) can be rotated at rates up to 1,000 rpm. The outer surface of the inner cylinder (radius about 2.5 cm) is covered with filter cloth or paper supported by copper gauze. The two cylinders are mounted inside a pressure

Jan 1, 1967

By Å. Sterten, R. Tunold, J. Brun, K. Dalatun

The subjects of this study are two corrosion phenomena familiar to operators of aluminum plants employing Soderberg anodes of the vertical type, namely the sul-fide scale formation observed at the steel contact spikes and the corrosion wear observed at the lower edge of the gas collecting skirts. The causes of these corrosion phenomena are discussed on the basis of observations from practice and measurements on commercial cells as well as on laboratory experiments. It is concluded that the anode spike corrosion is mainly due to the attack by sulfur compounds contained in the anodically evolved gases and that this attack is greatly promoted by cracks and pores in the anode carbon embedding the lower spike ends. The corrosion of the gas collecting skirt is mainly attributed to anodic dissolution of the iron during occasional contacts with the melt. ANODE SPIKE CORROSION The visible result of this corrosion is the formation of a brittle loosely adherent scale on the lower ends of the mild steel spikes maintaining the electric contact to the carbon anode, Fig. 1. The thickness of the scale usually varies from 0.5 to 3 mm, but in some cases scale of about 10 mm thickness has been observed by the writers. During the spike pulling, usually repeated every 3 weeks, part of the scale often loosens and remains in the anode carbon, resulting in contamination of the aluminum with iron. This corrosion has been attributed to reaction of the iron with gaseous sulfur compounds originating from the anode paste materials.'-4 This paste usually consists of 70 pct precalcined petroleum coke with 1.2 to 1.4 pct S and 30 pct coal tar pitch containing 0.5 to 0.7 pct S. During operation the gasification of the anode materials takes place in two ways: First, gases are evolved by the gradual baking of the anode paste added on top of the anode. Due to the sealing effected by the upper semifluid zone of the paste, these gases, containing sulfur compounds from the pitch, are forced downward through pores and cracks in the rigid anode carbon. At the temperatures of the zone of the lower ends of the spikes, 700" to 900°C, the original components of the baking gas must undergo decomposition, similar to that taking place with the production of coal gas, resulting in a gas mixture consisting mainly of H2 and CH4 with small percentages of H2S as the main sulfur compound.5 Second, the anodic reaction results in a mixture of C02 and CO, the total quantity of which is about 15 times that of the baking gas. These anode gases must carry the entire sulfur content of the carbon gasified by the anodic reaction. Henry and Holliday6 have shown that COS is the main sulfurous component of the anode gases from Soderberg cells. Soderberg anodes usually exhibit a network of vertical cracks, frequently traversing from one spike to the next one and to the outside of the block and widening downward to the working face of the anode. In addition the anode carbon, particularly that below the spike ends, is rather porous, as indicated in Fig. 1. It therefore seems probable that the anode gases also may partly penetrate to the spike ends. As the anode is partly immersed in the melt, the static pressure of this must forward this penetration. I) SPIKE SCALE COMPOSITION A great number of freshly extracted spikes from industrial plants were inspected and samples of the scale collected for examination. Before analyzing the samples a thin iron oxide layer, formed by air oxidation of the outside of the red hot scale immediately after spike pulling, was removed. On the average the Fe/S ratio found by these analyses corresponded to I the composition FeSl. oo7. X-ray powder patterns showed no oxide and otherwise agreed with those found by Haraldsen7 for iron sulfide with 50.00 at. Pct

Jan 1, 1970

By Edward C. Morse

The metallurgical history of Republic has been completely reviewed in a paper presented at a previous meeting of the Spokane Local Section by Professor Thomson;' therefore, the present paper will be confined to matters directly pertaining to the San Poil mill: When I came to Republic last fall to look over the situation there was a plant in operation successfully treating the tailings from one of the earlier mills in the camp. I refer to the mill of the Rathfon Reduction Co. This mill was operating in accordance with modern cyaniding practice, and I was given to understand that the work was very satisfactory and profitable, else it would not have been continued as long as it was. At that time I obtained much metallurgical information of value from Harry W. Newton, Superintendent of the mill of the North Washington Power & Reduction Co. I took a number of samples from the San Poil mine, with the view of determining if Mr. Newton's experience with the ores from the other mines applied to the San Poil ores. I made a large number of tests under a variety of conditions, and found that it was possible to extract as high as 98 per cent, of the values from San Poil ore by the laboratory-tests when the ore was pulverized to 200-mesh and treated with a solution of a strength of 5 Ib. of KCN to the ton. A fairly strong solution was required because of the proportion of silver in the ore, which makes it, from a metallurgical point of view, practically

Jan 1, 1913

By Edgar M. Dunn

Part I. Determination oF Gases in Smelter Flues. General considerations. Regular methods for carbon monoxide, oxygen, nitrogen, moisture. Sulphur oxides-—Methods of Lunge and Hempel tried, and either modified or discarded, with reasons therefor. Gravimetric method developed at Anaconda. Description of apparatus used. Brief notes on Richter and Hawley methods for the direct cietermination of sulphur trioxide. Carbon dioxide, with complete notes on same. Arsenic trioxide. Table of percentages of flue gas constituents found at a Western smelter. Some final notations as to the value of flue gas analysis, in connection with an intelligent log of furnace operations. Part II. Notes on the Determination oF Dust Losses at the Washoe Reduction Works, Anaconda, Mont. Discussion of problem, with description of flue system. Various places and methods for determinations of velocity. Instruments used. Procedure in making determinations for velocity. Soundings of cross-section for depths of dust. Calculation of velocities and areas. Daily volume of gas, and plant operations during tests. Place for dust determinations. Apparatus and methods of 'sampling. Results obtained, with table of daily amount of dust losses. Analysis of dusts for values, from various sampling stations. Complete analysis of composite sample of stack emanation. Last analysis totaled to show form in which present. Discussion of recovery as a commercial proposition. References on Pitot tube and calculations.

Jan 1, 1914

By V. Balasubarmanian, Rajendra Kumar

ISOTHERMAL formation of martensite in a copper-aluminum-nickel alloy was previously reported by Hull and Garwood.' In the present work an attempt has been made to investigate some of the character- istics of the formation of isothermal martensite in binary copper-aluminum alloys containing 14.00 and 14.50 pct Al, respectively. Chill-cast alloys were prepared from OFHC copper and aluminum of greater than 99.5 pct purity. They were homogenized for 24 hr at 950° C. Polished samples were soaked at 1000°C and quenched in water to retain the p phase untransformed; martensite did not form during the quench. The surface was then repolished for isothermal microscopic studies at room temperature. The salient features of the martensitic transformation in copper-aluminum alloys observed in this investigation are: a) The transformation progresses (i) by nuclea-tion at new sites and (ii) by simultaneous slow isothermal growth of existing martensite plates. Slow isothermal growth of martensite has previously been observed by Holden2 in an uranium-chromium alloy and by Hull and Garwood in copper-aluminum-nickel alloy. b) Martensite plates nucleate preferentially at the pin holes formed during the casting of the specimen, Fig. 1. c) Some of the martensite plates pass right through other plates lying in their path, Fig. 1. d) Martensite plates cross grain boundaries without any change in the direction of growth. e) An irregular network of markings, Fig. 2, appears simultaneously with the formation of martensite. It was less prominent in the case of 14.5 pct alloy. The markings may arise due to spontaneous deformation under the lattice strains of the martensitic transformation. Crossing of martensite plates was first observed by Kulin and cohen3 when a high-nickel steel was cooled to 77°K. They suggested that the rapidly advancing plates atquire considerable kinetic energy and strike the obstructing plate with a momentum so as to nucleate the process on the other side of the plate. This, however, fails to explain the present observation where the slow isothermally growing martensite plates cross each other. Such plates would not possess large momentum to bodily displace the obstructing plate. Fig. 1 shows the martensite plates crossing each other without body displacements. This should be contrasted with Fig. 3 of Kulin and Cohen's paper where crossing of plates is accompanied by shearing or body displacements of the plates. The present observations can, how-

Jan 1, 1961

By Robert N. McIndoo

A good tire program must begin at the top; management must have an awareness of the tremendous potential for cost saving that tires represent. At Reserve Mining Co., tires account for 33% of the cost of maintaining its 44 tractor-trailer side-dump haulers and 22% of its 32 rear-dump trucks. In comparison, engine overhauls account for only 6% of the maintenance dollar. Doubling the present engine life would save only 3%. The open-pit mine, located near Babbitt, Minn., moves about 46 million t/y with its off highway fleet. Mine roadways total in excess of 160 km (100 miles) and about 1200 tires are in active use at any given time.

Jan 3, 1978

By G. J. Ballmer

Drilling and blasting 12-in. blastholes started about the middle of 1946 and has worked out so well that about one half of the blasting, formerly done with 9-in. holes, is now done with 12-in. holes. In most of this work the harder benches were chosen for the 12-in. size because these were the areas where the greatest difficulty was encountered in thorough fragmentation. At the start of this experimental work a 42-T Bucyrus- Erie churn drill was available whereas all other blasthole drilling was being done with 29-T rigs. The large drill was first equipped with a standard 9-in. string of tools but it could not drill quite as fast as the 29-T drills. How- ever, when the weight of the string was increased about 700 lb, or to a total weight of about 3500 lb, it was found that the 42-T exceeded the drilling speed of the 29-T by about 25 per cent. When a 12-in. bit was substituted for the 9-in. bit the 42-T rig again dropped behind the drill- ing rate of the 29-T rigs. At this stage of the experiment the 42-T was using a 12-in. bit with detachable points and the total weight of the string of tools was about 3800 lb. It took longer to change the drill points than it did the regulation bit and this accounted for some of the slower drilling rate. When a heavier stem and standard construction 12-in. bits were used it was found that the 42-T could drill a 12-in. hole slightly faster than a 29-T could drill a 9-in. hole even in the hardest rock in the pit.

Jan 1, 1949

By Victor A. Phillips

A series of strips of a Ni-12.7 at. pct A1 alloy were Prepared containing cubical y'(NisAl) precipitates with edge lengths from 60 to 500A. A particle-free solution-tveated strip was included for cornparison. They weve cold-rolled 95 pct and the effects of particle size on the isochronal (1/2 hr) annealing behavior between 300° and 950°C studied (by hardness and light and electron microscopy). It ulas inferred that the particles deformed with the lnatvix becoming lamellae which remained coherent. Comparison with published data fov pure nickel showed that aluminum greatly re-tavded softening and recrystallization, but it made little difference whether or not particles were present. The presence of pakticles led to a heterogeneous distribution of precipitates after annealing at 700" to 750°C. Recovery was not detected. Recrystallization occurred by the growth of new grains into unrecrys-tallized material. In a previous study by the author,' the growth of Ll2-type ordered yl(Ni3Al) precipitates was followed in Ni-12.7 at. pct A1 alloy as a function of aging at 600" and 700°C. The particles were showo to be cubical in shape in all sizes from 50 to 3000A and remained coherent. This work was used as a guide in preparing the starting structures for the present study of the effect of these particles on the annealing behavior of heavily cold-rolled strip. Another question of present interest was whether dislocation and particle hardening were additive, since the structures before rolling ranged from solution-treated to peak-aged to overaged. Also, precipitation might occur on annealing after cold-rolling. Reference may be made to other papers2"5 for previous work in this relatively unexplored field and only some recent work will be mentioned her:. phillips2 studied the effect of deformable 0 to 590A-diam cobalt particles on a Cu-3.23 pct Co alloy rolled 95 pct and found that the particles, which rolled out into thin lamellae, impeded softening and recrystallization. Tanner and servi3 likewise studied the annealing of cold-swaged Cu-2 pct Co alloy containing 150A-diam particles and found impeding effects. Haessner et a1.,4 on the other hand, found that incoherent 2-p-diam non-deformable particles of B4C (0.04 vol pct) tended to increase the rate of recrystallization of copper rolled up to 95 pct reduction. They attributed this to the formation of new grains at the particle interfaces. Humphreys and artin' found that nondeformable silica particles in copper rolled to 30 pct reduction accelerated recrystallization if the particle spacing was large and retarded it if the spacing was smaller. Haessner et a1 4 also studied a rolled Ni-Cr-A1 alloy; however, the particles of y'(Ni3Al)-type precipitate were not put in before rolling, but separated during the isothermal annealing at 750°C. No previous work appears to have been carried out on the effect of y' (Ni3A1) particles on the annealing of Ni-A1 alloy. Hornbogen and ICreye7 redetermined the solubility c of aluminum in nickel as a function of temperature T and showed that it was given by c = 32.6 exp(-1940/RT). This relation gives aluminum solubilities of 15.1, 14.2, 12.0, and 10.7 at. pct at 1000°, 900°, 700°, and 600°C, respectively. The phase precipitated from the nickel-rich solid solution is fcc y1 (Ni3A1) which has a Cu3Au -type ordered structure8 and remains ordered up to 1000°C.B EXPERIMENTAL PROCEDURE The alloy used was identical with that used before. Chemical analysis showed 6.27 wt pct (12.71 at. pct) Al, the principle impurities being 0.065 pct Fe, 0.022 pct Co, 0.020 pct Cu, and 0.004 pct C. Bar stock of 1 in. diam was cold-swaged to % in. diam, cold-rolled to 0.300-in.-thick strip, and annealed at 900°C in dry hydrogen. It was cold-rolled to 0.100-in. thickness and solution-treated for 1 hr at 1000°C while sealed in a quartz tube in argon, quenching in iced brine with the aid of a device to snap off the nose of the tube. Lineal analysis gave an average grain size of 0.055 mm. Pieces of strip were aged at 700°C in vacuo for 30 min, 51/4 hr, and 1 week to produce nominal average particle widths of 60, 150, and 500A, respectively, as known from the previous work.' The average diamond pyramid hardness was determined. The heat-treated strips were rolled from 0.100 to 0.005 in., a reduction of 95 pct, and the rolled strips stored at about -5°C. Small pieces were annealed within 1 week for 30 min at temperatures from 300° to 950° ±2°C in a horizontal vacuum furnace. Strips were withdrawn into a cooling zone, giving an estimated initial cooling rate from 950°C of about 50°C per sec. Average diamond pyramid hardnesses were determined on a lightly electropolished spot on the surface of each strip using 300-g load. Each point on the softening curves represents a separate annealed specimen. Sections containing the rolling direction were examined by optical metallography. Selected specimens were electrothinned to the center plane' and examined by transmission at 100 kv in a Siemens Elmiskop I electron microscope. It is well-known that changes in the structure tend to occur when a deformed strip is electrothinned below a thickness of a few hundred angstroms, although this is less serious with a material such as nickel which has a high melting point, and also is apt to be less serious when particles are present. Observations were nevertheless confined to thicker regions of the foils with estimated thicknesses over 1000A. No changes were observed due to beam exposure.

Jan 1, 1968

By Walter R. Hibbard

THE term lineage was first introduced by Buerger1 to denote dendritic branches, grown from a crystal nucleus during solidification from the liquid, with imperfections in alignment of the order of 10-1 [ ] to 10-4 cm. These imperfections are associated with distortions of the dendrites caused by the subsequent solidification of the inter-dendritic filling and are illustrated in Fig 11. Buerger etched zinc single crystals made by the Bridgman2 method to develop this dendritic pattern and show lineage microscopically. Since maximum crystal growth in face-centered cubic metals occurs along the [100] directions,2 lineage would appear in copper as small deviations of dendritic branches from these directions. Elam4 and others5-8 reported etching effects resulting from coring along the cube face traces of various copper alloy crystals. These traces were used by Samans8 to orient single crystals. Williamson9 noted a "lined structure (in alpha brass single crystals) consisting of an ordered arrangement of etch pits" which were probably traces of {100} planes but somewhat uncertain because they were never straight (i.e., apparently lineage). Greninger10 described the distortion and multiplicity of Laue spots in back reflection X ray photograms of copper single crystals showing lineage. The present investigation includes metallographic, X ray and property studies of lineage in large grain and single crystal specimens of copper. PREPARATION OF SPECIMENS Specimens 10 in. long and ½ in. diam of oxygen-free copper (O.F.H.C.) (99.985 pct) were melted vertically in graphite crucibles under an atmosphere of commercial nitrogen purified through a gas train including sulfuric acid, potassium chloride, magnesium chlorate, hot copper chips and phosphorus pentoxide. After a temperature of 1200°C had been maintained for ½ hr, the furnace was turned off and the specimens cooled at a rate of about 150°C an hour. This method of direct solidification was used by Greninger10 to produce single crystals with marked lineage and in this investigation produced a fair yield of single crystal specimens in

Jan 1, 1947

By John Wulff, J. H. Hollomon

SERVICE failures in brass condenser tubes are often due to corrosion. One of the commonest types of corrosion reveals a surface structure of redeposited copper.1 The study of the effect of alloy addition agents in preventing this kind of corrosion has received impetus from the extensive publication of Bengough and May.2 The mechanism of such inhibition gauged from immersion corrosion,' cell corrosion,' and electrolytic potential' measurements is controversial. This controversy may be attributed in part to a lack of definite knowledge5 of the actual nature of the initial films formed in corrosion experiments. In our own corrosion work on copper and 70-30 brass this lack became apparent and necessitated an examination of surface films by X-ray and electron diffraction methods. The present paper is but an introduction to the subject of inhibition and reports the structure of films formed in active corrodents. EXPERIMENTAL PROCEDURE The arsenical coppers and brasses used in this investigation were made by one of the writers* in the plant of the Revere Copper and Brass Co. at Rome, N. Y. Standard commercial melting practice was followed. O.F.H.C. copper and electrolytic zinc were used and all arsenic additions were made by additions of a master copper alloy. The final analyses are given in Table I. Likewise, the extrusion, cold-rolling, and intermediate anneals employed followed standard usage. Final heat-treatments were given to all materials to produce a similar grain size (0.035 to 0.045 mm. for brass and 0.015 to 0.025 for [ ] copper) for the alloys containing various percentages of arsenic. Samples ¼ by ½ by ¼ in. were cut from sheet material resurfaced and finished with 0000 metallographic papers. The surfaces were all degreased in alcohol and benzine before immersion. After immersion in the corrodent, they were washed gently in tap water, dipped first in alcohol and then in pure benzine and allowed to dry in the diffraction apparatus. The reflection electron diffraction apparatus used has been described by Burwell

Jan 1, 1941

By M. V. Nevitt

THE Cr,O-type, or P-tungsten, structure having the space group (Oh2— Pm,n) is one of the most widely occurring structures found among the intermediate phases involving transition metals. Including the phases reported here for the first time, the total number of these A,B phases now known is 39. Greenfield and Beck' have correlated the lattice parameters of these phases with the Goldschmidt radius of the close-packed chains of A atoms. Laves' discussed the apparent size of the A and B atoms in this structure. Gel1er" proposed a scheme for reproducing the lattice constants of the phases by the use of a list of effective C.N. 12 radii for the component elements. Reported here is a survey of the A,B combinations which appeared favorable for the stability of the Cr,O-type phase but which, at the time the investigation was begun, either had not been reported upon or had conflicting reports as to the existence of the structure. Seventy systems were investigated, and 8 Cr,,O-type structures were found. Six of these also were reported by other investigators in the interval between the start of this investigation and its completion. This survey yielded information as to the influence of the relative sizes of the A and B atoms on the stability of the phase and, for the various families of Cr,O-type phases, the effects of the sizes of the A and B atoms on the lattice constant. Likewise, a somewhat clearer picture of the connection between the position of the A and B elements in the Periodic Table and their Cr,O-type phase-forming tendencies has become apparent. Experimental Procedure Alloys were prepared in the form of arc-melted 3-gram buttons in all cases where the vapor pressure of neither component was high enough to cause

Jan 1, 1959