Design and operation of a vacuum cathodic etching unit

Classified

abstracts

416-428

The report describes the space simulation facilities presently available. The description includes temperature, pressure and irradiation capabilities, test instrumentation available and data handling capabilities. Anon, Jet Propulsion Lab Rep NASA-CR-74849; JPL-TM-33-197, Mar I965 (Calif Inst of Tech, Pasadena). 34 416. NASA/Langley 55 foot vacuum cylinder man rating. (USA) A 55 foot vacuum cylinder is described for use as a man rated chamber such that men equipped with pressurized suits can be assigned to perform tasks within the chamber representative of those required for servicing and repair of spacecraft in orbit and on extraterrestrial surfaces. The designs presented here have been performed in accordance with the requirements, and the design is grouped in seven systems. Anon, General Electric Co, Final Design Report NASA-CRd6076/ 1965 (General Electric Co, Philadelphia, Pa, Missile and Space Div). 34 : 39 417. Experimental investigation of ultrahigh vacuum adhesion as related to the lunar surface. (USA) In studying the ultra-high vacuum frictional-adhesional behavior of silicates it was found that general adhesion behavior was reproducible, although some differences in adhesion magnitude were recorded. This difference appears to be due to surface roughness effects. The vacuum system was modified to permit vacuum cleavage, and two runs involving vacuum cleavage were made. The adhesion forces were found to be large, and it was concluded that the adhesion was caused by normal silicate bonding forces and surface charges. J A Ryan, Rep NASA-CR-74625, March 1966 (Douglas Aircraft Co Santa Monica, Califl . 34 418. Space molecular sink simulator facility design. (USA) The report summarizes the results of research, design and development efforts for a space molecular sink simulation facility now under construction. The longitudinal-wedge-fin, 21°K hydrogen-refrigerated molecular-trap array has been shown to provide a capture improvement of an order of magnitude over that of smooth-walls, capturing 99.97 oer cent of the condensable molecules of 0,. N,. A. CO and CO, that ehanate from the test item before they can’ret;rn.’ An electron: beam titanium sublimator will be used to pump hydrogen and also to chemically permanently fixthecryodeposits. A 1300ft3/min mechanical pump (operated in the viscous-flow regime to eliminate backstreaming) and a 140 I/XC turbo-molecular impact pump will be used to rough the double-walled double-doored 10 ft-diam. vacuum chamber and to sustain the guard vacuum. The chamber is decontaminated by glass-bead blasting in conjunction with 250°C vacuum bake-out. J B Stephens, Rep NASA-CR-74654: JPL-TR-32-901 March 1966 (Jet Propulsion Lab, Calif Inst of Tech, Pasadena). 36. Drying,

degassing

and concentration

36 419. Processing of paper insulation. (Great Britain) In order to obtain good dielectric properties, the water content of the paper must be reduced to about 0.05 per cent and subsequent impregnation with oil or other dielectric must be carried out in such a way as to rigorously exclude the incorporation of gaseous species in the final product which might promote ionization phenomena under operational conditions. These conditions are fulfilled by drying under a vacuum of 10m2torr and impregnation at this pressure with an impregnant which has been degassed and stored under vacuum. A typical dehydration vacuum oven is illustrated which treats 9000 lb of paper involving the removal of 630 lb of water by 144 hours of heating and pumping. M J Dvornik, Component Tech&, 2 (3), Sept 1966, 26-28. 36 420. New type of vacuum crystallizer. (CzechosZovakia) A new type of a circulation vacuum crystallizer was constructed for obtaining coarse crystals by maintaining supersaturation at a required degree. L N Matusevich and V A Odintsev, Chem Prumysl, 16 (51, 1966, 262-267 (in Czech). 36 421. Vacuum-freeze conversion of salt water to drinking water. (Germany) Salt-free drinking water from brine solution is prepared by the continuous recycling from the ice-melt obtained after vacuum-freezing. 120

G M Ashley, German Patent 1,215,604, Appl 15th Nov 1958, 4 pages, 28th April 1966.

37. Metallurgy, 422. Development

inorganic

chemistry,

analytical

and evaluation of tungsten-base

37

: 41

alloys.

(USA) The investigation is concerned with the development of tungsten-base alloys having high strength at elevated temperatures. They contain carbon, Zr, Hf, Cb, or boron. All of the alloys were consolidated by vacuum arc melting. Primary working of the as-cast ingots was achieved by extrusion, the tungsten-base alloy blanks being encapsulated in molybdenum prior to extrusion. Additional working of the extruded materials was attempted by swaging. Even though the facilities utilized for swaging had temperatures available for heating of the work up to 3500°F the working temperatures were too low for successful swaging. Strength properties and recrystallization temperatures are reported for the alloys after extrusion and after swaging. These properties are dependent on the carbon and metallic alloy content. M Semchyshen et al, Rep AD-468299, Aug 1965 (Climax Molybdenum Co of Michigan, Ann Arbor Res Lab). 37 423. Study of the growth parameters involved in synthesizing boron carbide filaments. (USA) Boron carbide whiskers grown in a chimney-type resistance furnace were found to be of the curved instead of the more desirable straight variety. A radial-type furnace was developed which provided a more uniform thermal gradient in the growth region and produced straight short whiskers which were not long enough for reinforcement. Efforts to overcome this length deficiency have not been successful. Studies were, therefore, continued with the chimney-type whisker growth, and a new geometry has increased B,C whisker yield by a factor of ten. Annealing for five hours at 1900°C in vacuum has removed the curvature in these whiskers and the annealed whiskers appear to have smoother surface. The annealing, however, appears to have a weakening effect. A Gatti et al, Rep NASA-CR-75715, May 1966 (General Electric Co, Philadelphia, Pa, Missile and Space Div). 424. Unusually

extensive melting and heating facilities and Steel Corp. Part II. Melting. (USA)

37 at Erie For&?

Description o?facilities for the production of cast and forged steel parts, low, medium and high carbon and alloy castings and alloy steels. Equipment includes two acid open hearth furnaces of IOO-ton capacity, fired by steam atomized oil and a basic top-charge vacuum deoxidising electric furnace of 75 ton capacity, used for the production of Erie-V-Dok steel. Anon, Ind Heating, 32, 1966, 1063-1072, 1141. 37 425. Some aspects of liquid steel treatment under vacuum conditions. (Rumania) The thermodynamic and kinetic analyses of the processes occurring in the course of processing and casting of liquid steel in vacuum are reviewed. The processes considered were degassing, deoxidation, reduction of the nonmetallic inclusions and volatilization of some steel components. I Dragomir, Metalurgia, 18, 1966, 157-164. (in Rumanian). 37 426. Fatigue hehaviour of aluminium in vacuum. (USA) The fatigue properties of 1100 aluminium in reverse bending were studied at vacuum levels varying from lo-’ torr to atmospheric pressure. A substantial increase (up to ten-fold) in fatigue life was observed at pressures below 1O-2 torr which could be related to retardation of the crack propagation phase of the fatigue process. M J Hordon, Acta Metakrgica, 14, 1966, 1173. 427. Sliding behaviour vacuum. (USA)

of some layer-lattice

compounds

37 in ultrahigh

Friction measurements in ultrahigh vacuum were made on a series of layer-lattice compounds selected from a number of different crystal systems. Anon, Am Sot Lubrication Eng Trans, 9, 1966, 136-146. 37 428. Design and operation of a vacuum cathodic etching unit. (USA) The design, construction and operation of a vacuum cathodic etching instrument are discussed. A special feature of the design is a liquid

Classified

abstracts

42944

cooled Zr cathode with a horizontal surface for supporting the sample. W N Wise, National Lead Co, Cincinatti, Ohio, May 1966, 16 pages 37 429. Research on new methods for improving the ductility of molybdenum. (USA) Vacuum-arc-cast ingots are prepared using powder that has been treated in palladium-diffused hydrogen, then transferred to the melting furnace without exposure to air. Additions were made to the ingots so that various dwxidising agents could be. studied. M Semchyschen and R Q Rarr, J Less Common Metals, 11,1966, I-13. 31 430. Puri6cation of ahuninimn and its properties. (Italy) Details are presented on zone refining, double electrolysis and vacuum distillation methods which are currently used to obtain high purity Al. Activation analysis and resistivity measurement methods are used to determine the degree of purity. G Chaudron, Met Ital, 58, 1966, I-9 (in Italian). 37 431. LECO vacuum fusion analyzer. (Belgium) Oxygen in controlled amounts and nitrogen (not deliberately added) give Ti alloys strength and hardness; hydrogen causes brittleness. Samples are introduced through an evacuable chamber and dropped into a graphite crucible in the furnace without disturbing the vacuum. The liberated gases are rapidly transferred by a mercury vapour pump to a collection volume, where a portion is analyzed and the remainder of the apparatus outgassed. M J Miles and L C Covington, Metallurgic, 5,1965,367_575(in French). 37 432. Vacuum steelmaking. ( Yugoslavia) Technical procedures of vacuum steelmaking are described. Vacuum induction furnaces for 5-50 tons of steel and the degassing procedures with at least 20-30 tons of material are discussed. In distinction to the induction furnace (10-l to lo-‘ torr) the vacuum in the degassing procedure is between 0.1 and 10 torr. An outline of the more important vacuum degassing methods for molten steels is given and the original literature is cited. E Ploeckinger, Budarsko Met Zb, 1966,5-20 (in Slovene). 37 433. “ASEA-SKF” steal processing method. (Czechosfovakia) Molten steel is intensively mixed by electromagnetic forces during vacuum degassing and the steel is subsequently reheated by an arc in the same casting ladle. The apparatus used in SKF Works, Sweden, is described in detail. (Sweden) H Stickler, Proc First Nat Conf on Electra-Heat, Prague, Nov 1966 (in German). 37 434. Comparison of the influence of the electroslag method and vacua arc melting on steel properties. (Czechoslovakia) The advantage of the vacuum arc melting is the reliability of reduction in the gas content of the steel. However, mechanical properties of steel processed by vacuum are not better than those of the electroslag process. (Czechoslovakia) Z Buzek, Proc First Nat Conf on Electra-Heat, Prague, Nov 1966 (in Czech). 31 435. Characteristics of vacuum arc melting technology. (Czechoslovakia) The influence of electrode properties on vacuum arc melting of steel and the reduction of the contents of Mn and other components in steel during vacuum arc melting were investigated. Mechanical properties of vacuum melted steel and the basic vacuum metallurgy theory are briefly discussed. Z Eminger and Z Kletecka, Proc First Nat Conf on Electra-Heat, Prague, Nov 1966 (in Czech). 37 436. Multi-chamber furnaces heated by an electron beam. (Czechoslovakia) The design of type EM0 60 furnace manufactured by VEB H Beimler, Henningsdorf, East Germany, is described. This furnace is designed for melting rods by electron beams with energies up to 20 keV and currents up to 3 A. Simple focusing and deflection of the electron beam is possible. The electron source chamber is pumped by a separate pumping system so that processing chamber pressure rising up to 1 x 1O-2 torr does not atfect the electron source chamber pressure.

K Schmidt, Proc First Nat Conf Electra-Heat, Prague, Nov 1966, (in German). 37 437. Deoxidation during out-of-furnace vacuum treatment of steel. (Czechoslovakia) Vacuum treatment of the steel stream is employed both for the direct teeming of ingots into evacuated molds and for the pouring of steel from one ladle to another in a vacuum. For teeming ingots of under 40 tons, vacuum treatment of steel is used in the ladle. Steel subjected to vacuum treatment is manufactured with a content of about 0.15 per cent Si and without the addition of AI deoxidant. Vacuum treatment of steel modified by the addition of Al and Ti is described. J Skala, Hutnicke Listy, 21 (5), 1966 11-16 (in Czech). 37 438. The Finkf process of vacuum degassing. (Sweden) An outline.is given of the Fink1 nrocess. including the conditions for selecting this method, the steelmaking conditions, the importance of stirring, the plant required for the process, and the results of vacuum degassing. Future developments in steelmaking processes are discussed. A M Sagem, Tidskr Kjemi, Bergvesen, Met, 26, 1966, 85-89 (in English). 37 :42 439. New high-efficiency vacuum extrusion press. (Germany) A vacuum extrusion press for de-aerating and homogenizing plastic porcelain, whiteware and stoneware bodies is described. The principal improvements in the design are the incorporation of the vacuum pumping system within the extrusion press and a new feeding device which ensures a large adsorption capacity and removes the necessity for frequent stopping of the machine. The new press allows increases of 100 to 130 per cent in throughput rates compared with older models. B Reyer, Interceram, No 2, July 1966, 171-172 (in English). 37 448. Determination of hydrogen in carbon and alloy steels by vacuum anneal extraction. The variable conditions of hydrogen extraction for analysis and the reproducibility of the results were examined for nine types of steel, including carbon steels, hardenable and case hardening alloy steels, spring steels, and chromium steels with more than 7 per cent Cr. The results permit an exact description of the entire procedure of hydrogen determination for each type of steel from sampling to the laboratory. J Eisenkalb et al, Neue Hiitte, 10, 1966, 745-751 (in German). 37 441. Rapid determination of nitrogen in steels by vacuum melting extraction. (Germany) The commonly obtained low results for steels containing Al, Ti, and Zr can be avoided by premelting with Ta-Fe in ratios of 1.5:1 to 0X:1. H Severus-Laubenfrid et al, Z Anal Chem, 218, 1966, 241-249 (in German). 37 442. Container for the degasification of steel and other metals. (Germany) In a heated evacuable container for the degasification of molten steel or other metal, the heating means for the empty container are arranged in that zone of the container which after heating is covered by the liquid metal. The heating conductor for steel consists of Fe, steel or of metals which may be present in the steel. A Sickbert, (Bochumer C’erein fuer Luststahlfabrikation) German Patent 1,217,987 June 1966, Appl Nov 2 1961 3 pages. 37 443. Problems and experience in producing cast uranimn carbide rods. (Germany) Cast natural uranium monocarbide rods were produced by melting in an arc furnace and tilt pouring. The melting stock was produced in a semi-continuous vacuum induction furnace by the carbothermic reduction of UOa. L Schafer, Kerntechnik, 7, 1965, 359-361 (in German). 37 444. Vacuum degassing of metals. (Germany) The seals of vacuum degassing chambers are protected from spalling due to differential expansion if the jacket is anchored with a corrugated seal. J B Gero (Gero Metallurgical Corp) German Patent 1,219,634, June 23, 1966, Appl Nov 16, 1%1,6 pages. 121