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Study of the growth parameters involved in synthesizing boron carbide filaments
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
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