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Metallography of wrought vacuum-cast beryllium at elevated temperatures
Classified
abstracts
445-459
31 445. Kinetics of degasification of liquid steel in vacuum. (USSR) The degasification rate of nonreduced ball-bearing steel in foils of different thickness can be described by an experimental diagram. The maximum characterises the effect of two contrasting factors, the decrease of bubbles during floating and the decrease of the interphase surface of the bubble origin. The degasification rate during boiling is higher than that taking place in the diffusion process with subsequent desorption at an uncovered metal surface. During evacuation of reduced steel by the decanting method a greater part of the gases separate from the boiling surface. 0 Kh Fatkullin et al, Sb Mosk Inst Stali i Splavov, No 41, 1966, 151-160
(in Russian). 37 : 41 of niobium in
446. Vacuum thermal expansion tester for investigations the 20 to 1,600”C temperature range. (USSR)
The device for measuring the elongation of Nb samples with dimensions diameter 6 mm x 150 mm at 1O-6 torr is described. The expansivity of Nb at the temperature range 20-1,600”C is Al&= -13.7 x 1O-5+68.5x lO~‘t+1.26x 10m9t3. B E Neymark and B R Brodskiy, %avodsk Lab, 32 (9)) 1966,1154-l 155 (in Russian) 447. Metallography of wrought temperatures. (USA)
vacuum-cast
beryllium
37 at elevated
Microstructural changes in wrought vacuum-cast beryllium at elevated temperatures were studied with a vacuum hot-stage metallograph. The phenomena of grain growth and the removal of mechanical twins from the microstructure were recorded with a 16 mm tine camera. V R Friehel, Rep RFP-544, Co Golden, Colorado).
Nov 1965 (Rocky
Flats Div Dow Chemical
448. Vacuum metallurgical
equipment and processes.
(Great
37 Britain)
A review is given of the characteristics of vacuum pumps available for processing work. T Thorley, Metal Treatment Drop Forging, 33, 1966, 123-141. 37 449. Variables affecting nitrogen removal in the vacuum-induction heating of iron- and Ni-base alloys. (Great Britain)
The basic thermodynamic considerations of the nitrogen reaction in Fe- and Ni-base alloys are discussed, and the literature is reviewed. The present investigation studies the nitrogen removal from alloys produced in a laboratory vacuum-induction furnace. A Simkovich,
J Metals,
18, 1966, 504-512. 37
450. Degassing metallic melts in ladle by vacuum treatment. (Great Britain)
After applying vacuum to a filled ladle until gas evolution seems to have stopped, the bubbling can be reactivated near the top of the ladle by dropping in a small amount of fine solid granules, of the same composition as the melt, for nucleation. Dortmund-Hoerder Huettenunion, British Patent 1,037,369 27th July 1966, 2 pages. 37 451. Clinkering of gas coal in a vacuum. (USSR) L P Bezuglyi and G G Rabukhina, Met i Koksokhim, (in Russian).
5, 1966, 3-11 37
452. Melting of iron, nickel and cobalt alloys in vacua. A review article. F Spemer, Tech Mitt, 59, 1966, 110-116 (in German).
(Germany)
37 453. Sublimation rates in vacua of PbTe and PbSnTe thermoelements. (USA) H E Bates and M Weinstein, Advanced Energy Conversion, 6, 1966, 177-180. isotopic gas analysis 38 454. Semicontinuous vacuum distillation and its application in the fabrication of very pure bismuth and selenium of rectifier quality. (Germany)
38.
Distillation,
organic
chemistry,
Semicontinuous vacuum distillation for refining of Bi and Se was investigated using a quartz apparatus. For distillation of Bi, temperatures from 950-1000°C were employed at a residual gas pressure of 122
10-a torr. The distillation of Se was carried out at temperatures below 350°C. S Richter and L Muller, Freiberger Forschungsh, 112b, 1966, 127-158 (in German).
39. Miscellaneous 455. Cold molecular
applications
39
welding study in ultrahigh vacuum.
(USA)
Cold molecular welding of typical metals which are being used or considered for the Apollo mission was studied. The coefficients of friction were determined for various metal combinations under specified conditions. The rating of the 45 metal combinations is based on static breakaway friction after 300 hr of contact and short time dynamic conditions. In addition to the ultrahigh vacuum tests for 45 metal combinations, the comparative effects of operation in air versus ultrahigh vacuum were determined for four metal combinations. The test apparatus used three pellets resting or being rotated on an annular wear track, with a 1000 psi contact pressure between the pellets and the wear surface. The design incorporated heaters for maintaining the wear surfaces at approximately 200°C. The coefficient of friction was determined by measuring the torque necessary to rotate the pellets. The mechanism was enclosed in a stainless steel chamber and evacuated with an oil-free vacuum pumping system capable of maintaining pressures in the 10e9 and lo-l0 torr range. C E Moeller et al, Rep NASA-CR-65390, Nov 1965 (Midwest Research Inst, Kansa City, MO). 39 456. Creep at elevated temperatures
and high vacuum.
(USA)
A series of high purity copper wires were creep tested in high vacuum at temperatures between 785” and 855”C, both in the argon bombarded clean state and after oxidizing in air at these elevated temperatures. It was found that the creep rate of the sample decreased noticeably after oxidation for about one hour between 400” and 500°C. The sample fractures in the oxidized state in test above 835°C. The largest minimum creep rate of the argon bombarded clean sample was about 0.1 per cent per minute, whereas that for the oxidized sample under the same stress of about 850 g/cm” was less than 0.2 per cent per minute. It is proposed that the creep phenomena can be explained with a model, in which oxide films act as dislocation barriers for dislocation. K Schroder et al, Rep NASA-CR-76088; SURI-MET-E-1189-566SA, May 1966 (Syracuse Univ Res lnst New York, Dept of Chemical Engineering and Metallurgy). 39 457. Determination of elevated-temperature fatigue data on refractory alloys in ultrahigh vacuum. (USA)
The results of fatigue tests conducted on molybdenum-base alloys at elevated temperatures in ultrahigh vacuum environments are reported. The specific material form of the TZM and TZC alloys (bar or plate), their heat numbers, and their chemical composition are given in a table. Typical microstructures of the TZC after annealing are shown, and fatigue curves are plotted as function of stress values. C R Honeycutt and J C Sawyer, Rep NASA-CR-54916, Jan 1966 (TRW
Equipment
Labs, Cleveland,
Ohio).
458. Automatic vacuum weighing apparatus decomposition kinetics of solids. (USSR)
for
investigating
39 the
The construction of an apparatus with automatic recording of the variation in weight of a substance is described. It consists of a quartz spring balance, a projecting device to present a magnified image of the lower end of the balance coil, and a photoelectric device to record the displacement of the lower end of the coil. A photosensor is connected in one arm of an electronic amplifier bridge. When the intensity falling on the photosensor is dismissed due to unbalance of the bridge, a reversing servomotor moves the photosensor out of the shadow zone. The stylus of the automatic recording device traces out the motion of the photosensor. The weight range is from 1 to 20 mg with an error of 1 x 1OMB g in recording a 30 per cent weight loss. V I Versohkm and V T Dis’menko, English Transl from Kinetika i Kataliz (USSR), 6 (61, 1965, 1121-1212, Rep NASA-TT-F-100 96, April 1966. 39 459. Lubricant study in ultrahigh vacuum and in various gas environments.
Wear and friction
characteristics
of lubricated
and unlubricated
abstracts
445-459
31 445. Kinetics of degasification of liquid steel in vacuum. (USSR) The degasification rate of nonreduced ball-bearing steel in foils of different thickness can be described by an experimental diagram. The maximum characterises the effect of two contrasting factors, the decrease of bubbles during floating and the decrease of the interphase surface of the bubble origin. The degasification rate during boiling is higher than that taking place in the diffusion process with subsequent desorption at an uncovered metal surface. During evacuation of reduced steel by the decanting method a greater part of the gases separate from the boiling surface. 0 Kh Fatkullin et al, Sb Mosk Inst Stali i Splavov, No 41, 1966, 151-160
(in Russian). 37 : 41 of niobium in
446. Vacuum thermal expansion tester for investigations the 20 to 1,600”C temperature range. (USSR)
The device for measuring the elongation of Nb samples with dimensions diameter 6 mm x 150 mm at 1O-6 torr is described. The expansivity of Nb at the temperature range 20-1,600”C is Al&= -13.7 x 1O-5+68.5x lO~‘t+1.26x 10m9t3. B E Neymark and B R Brodskiy, %avodsk Lab, 32 (9)) 1966,1154-l 155 (in Russian) 447. Metallography of wrought temperatures. (USA)
vacuum-cast
beryllium
37 at elevated
Microstructural changes in wrought vacuum-cast beryllium at elevated temperatures were studied with a vacuum hot-stage metallograph. The phenomena of grain growth and the removal of mechanical twins from the microstructure were recorded with a 16 mm tine camera. V R Friehel, Rep RFP-544, Co Golden, Colorado).
Nov 1965 (Rocky
Flats Div Dow Chemical
448. Vacuum metallurgical
equipment and processes.
(Great
37 Britain)
A review is given of the characteristics of vacuum pumps available for processing work. T Thorley, Metal Treatment Drop Forging, 33, 1966, 123-141. 37 449. Variables affecting nitrogen removal in the vacuum-induction heating of iron- and Ni-base alloys. (Great Britain)
The basic thermodynamic considerations of the nitrogen reaction in Fe- and Ni-base alloys are discussed, and the literature is reviewed. The present investigation studies the nitrogen removal from alloys produced in a laboratory vacuum-induction furnace. A Simkovich,
J Metals,
18, 1966, 504-512. 37
450. Degassing metallic melts in ladle by vacuum treatment. (Great Britain)
After applying vacuum to a filled ladle until gas evolution seems to have stopped, the bubbling can be reactivated near the top of the ladle by dropping in a small amount of fine solid granules, of the same composition as the melt, for nucleation. Dortmund-Hoerder Huettenunion, British Patent 1,037,369 27th July 1966, 2 pages. 37 451. Clinkering of gas coal in a vacuum. (USSR) L P Bezuglyi and G G Rabukhina, Met i Koksokhim, (in Russian).
5, 1966, 3-11 37
452. Melting of iron, nickel and cobalt alloys in vacua. A review article. F Spemer, Tech Mitt, 59, 1966, 110-116 (in German).
(Germany)
37 453. Sublimation rates in vacua of PbTe and PbSnTe thermoelements. (USA) H E Bates and M Weinstein, Advanced Energy Conversion, 6, 1966, 177-180. isotopic gas analysis 38 454. Semicontinuous vacuum distillation and its application in the fabrication of very pure bismuth and selenium of rectifier quality. (Germany)
38.
Distillation,
organic
chemistry,
Semicontinuous vacuum distillation for refining of Bi and Se was investigated using a quartz apparatus. For distillation of Bi, temperatures from 950-1000°C were employed at a residual gas pressure of 122
10-a torr. The distillation of Se was carried out at temperatures below 350°C. S Richter and L Muller, Freiberger Forschungsh, 112b, 1966, 127-158 (in German).
39. Miscellaneous 455. Cold molecular
applications
39
welding study in ultrahigh vacuum.
(USA)
Cold molecular welding of typical metals which are being used or considered for the Apollo mission was studied. The coefficients of friction were determined for various metal combinations under specified conditions. The rating of the 45 metal combinations is based on static breakaway friction after 300 hr of contact and short time dynamic conditions. In addition to the ultrahigh vacuum tests for 45 metal combinations, the comparative effects of operation in air versus ultrahigh vacuum were determined for four metal combinations. The test apparatus used three pellets resting or being rotated on an annular wear track, with a 1000 psi contact pressure between the pellets and the wear surface. The design incorporated heaters for maintaining the wear surfaces at approximately 200°C. The coefficient of friction was determined by measuring the torque necessary to rotate the pellets. The mechanism was enclosed in a stainless steel chamber and evacuated with an oil-free vacuum pumping system capable of maintaining pressures in the 10e9 and lo-l0 torr range. C E Moeller et al, Rep NASA-CR-65390, Nov 1965 (Midwest Research Inst, Kansa City, MO). 39 456. Creep at elevated temperatures
and high vacuum.
(USA)
A series of high purity copper wires were creep tested in high vacuum at temperatures between 785” and 855”C, both in the argon bombarded clean state and after oxidizing in air at these elevated temperatures. It was found that the creep rate of the sample decreased noticeably after oxidation for about one hour between 400” and 500°C. The sample fractures in the oxidized state in test above 835°C. The largest minimum creep rate of the argon bombarded clean sample was about 0.1 per cent per minute, whereas that for the oxidized sample under the same stress of about 850 g/cm” was less than 0.2 per cent per minute. It is proposed that the creep phenomena can be explained with a model, in which oxide films act as dislocation barriers for dislocation. K Schroder et al, Rep NASA-CR-76088; SURI-MET-E-1189-566SA, May 1966 (Syracuse Univ Res lnst New York, Dept of Chemical Engineering and Metallurgy). 39 457. Determination of elevated-temperature fatigue data on refractory alloys in ultrahigh vacuum. (USA)
The results of fatigue tests conducted on molybdenum-base alloys at elevated temperatures in ultrahigh vacuum environments are reported. The specific material form of the TZM and TZC alloys (bar or plate), their heat numbers, and their chemical composition are given in a table. Typical microstructures of the TZC after annealing are shown, and fatigue curves are plotted as function of stress values. C R Honeycutt and J C Sawyer, Rep NASA-CR-54916, Jan 1966 (TRW
Equipment
Labs, Cleveland,
Ohio).
458. Automatic vacuum weighing apparatus decomposition kinetics of solids. (USSR)
for
investigating
39 the
The construction of an apparatus with automatic recording of the variation in weight of a substance is described. It consists of a quartz spring balance, a projecting device to present a magnified image of the lower end of the balance coil, and a photoelectric device to record the displacement of the lower end of the coil. A photosensor is connected in one arm of an electronic amplifier bridge. When the intensity falling on the photosensor is dismissed due to unbalance of the bridge, a reversing servomotor moves the photosensor out of the shadow zone. The stylus of the automatic recording device traces out the motion of the photosensor. The weight range is from 1 to 20 mg with an error of 1 x 1OMB g in recording a 30 per cent weight loss. V I Versohkm and V T Dis’menko, English Transl from Kinetika i Kataliz (USSR), 6 (61, 1965, 1121-1212, Rep NASA-TT-F-100 96, April 1966. 39 459. Lubricant study in ultrahigh vacuum and in various gas environments.
Wear and friction
characteristics
of lubricated
and unlubricated