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427a. Welding and brazing two columbium alloys
400
Abstracts 419--427a
Vacuum Applications 30.
Evaporation and Sputtering 30
419. Evaporation from Liquid Surface under a High and a Medium
Vacuum. Japan. Evaporation of di-2-ethylphthalate under a high and a medium vacuum was investigated. Changing the pressure, the author found that the evaporation mechanism could be thought as it is considered by two different ways. The author proposes these should be called as a " molecular-projective-evaporation" and a " molecular-burst-evaporation ". The former is observed under a high vacuum and follows Knudsen's high vacuum evaporation rate, but the latter is observed under a medium vacuum and its rate is strongly influenced by the vapor pressure of liquid and pressure of inert gas. Under a medium vacuum the evaporation rate is always less than Knudsen rate, and the author proposes the fundamental relation between rate and pressure considering the evaporating molecules slip diffuse through its vapor and inert gas, and presents the following equation : D = {MD/~rp/RoT(x-x')} ln(PrJPrv) where D : evaporation rate per unit area, D / : diffusion constant, M : Molecular weight, ~rp : total pressure, Ro : ideal gas constant, T : absolute temperature, x : distance from evaporating surface to condensing surface, x ' : thickness of molecular-exchange zone, Pro: inert gas pressure at nearer condensing surface, Pry: inert gas pressure at nearer evaporating surface, ft. N. H. Uyeha, T. Kajiura and O. Yoshikawa, Chem. Eng., Japan, 24, 274-280, 1960. 30
420. Thick Vacuum Metallized Coatings are Durable, Corrosion Resistant. This article describes a new method of vacuum-depositing metal coatings up to thicknesses of a few mils. Various types of coating materials are described together with applications of these materials. A.G. Philip J. Clough and Howard M. Farrow, Metal Prog., 52, 12-15, Sept. 1960.
31.
Evacuation and Sealing 31
421. The Radiolysis of Deuterated Biphenyis : Mechanism of Hydrogen Formation. J. G. Burr and J. M. Scarborough, J. Phys. Chem., 64, 1367-1374, Oct. 1960.
condenser lens, hole, project lens, and sector. The light modulated by sector which has frequency of 1000 c.p.s., passes through vacuum deposited thin film, and converted to signed photocell and amplified. Monitoring this signal, the authors say that it is easily possible to measure and control the thickness of the film. H.N. T. Sawaki, M. Iwata and S. Katsube, J. Vac. Soc., Japan, 3, 304-308, 1960.
36.
Drying, Degassing and Concentration 36
424. Fundamental Study of Vacuum Drying. Japan. Using Shigaraki clay as a testing material, the authors investigated the mechanism of vacuum drying. The pressure was between 4-300 mmHg, and heating device was in two cases : by radiation and conduction. Thickness of the testing material had no influence on the rate. Surface evaporation coefficient Kg is defined as R = Kg(pm-p) = Kg(Ap), where R is constant drying rate, Pm i~ water vapor pressure on the surface of material, P is water vapor pressure in the vessel, and Ap is the difference. Using this Kg, the experimental results were tabulated, the authors concluded as all mechanism was considered as a typical case of drying of the porous material. The influence of air leak varies the rate, and also in this case the equation Kg = 4.4 × 10-8 7r-2/3 was fully adoptable, where Kg is surface evaporation coefficient and K is pressure in mmHg. ft. N. R. Toei, K. Maeda, T. Yamauchi, T. Fuha, K. Wada and H. Yamamoto, Chem. Eng., Japan, 24, 289-297, 1960.
37.
Metallurgy, Inorganic C h e m i s t r y , A n a l y t i c a l Chemistry
37 425. Which Brazing Alloys for Vacuum Systems ? The properties of brazing alloys required to produce vacuumtight joints are discussed with particular emphasis on avoiding high vapor pressure constituents and impurities and the ability to wet and flow. An equilibrium diagram is included to explain brazing problems. A.G. Walter Hack, Materials in Design Engineering, 52, 116-117, July 1960. 37 426. Electron Beam Welding : Emphasis on Precision and Free-
33.
General Physics and Electronics 33
dom From Contamination. Marsbed Hablanian, Metal Prog., 78, 127-129, July 1960.
422. On the Characteristics of Steam Ejectors and a Method of
Calculating Their Performances. Japan. It is rather difficult to predict the performance of steam ejector, because it is influenced by many factors which cannot be predicated by design, and usually we decide the detailed constructions by our experiences. The author presents the practical method of calculating the performance. H.N. T. Ueda, Chem. Eng., Japan, 24, 264-273, 1960. 33
423. Photoelectric Devices for Monitoring Thickness of Vacuum Deposition of Multilayer Film. Japan. A practical and reliable device to measure and control the thickness of multilayer films deposited in vacuum was described. Light source was constructed by 12 V 20 W lamp,
37
427. Vacuum Markets.
Melters Push
Expansion--Bank on
Growing
The growth of vacuum melting capacity in the U.S.A., both consumable electrode and induction, is represented in graphical form. The locations of present and planned facilities for vacuum melted metals are listed. The dependence on the defense industry is discussed. A. ~. G. J. McManus, Iron Age, 186, 113-116, Oct. 1960. 37 427a. Welding and Brazing Two Columbium Alloys. C. F. Burrows, M. M. Schwartz and L. J. Gagola, Materials in Design Engineering, 52, 13-15, Oct. 1960.
Abstracts 419--427a
Vacuum Applications 30.
Evaporation and Sputtering 30
419. Evaporation from Liquid Surface under a High and a Medium
Vacuum. Japan. Evaporation of di-2-ethylphthalate under a high and a medium vacuum was investigated. Changing the pressure, the author found that the evaporation mechanism could be thought as it is considered by two different ways. The author proposes these should be called as a " molecular-projective-evaporation" and a " molecular-burst-evaporation ". The former is observed under a high vacuum and follows Knudsen's high vacuum evaporation rate, but the latter is observed under a medium vacuum and its rate is strongly influenced by the vapor pressure of liquid and pressure of inert gas. Under a medium vacuum the evaporation rate is always less than Knudsen rate, and the author proposes the fundamental relation between rate and pressure considering the evaporating molecules slip diffuse through its vapor and inert gas, and presents the following equation : D = {MD/~rp/RoT(x-x')} ln(PrJPrv) where D : evaporation rate per unit area, D / : diffusion constant, M : Molecular weight, ~rp : total pressure, Ro : ideal gas constant, T : absolute temperature, x : distance from evaporating surface to condensing surface, x ' : thickness of molecular-exchange zone, Pro: inert gas pressure at nearer condensing surface, Pry: inert gas pressure at nearer evaporating surface, ft. N. H. Uyeha, T. Kajiura and O. Yoshikawa, Chem. Eng., Japan, 24, 274-280, 1960. 30
420. Thick Vacuum Metallized Coatings are Durable, Corrosion Resistant. This article describes a new method of vacuum-depositing metal coatings up to thicknesses of a few mils. Various types of coating materials are described together with applications of these materials. A.G. Philip J. Clough and Howard M. Farrow, Metal Prog., 52, 12-15, Sept. 1960.
31.
Evacuation and Sealing 31
421. The Radiolysis of Deuterated Biphenyis : Mechanism of Hydrogen Formation. J. G. Burr and J. M. Scarborough, J. Phys. Chem., 64, 1367-1374, Oct. 1960.
condenser lens, hole, project lens, and sector. The light modulated by sector which has frequency of 1000 c.p.s., passes through vacuum deposited thin film, and converted to signed photocell and amplified. Monitoring this signal, the authors say that it is easily possible to measure and control the thickness of the film. H.N. T. Sawaki, M. Iwata and S. Katsube, J. Vac. Soc., Japan, 3, 304-308, 1960.
36.
Drying, Degassing and Concentration 36
424. Fundamental Study of Vacuum Drying. Japan. Using Shigaraki clay as a testing material, the authors investigated the mechanism of vacuum drying. The pressure was between 4-300 mmHg, and heating device was in two cases : by radiation and conduction. Thickness of the testing material had no influence on the rate. Surface evaporation coefficient Kg is defined as R = Kg(pm-p) = Kg(Ap), where R is constant drying rate, Pm i~ water vapor pressure on the surface of material, P is water vapor pressure in the vessel, and Ap is the difference. Using this Kg, the experimental results were tabulated, the authors concluded as all mechanism was considered as a typical case of drying of the porous material. The influence of air leak varies the rate, and also in this case the equation Kg = 4.4 × 10-8 7r-2/3 was fully adoptable, where Kg is surface evaporation coefficient and K is pressure in mmHg. ft. N. R. Toei, K. Maeda, T. Yamauchi, T. Fuha, K. Wada and H. Yamamoto, Chem. Eng., Japan, 24, 289-297, 1960.
37.
Metallurgy, Inorganic C h e m i s t r y , A n a l y t i c a l Chemistry
37 425. Which Brazing Alloys for Vacuum Systems ? The properties of brazing alloys required to produce vacuumtight joints are discussed with particular emphasis on avoiding high vapor pressure constituents and impurities and the ability to wet and flow. An equilibrium diagram is included to explain brazing problems. A.G. Walter Hack, Materials in Design Engineering, 52, 116-117, July 1960. 37 426. Electron Beam Welding : Emphasis on Precision and Free-
33.
General Physics and Electronics 33
dom From Contamination. Marsbed Hablanian, Metal Prog., 78, 127-129, July 1960.
422. On the Characteristics of Steam Ejectors and a Method of
Calculating Their Performances. Japan. It is rather difficult to predict the performance of steam ejector, because it is influenced by many factors which cannot be predicated by design, and usually we decide the detailed constructions by our experiences. The author presents the practical method of calculating the performance. H.N. T. Ueda, Chem. Eng., Japan, 24, 264-273, 1960. 33
423. Photoelectric Devices for Monitoring Thickness of Vacuum Deposition of Multilayer Film. Japan. A practical and reliable device to measure and control the thickness of multilayer films deposited in vacuum was described. Light source was constructed by 12 V 20 W lamp,
37
427. Vacuum Markets.
Melters Push
Expansion--Bank on
Growing
The growth of vacuum melting capacity in the U.S.A., both consumable electrode and induction, is represented in graphical form. The locations of present and planned facilities for vacuum melted metals are listed. The dependence on the defense industry is discussed. A. ~. G. J. McManus, Iron Age, 186, 113-116, Oct. 1960. 37 427a. Welding and Brazing Two Columbium Alloys. C. F. Burrows, M. M. Schwartz and L. J. Gagola, Materials in Design Engineering, 52, 13-15, Oct. 1960.