639. Vacuum and non vacuum techniques for electron beam welding

639. Vacuum and non vacuum techniques for electron beam welding

Classified Abstracts cathode surface is necessary to account for the development of pyramidal structure. Such high mobility could be a consequence of ...

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Classified Abstracts cathode surface is necessary to account for the development of pyramidal structure. Such high mobility could be a consequence of the exothermic character of the electro-deposition process and the fact that newly formed surfaces tend to a configuration which reduces their internal stresses. (Great Britain) w. J. s. B. C. Banerjee 1964, 602-603.

and P. L. Walker,

635-648

249

34 643. How altitude effects forced air cooling requirements of electronic equipment. (U.S.A.) G. G. Gebert, Adv. Electron. Circuit Packaging, 3, (1963), 168-180.

Nature, 201 (4919), 8 Feb.

36.

33 635. Testing of high-duty carbided cathodes under vacuum. (rr.S.S.R.) S. I. Zilitinkevich and M. D. Gurevich, Priborostroyeniye, 5 (5), 1962, 3-5. 33 636. Electron gun design. K. E. Groves, Des. Electron., 1 (l), Oct. 1963, 18. 33 : 45 637. Electron beam welding. R. Gobel, Tech. Digest, 5 (9), Sept. 1963,7. 33 638. Grid characteristics in vacuum tubes fitted with oxide cathodes. (U.S.S.R.) Y. V. Mokvichev and P. V. Poshekhenov, Radiotekhnika, 5 (4), 1962, 519-520. 33 :45 639. Vacuum and non vacuum techniques for electron beam welding. (Great Britain) Anon., Machinery, 103 (2665), 11 Dec. 1963, 1328.

Drying, Degassing

and Concentration

36 : 40 644. Installation for the degassing of liquids and solutions. (U.S.S.R.) The article describes an installation for purifying liquids from paramagnetic oxygen dissolved in them. The degassing method used was “ freezing, evacuation, thawing “. The preliminary evacuation cycle to 2.1O-2 torr was carried out with a fore pump. The reduction to 1O-4 torr was monitored with a vacuum meter VT-2 in conjunction with an LT-2 transducer, and in the range of 1O-3 to 1O-6 torr an ionization manometer VI-3 with a VI-3 transducer were used. Cooling traps were inserted for the protection of the transducers of the vacuum meters and of the working fluid of the high-vacuum pump from contamination with the vapours coming off the samples under test. A basic diagram of the installation is attached. (Bibliography 8 items). (U.S.S.R.) L. M. F. M. Samigullin, and A. Sh. Agashev, Pribory i Teckh. Eksper., 1,1964, 224-225.

37.

Metallurgy,

Inorganic Chemistry, Chemistry

Analytica! 37 : 28

Continuous zone-refining apparatus.

34.

High Altitude and Space Technology

34 : 16 Adhesive behaviour of silicate powders in V.H. vacuum. See Abstr. No. 559. Emphasis on space cryogenics advances at Linde. 560.

34 : 17 See Abstr. No.

34 640. Friction and wear of diamond in high vacuum. (Great Britain) The authors’ experiments indicate that when diamond surfaces slide on one another in a high vacuum (or the order of lo-i0 torr), adsorbed surface films are removed and the naked crystal surfaces exposed. Under these conditions, the coefficient of sliding friction approaches unity against a value of 0.05 in air at atmospheric pressure. It is shown that arrival of a fraction only of a monolayer of gas on the surface suffices to produce a marked reduction in the coefficient and the dependence of friction on orientation of the crystal provides additional evidence of the may have extreme thinness of the film. These observations practical relevance to the operation of mechanisms intended to operate in outer space. Under these conditions “jewel bearings ” may show unforeseen high friction and wear. (Great W. J. S. Britain) F. B. Bowden and A. E. Hanwell, Nature, 201 (4926), March 28, 1964, 1279-1281. 34 641. Vacuum problems in the simulation of very high altitudes. D. J. Crawley, Sot. Environ. Engnrs., ll[ 1963, 15. 34 642. Device for creep tests at high temperatures in vacuum or an inert medium. (U.S.A.) (Trans. from the Russian). V. G. Govorkov et al., Zndustr. Lab., 29 (3), Oct. 1963, 375-377.

See Abstr. No. 606.

37 645. Some considerations on the results of the determination of hydrogen content in steel. (ZtaZy) The advantages and consequences deriving from the adoption of the hot vacuum extraction method at 600°C for the determination of the hydrogen content in steels are discussed. The number of data, obtained from such a method of gas analysis, has permitted a statistical investigation on the influence of hydrogen content before degassing on the post-degassing content ; on the influence of air moisture on the hydrogen content in steels and on the dependence of flakes from the hydrogen content. Some consideration is finally given to the methods adopted to avoid (Authors) flake formation in steels. (ZtaZy) G. Timo and U. Lodi, (In Italian).

Metallurgia

Ztaliana, 55, (1963), 560. 37

646. Vacuum exploded melt makes super pure metals. Anon., Engineering News, (136), 27 Feb. 1964, 10.

(U.S.A.)

37 647. The effect of vacuum degassing of cast iron melted under atmospheric conditions. (Germany) J. Thienne, Giesserei, 50 (20). 1963,602-609. 37 648. Hydrogen peroxide in the slow thermal reaction of hydrogen and oxygen. (Great Britain) The experiments were carried out at pressures between 300 and 400 torr at a temperature of 538°C in a vessel coated with boric acid. The authors conclude that hydrogen peroxide is not an essential active species in the hydrogen/oxygen reaction, but is formed by a heterogeneous process which is distinct from the (Great main overall reaction in which water is produced. w. J. s. Britain) M. Green and J. W. Linnett, Nature, 202 (4927), 4 April 1964, 80.