Creep and tensile properties of heavily drawn tungsten wire

Classified

abstracts

1301-1311

by a hawser and an extensible link equipped with connectors which effect sealing with the outlet of the tank tubular extension. This arrangement permits starting of the sheathing operation with the cable core under the vacuum conditions existing in the tank. The system may be used with either pre-impregnated or post impregnated cable cores. Pirelli General Cable Works Ltd, Brit Patent 1,062,444, Patent Abstr, 7 (15) part C, 17th April

molybdenum is described. For polycrystalline samples, room temperature tensile tests indicate greater ductility under lo-lo torr than under intermediate pressures up to and including atmospheric. In addition, tests conducted at 760 torr under atmospheres of air, nitrogen, and purified argon exhibited no apparent difference in mechanical properties. S Fuerstein and L Rice, AZME Tram, 236, 1966, 1677-1679.

1967, 2. 1306. Properties (USSR)

37. METALLURGY, CHEMISTRY

INORGANIC

CHEMISTRY,

ANALYTICAL

Solid state diffusion of antimony in germanium, from phase, in a vacuum furnace. See abstract number 1226.

37 :20 the vapour

37 : 28 Multipurpose vacuum furnace resistance heating. See abstract

with

induction

electron

beam

and

number 1248. 37 : 33

Effect of ultrasonic

vibrations on the structure of molybdenum jected to electron beam melting. See abstract number 1281.

sub-

37 : 33 The electron bombardment

smelting furnace of La Cie, Pechiney. See

abstract number 1284. 37 1301. Recent

developments

in

electron

beam

micro-machining.

of iron

purified

by electron-beam

The application of the electron beam as a production tool for micro-machining depends upon obtaining high working speeds and very good reproducibility. To demonstrate the progress achieved in recent years, the following examples are briefly described and illustrated: microbonding of semiconductors to metal in microelectronic components; drilling of holes in steel tubes, stainless steel foil and plastic foil; profile milling of a cross-piece in Teflon; and cutting of a maze-shaped resistance measurement component in copper foil. Brief reference is made to the importance of highlv a&&ate control of the relative positions of source and workpiece in the vacuum chamber. D Kiinig, Vakuum-Technik, 16 (3), March 1967, 48-52 (in German). 1302. Vacuum heat treating-a

boon for the common metals.

37 (USA)

Vacuum heat treating is being extended to the common metals since parts from a vacuum furnace need little or no finishing and have improved wear resistance. A continuous vacuum annealing line is capable of producing flat-rolled titanium coil in widths up to 48 inches. The continuous process applied to steel strip would eliminate pickling. Rapid quenching of batch-annealed component is made possible by a high vacuum gas quenching furnace. Die life appears to be sharply increased by vacuum heat treating. Vacuum brazing and heat treating of stainless steels and super alloys give better joints and increased toughness. Anon, Iron Age Metal Working Znt, 5, November 1966, 2.5-27. 37 1303. Vacuum degassing of stainless and alloy steels.

(USA)

A degassing unit of the vacuum lift type handles ladles of 30-70 tons capacity from 6 electric arc furnaces. The unit was chosen over other types available since it offers better alloying potential and better deoxidation and temperature control than other units for treating stainless steels. Designs of the steam ejector, heating system, air supply, ladle elevating system and other components are given briefly. W P Herbert, Iron Steel Eng, 43, 1966, 131-135. 37 1304. Vacuum degassed steels from the consumers viewpoint. (USA) Several systems have been developed to vacuum treat large heats of air-melted steel at much lower cost per ton than vacuum melting. It appears that vacuum degassing does produce cleaner steels with improved properties, particularly in regard to fatigue behaviour and ductility. A F Hoenie et al, Bateile Memorial Znst, Columbus, Ohio, No 219,

An electron beam zone melting refining technique was used to determine the mechanical and physical properties of several intermediate states. Iron, nickel, vanadium, niobium, molybdenum, tungsten and copper were studied and it was found that all metals except iron were obtained in the form of monocrystals after two passes. It was found that the residual electrical resistance of the purified iron was less than that of the initial iron. Data from elongation curves made at 300°K and 70°K were used to determine the yield point, ultimate strength, and the character of elongation of pure and refined iron rods. It was shown, that with a reduction in temperature, the yield point of refined iron increased to a lesser extent than that of the initial iron, and as the rate of deformation decreased, the difference between the yield point of refined iron at liquid nitrogen temperatures and at room temperature was sharply reduced. V I Shiryayev

and V D Pautov, Fiz Metal Metalloved, 20 (4), Ott Rep JPRS-37746; TT-66-34174 (Joint Publication Res Service, Washington, DC). 37 1307. Friction characteristics in vacuum, of single and polycrystalline aluminium oxide in contact with themselves and with various metals. (USA)

Friction experiments were conducted in vacuum with outgassed surfaces. Experiments were performed with single and polycrystalline Al,O, samples sliding on themselves and in contact with metals at a sliding velocity of 0.013 cm/set at loads to 1500 g, temperatures to 575°C and ambient pressures to lo-lo torr. D H Buckley, Am Sot, Lubrication Eng, Minneapolis Conf, Ott 1966, 28 pages. 1308. Creep and tensile properties (USA)

of heavily

effects

on

the

mechanical

behaviour

The effect of low pressures on the flow and fracture behaviour

drawn tungsten

37 wire.

A vacuum testing machine which can be used to determine mechanical properties of very fine wires at temperatures up 2500°F is described. It is shown that the tensile creep strengths drawn tungsten wires are considerably higher than those of crystallized bulk tungsten in the temperature range studied. B Harris and E G Ellison, ASM

1309. Stability (USA)

of refractories

Truns Quarterly,

during

vacuum

the to of re-

59, 1966, 744-754.

deoxidation

37 of steel.

The relative stability of acid alumina and basic refractories was determined by immersing refractory bricks in molten, 0.04 per cent carbon steel in a 500 lb induction furnace within a vacuum tank. The difference between the rate of pressure increase in the vacuum system while the brick was immersed and the rate before immersion, was determined. C E Osterholtz et al, Am Ceram Sot Bull, 45, 1966, 1067-1070. 37 1310. Fatigue apparatus

for extreme high vacuum.

(USA)

A constant amplitude, reverse bend stress fatigue testing device is described which permits simultaneous testing of up to 8 specimens at extremely low pressure levels below lo-“’ torr. The vibratory force was provided by an electromagnetic exciter with vibration frequencies in the range of 50-200 cps. Fatigue tests with llOO-H14 Al showed that a substantial increase in the cyclic fracture life was obtained in high vacuum as compared to the fatigue behaviour in unit atmosphere of air. The fatigue life improvement increases proportionally with the cyclic stress frequency. M E Read and M J Hordon, Rev Sci Znstrum, 38, 1967, 322-325.

1966, 27 pages.

428

37 melting.

1965, 566-569. English trawl,

(Germany)

1305. Ultrahigh vacuum molybdenum. (USA)

zone

37

37 of

1311. Largest titanium plant.

of

Titanium ingots, 1 m diameter and 3.5 m long, can be produced in a new melting plant with a fully automated high vacuum arc melting

(USA)