On Rolling Workability of Pure Tungsten Single Crystals with (110) [001] and (001) [110] Orientations at Room Temperature∼200°C

Abstract

Pure tungsten single crystals with (110) [001] and (001) [110] orientations were grown by the technique of electron-beam zone-melting. Deformation by rolling in these orientations was studied in the temperature range between room temperature and 200°C. The main experimental results obtained were as follows:
(1) The (001) [110] crystal showed good ductility on rolling above 100°C, but the (110) [001] crystal was fractured in a brittle manner even at 200°C.
(2) An abnormal widening which has not been observed in crystals of pure iron and 3% Si–Fe on rolling at room temperature was found in the (001) [110] crystal rolled at 200°C.
(3) The (110) [001] crystal rotated about the transverse direction as in a 3% Si–Fe crystal with the same orientation. However, the degree of crystal rotation by rolling was found to be smaller at least up to 50% reduction, as compared with that of the 3% Si–Fe crystal.
The above phenomena are discussed relating to the easiness of the multiple slip in tungsten crystals.