The morphology and arrangement of bubbles in the heat treated, doped tungsten wire have been observed by means of optical and scanning electron microscopies. Also, the study on the deformation texture in drawn tungsten wires was made by neutron diffraction method.
As the heating rate was increased, tubular bubbles in the doped wire had become changed into arrays of fine, spherical bubbles, resulting in the elevation of bend strength and hardness. Particularly, when the cyclic heating was applied, the treated wires have exhibited better mechanical properties in comparison with the normally heat treated up to 1800℃. Beyond this temperature, however, the reversal was occurred.
It was found that the drawn wire had a strong texture with ＜110＞+＜320＞ as a major component plus ＜531＞,＜421＞, and ＜310＞ as minor components.
