EFFECT OF HIGH-ENERGY BALL-MILLING ON STRUCTURE AND SOME PROPERTIES OF POWDER TUNGSTEN ALLOYS

The effect of mechanical activation in high-energy ball mill on the structure, and behavior upon consolidation and sintering as well as on the structure and properties of the sintered alloys was studied on powders of tungsten and its alloys with 5 wt.% Re and with less-than-or-equal-to 8 vol.% of Y2O3 and HfC. The mechanical hardening of the powder particles upon the activation results in more uniform distribution of alloying elements in solid solution, leads to accelerated grain growth during the sintering, and improves the mechanical properties of the powder tungsten alloys. The alloys sintered from these powders surpass the conventional powder alloys in strength and plasticity and also are as good as the vacuum-melted alloys for strength but surpass them in plasticity at the temperatures of the ductile-brittle-transition range.