Effect of Ball Diameter on Mechanical Alloying Process for the Production of Dispersion Strengthened Tungsten

Abstract

Tungsten is candidate material for plasma facing armor. In our initial study, to improve the plasma facing tungsten on fusion divertor, a new oxide dispersion strengthened tungsten (ODS-W) has been developed using by REDOX (oxidation-reduction reaction) process between W and TiC, including titanium oxide as strengthening nano-particles in matrix, fabricated by mechanical alloying (MA)-hot isostatic pressing (HIP), which can inhibit the decrease of mechanical property even after recrystallization occurs. Our past studies showed that the condition of MA process affects the mechanical and the thermal properties of the products. In the present study, the optimal ball size to be used in the MA process of preparing ODS-W has been proposed by investigation of the relationship between different ball sizes and the MA effect, focusing the optimization of manufacturing process for DS-W. The evolutions of the lattice constant and microstructure were shown to indicate the progress of mechanical alloying. The effect of the ball size was interpreted as that of collision energy delivered by the weight of MA balls.