Preparation of refractory Ta-10 W alloy powder by plasma rotating electrode process

Abstract

How to prepare high-performance and fine powder suitable for additive manufacturing (AM) is crucial to the deep utilization of Ta-10 W alloy. In this paper, refractory Ta-10 W alloy powder was prepared via the plasma rotating electrode process (PREP) technology, and the atomization process was numerically reconstructed using the computational fluid dynamics (CFD) method. Comprehensive characterization of the powder properties was performed. And the influences of key operating parameters on the size and properties of Ta-10 W alloy powder were systematically analyzed. Mechanism insights into parameter effects on atomization behavior and resultant powder properties were elucidated. Results demonstrate that high-performance Ta-10 W alloy powder with high sphericity, good surface quality, low oxygen content, freedom from hollow spheres and fine powder size suitable for additive manufacturing is successfully prepared. When the rotating speed increases from 21,000 rpm to 25,000 rpm or the current decreases from 2600 A to 2200 A, the size of the Ta-10 W alloy powder decreases. The liquid film disintegration mode during the atomization process is mainly liquid ligament disintegration. Increasing the rotating speed and decreasing the current will lead to a decrease in the thickness of the liquid film and the diameter of the liquid ligament, thereby reducing particle size. A high rotating speed, i.e., 25,000 rpm and a low current, i.e., 2200 A can be employed to obtain Ta-10 W alloy powder with a small size.