Spark plasma sintering of tungsten alloyed with tantalum

Abstract Tungsten is a typical refractory metal and is a promising plasma-facing material for the future fusion reactors. The problem with tungsten is its high brittle-ductile transformation temperature, which limits the range of industrial applications of tungsten. This problem could be tailored by enhancing the extrinsic and intrinsic plasticity of tungsten via processing and alloying, respectively. This study aimed to explore both aspects and investigate how tantalum addition, powder handling, and Spark Plasma Sintering (SPS) conditions affect densification, microstructure, and flexural strength in large 50 mm W–6Ta compacts. The storage and handling of the powders in the air revealed problems with tantalum oxide formation during the sintering that affected the mechanical properties despite the formed tantalum-tungsten solid solution during sintering and the limited grain size refinement.