Synthesis and Characterization of W/SiC Compositionally Graded Film as a Potential Plasma-facing Material

Tungsten (W) is a promising plasma-facing material due to its low physical and chemical sputtering yield but suffers from embrittlement and blistering. A potential alternative is silicon carbide (SiC) due to its low neutron activation and favorable thermomechanical properties but is more prone to sputtering. In this work we explore synthesis and benefits of W/SiC compositionally graded films given W and SiC have a good mechanical and chemical compatibility owing to their similar coefficients of thermal expansion and stable binary compounds. Preliminary W/SiC coatings have previously been synthesized and exposed using the DiMES apparatus in DIII-D. The present study improves upon the coating deposition process for synthesis of W/SiC films. Microstructural images are obtained via SEM and chemical composition is qualitatively assessed by electron energy dispersive x-ray spectroscopy line scans across the film. Finally, density functional theory calculations are performed to assist in predicting the stability of various structures/phases in the composition regimes of synthesized W/SiC samples.