Oxidation behavior of thermally sprayed Mo-Si based composite: Effect of metastable phase, porosity and residual stress

Constituent phases, porosity and residual stress are significant factors influencing the performance of two-dimension (2D) structural components. In present study, these factors with respect to thermally sprayed MoSi₂ based composite were elaborately adjusted through plasma spraying power to investigate the oxidation behavior in medium temperature range of 400–900 °C. By increasing the operation powers, the improved melting degree of feedstock led to the increased metastable phases and the decreased porosity in the MoSi₂ based composite but it did not remarkably affect the residual stress distribution. After the analysis on the medium-temperature oxidation, it can be concluded that the metastable phases and the porosity were principally responsible for the enhanced oxidation resistance of the MoSi₂ based composite. The thermal-sprayed 2D MoSi₂ based composites with large amounts of β phases and low porosity can achieve the outstanding oxidation resistance in medium temperature range.