The effect of LaSi₂ content on the powder characteristics and coating structure of ZrB₂-SiC

To investigate the effect of LaSi₂ content on the properties of ZrB₂-SiC composite powder and coatings, different amounts of LaSi₂ were added to the ZrB₂-SiC system. The composite powders were prepared using the induction plasma spheroidization process, and the coatings were fabricated using atmospheric plasma spraying. Results showed that LaSi₂ significantly improves the density of both the powder and the coatings. As LaSi₂ content increase to 15 vol%, the density of the powders increases to 2.75 g/cm³ and the porosity of the coatings decreases to 6.92 %. Our results suggest that LaSi₂ can fully melt in the plasma jet field and act as a sealing phase to heal pores, thereby improving the performance of both the powders and subsequently, the coatings.