ZrB2-SiC-ZrC coating on ZrC ceramics deposited by plasma spraying

The ZrB2-SiC-ZrC coating free of adhesion layer was successfully prepared by plasma spraying. Fine ZrB2-SiC-ZrC sprayed composite powders were pre-synthesized by muti-step hot pressing. The X-ray diffraction (XRD) analysis showed that as-sprayed coating was primarily composed of ZrB2-SiC-ZrC and a small quantity of SiO2 and ZrO2, which corresponds with the composition of spraying composite powders. The microstructure of the coating exhibited the characteristics of stacking of fully melted and partially melted particles. The coating was continuous and well bonded with ZrC substrate without adhesion layer. However, a few pores were found in the sprayed composite coating, which was attributed to incomplete melting of some of ZrB2-SiC-ZrC composite powders during plasma spraying.

通过等离子喷涂成功制备了无粘结层的ZrB₂ - SiC - ZrC涂层。通过多步热压预先合成了精细的ZrB₂ - SiC - ZrC喷涂复合粉末。X射线衍射（XRD）分析表明，喷涂后的涂层主要由ZrB₂ - SiC - ZrC以及少量的SiO₂和ZrO₂组成，这与喷涂复合粉末的成分相符。涂层的微观结构呈现出完全熔化和部分熔化颗粒堆积的特征。涂层连续，与ZrC基体结合良好，无粘结层。然而，在喷涂复合涂层中发现了一些孔隙，这是由于在等离子喷涂过程中一些ZrB₂ - SiC - ZrC复合粉末未完全熔化所致。