Study on the plasma erosion resistance of ZrO_(2p)(3Y)/BN-SiO_2 composite ceramics

摘要

ZrO_(2p)(3Y)/BN-SiO_2 composite ceramics were prepared by hot pressed sintering. The Kr plasma was incident normally to the sample surface to measure the plasma erosion resistance, and XRD, TEM, SEM were used to characterize the phase composition and morphology of composite ceramics before and after Kr plasma erosion. The composites were composed of h-BN, amorphous SiO_2, m-ZrO_2 and t-ZrO_2, which keep stability in the process of Kr plasma sputtering. Two kinds of zirconia phases (t-ZrO_2, m-ZrO_2) and lamellar h-BN evenly distributed in ZrO_(2p)(3Y)/BN-SiO_2 composite ceramics, and the lath microstruc-tures were observed in m-ZrO_2 particles. The plasma erosion resistances of ceramic composites increase significantly with the increase of ZrO_2 content. Pits with diameter sizes of several micrometers were observed on the surface of composites after plasma sputtering, which indicate that one or several grains are sputtered out during the plasma sputtering process. The edges of the grains become smoother for the preferential sputtering to the sharp edge of the grains during plasma sputtering.