CAJ | 학술논문

采用化学气相沉积和原位合成工艺在 Cf/SiC 基体上制备了 Si/3Al2O3·2SiO2/La2Zr2O7新型环境障涂层（Environmental Barrier Coatings ， EBC），研究了 EBC 涂层在1300℃的抗热冲击性能。结果表明，涂覆Si/3Al2O3·2SiO2/La2Zr2O7涂层的Cf/SiC试样，在热冲击试验进行到121次时发生了过早剥落失效。试验过程中，3Al2O3·2SiO2中间层内的Al元素发生外扩散并在面层中发生反应生成LaAlO3，La2Zr2O7在1300℃高温热冲击环境下发生烧结和粉化，以及由于热膨胀系数差异造成的 EBC 涂层内残余应力的产生均是导致EBC涂层过早剥落失效的主要原因。
채용화학기상침적화원위합성공예재 Cf/SiC 기체상제비료 Si/3Al2O3·2SiO2/La2Zr2O7신형배경장도층（Environmental Barrier Coatings ， EBC），연구료 EBC 도층재1300℃적항열충격성능。결과표명，도복Si/3Al2O3·2SiO2/La2Zr2O7도층적Cf/SiC시양，재열충격시험진행도121차시발생료과조박락실효。시험과정중，3Al2O3·2SiO2중간층내적Al원소발생외확산병재면층중발생반응생성LaAlO3，La2Zr2O7재1300℃고온열충격배경하발생소결화분화，이급유우열팽창계수차이조성적 EBC 도층내잔여응력적산생균시도치EBC도층과조박락실효적주요원인。
A new environmental barrier coating (EBC)system including Si/3Al2O3·2SiO2/La2Zr2O7 was investigated in this study. Si and mullite (3Al2O3·2SiO2)bond coating was firstly deposited on top of Cf/SiC substrate by chemical vapor deposition(CVD), and then La2Zr2O7 as one top coating was fabricated by in-situ synthesis.High temperature thermal shock behavior of EBC system was tested at 1300 ℃.The results indicate that the degradation of the coatings occurs after exposure of 121 cycles.The Al element contained in the middle layer diffuses outward to La2Zr2O7 top coating and then one new phase of LaAlO3 is formed,and the early sintering and increment of porosity within La2Zr2O7 at 1300℃,and the residual stresses induced by the mismatch of thermal expansion coefficients among Si,mullite and La2Zr2O7 are the primary factors leading to the spallation failure of EBC.