Microstructure and properties evolution of plasma sprayed Al2O3-Y2O3 composite coatings during high temperature and thermal shock treatment

• 作者: Xingyu Wang Xiaolong Wang Xiaowen Sun Yong Yang Chen Zhang Yuduo Ma Yuhang Cui Yanchun Dong Dianran Yan You Wang
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: ADVANCED RARE EARTH MATERIALS
• 页码范围: 718-727
• 页数: 10页
• 语种: 英文

摘要

Al2O3-Y2O3 composite powder with TiO2 additive was plasma sprayed to prepare Al2O3-Y2O3 composite coatings.The microstructure and properties evolution of the Al2O3-Y2O3 coatings during high temper-ature and thermal shock resistance were investigated.The results show that the microstructure of the Al2O3-Y2O3-TiO2 coating is more uniform than that of the Al2O3-Y2O3 coating.Meanwhile,amorphous phase is formed in the two coatings.The Al2O3-Y2O3(-TiO2) coatings were heat treated for 2 h at temperatures of 800,1000 and 1200 ℃,respectively.It is found that the microstructure and properties of the two coatings have no obvious change at 800 ℃.Some of the amorphous phase is crystallized at 1000 ℃,and meanwhile Y2O3 and Al2O3 react to form YAG phase and YAM phase.At 1200 ℃,all of the amorphous phases are crystallized.After heat treatment,the microhardness of the two coatings is increased.The thermal shock resistance of the Al2O3-Y2O3 system coatings can be improved by using TC4 titanium alloy as substrate and with NiCrAlY bonding layer.Moreover,the Al2O3-Y2O3-TiO2 coating ex-hibits better thermal shock resistance due to the addition of TiO2.