科研之友
微信
新浪微博
Facebook
分享链接
摘要
The Al2O3-Y2O3 system composite coatings were prepared by plasma spraying Al2O3-Y2O3 composite powders with or without TiO2 addition. The effects of TiO2 on the microstructure and properties of the Al2O3-Y2O3 coatings were investigated. The results show that the composition of the composite powders had great influence on their microstructure evolution. The Al2O3-Y2O3 coatings were composed mainly of alpha-Al2O3 and c-Y2O3. There were amorphous phase, Y3Al5O12 (YAG) phase and Y4Al2O9 (YAM) phase formed in the Al2O3-Y2O3 coating. The content of Y3Al5O12 in the Al2O3-Y2O3-TiO2 coating increased with addition of 2 wt% TiO2, and the content of Y4A1209 and amorphous phases decreased correspondingly. There was no Y3Al5O12 formed in the Al2O3-Y2O3TiO2 coatings with further increasing of TiO2, while the content of amorphous phase increased. The micro hardness of the Al2O3-Y2O3-TiO2 coating was improved with the addition of 2 wt% TiO2, which was attributed to its lower porosity, more uniform microstructure, more YAG phase, and less amorphous phase. The microhardness of the AAl(2)O(3)-Y2O3-TiO2 coatings decreased significantly with further increasing of TiO2 due to the significant decrease of YAG phase and the increase of the amorphous phase. The Al2O3-Y2O3-TiO2 coating with addition of 2 wt% TiO2 possessed higher toughness, adhesive strength and wear resistance compared with the Al2O3-Y2O3 coating, which was due to its lower porosity, smaller and spherical pores, and more YAG phase.
