摘要
The stratified gradient thermal barrier coatings (TBCs) were obtained by laser cladding of ZrO 2 and NiCoCrAlY mixture powder. The coatings were four layer structure: cellular dendritic ZrO 2, dense ZrO 2, Ni based alloy bonding coating and substrate. The formation of the stratified TBCs was attributed to the insolubility of ZrO 2 in the Ni based alloy and the lower density of ZrO 2 than that of Ni based alloy when both of them were in melted condition. The formation of two layered ZrO 2 was related to the presence of Al in the Ni based alloy, i) Al could be preoxidized into Al 2O 3 that could be segregated in the grain boundaries of ZrO 2 during solidification process; ii) Al could be partially preoxidized into Al 2O 3, then Al and Al 2O 3 could be segregated simultaneously at the grain boundaries of ZrO 2 during solidification process. Two formation processes were presented.
The stratified gradient thermal barrier coatings (TBCs) were obtained by laser cladding of ZrO2 and NiCoCrAlY mixture powder. The coatings were four-layer structure: cellular dendritic ZrO2, dense ZrO2, Ni-based alloy bonding coating and substrate. The formation of the stratified TBCs was attributed to the insolubility of ZrO2 in the Ni-based alloy and the lower density of ZrO2 than that of Ni-based alloy when both of them were in melted condition. The formation of two-layered ZrO2 was related to the presence of Al in the Ni-based alloy, i) Al could be preoxidized into Al2O3 that could be segregated in the grain boundaries of ZrO2 during solidification process; ii) Al could be partially preoxidized into Al2O3, then Al and Al2O3 could be segregated simultaneously at the grain boundaries of ZrO2 during solidification process. Two formation processes were presented.
出处
《中国有色金属学会会刊：英文版》
CSCD
2000年第1期92-93,共2页
Transactions of Nonferrous Metals Society of China
