Surface Microstructure and High Temperature Oxidation Resistance of Thermal Sprayed NiCoCrAlY Bond-Coat Modified by Cathode Plasma Electrolysis

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2017,（9）
• 页码范围: 1055-1060
• 页数: 6页
• 语种: 英文

摘要

The surface properties of the air-plasma sprayed bond-coat have been modified by cathode plasma electrolysis (CPE).After modification,a re-melted layer without obvious pores and oxide stringers is formed,the gain size of re-melted layer is approximately 80-120 nm.It is shown,from cyclic oxidation at 1100 ℃,that a thin oxide scale mainly composed of α-Al2O3 has been formed on the modified bond-coat and the oxidation resistance of the modified bond-coat has been significantly improved.Such beneficial result can be attributed to following effects:during CPE process,the plasma discharges with high temperature take place on the bond-coat surface.With plasma discharge treatment,the surface is melted and quickly re-solidified,the grain size decreases,and the pores and oxide stringers disappear.During cyclic oxidation,owing to the above modification of surface properties,the critical content of Al for selective oxidation is significantly decreased.Therefore,a continuous Al2O3 scale is formed.