激光熔覆IMC涂层的热疲劳性能

研究了激光熔覆和Ｎｉ－Ａｌ合金涂层及（Ｎｉ－Ａｌ）＋ＷＣ复合涂层的热疲劳性能。结果表明，涂层疲劳损伤形式为沿晶应力（氧化）腐蚀。腐蚀产物为Ａｌ２Ｏ３。每次热循环后，熔覆层中的最终残余应力是残余热应力和相变应力共同作用的结果。由于复合涂层中的残余应力为压应力，而合金涂层中的残余应力为拉应力，因此前热疲劳性能优于后者。

Thermal Fatigue Properties of Laser Cladded IMC Coatings

Thermal fatigue properties of laser cladded Ni Al alloy coating and (Ni Al)+WC composite coating have been investigated. The damage mechanism of coatings tested is intercrystalline (oxidation) corrosion under stress. The corrosive product is Al 2O 3. After each thermal cycle, the final residual stress in laser cladded coating is as a result of the common action by thermal stress and phase transformation stress. The residual stress in composites coating is compressive stress but that in alloy coating is tensile stress, so the thermal fatigue properties of composite coating are superior to those of alloy coating.