摘要
采用Ｕｄｄｅｈｏｌｍ法进行了激光熔覆钴基合金层的热疲劳试验，观察了热疲劳裂纹萌生及扩展特性。结果表明，热疲劳裂纹易于在脆性相及枝晶间形核，并优先在枝晶间扩展。控制脆性相的生成，适当粗化枝晶及减小枝晶区间，有利于提高激光熔覆合金层的热疲劳抗力。
The influence of microstructure on the thermal fatigue of two cobalt-based coatings bylaser cladding is investigated by the Uddeholm method.The results show that the thermal fa-tigue cracks are liable to nucleate at interfaces between the brittle phases and dendrites andthen to propagate interdendritically.The thermal fatigue life of the coating can be significant-ly lengthened by reducing the brittle phase within the primary phase and eutectic structureby proper coarsening of the dendrites as well as by a smaller number of interdendritic sites.
出处
《华中理工大学学报》
CSCD
北大核心
1995年第12期86-88,共3页
Journal of Huazhong University of Science and Technology
基金
湖北省自然科学基金
