摘要
利用自蔓延高温合成结合准热等静压技术(SHS/PHIP),在H13钢表面制备了Ti C/Ni梯度功能涂层,采用自制热疲劳试验设备对涂层进行了600次热疲劳循环试验。采用SEM/EDS对涂层微观组织进行观察。结果表明,涂层裂纹萌生于表面层和中间层的孔洞尖端和缺陷处,25℃和100℃涂层的裂纹垂直于界面扩展到过渡层。25℃涂层在过渡层发生脱落,100℃涂层在过渡层呈龟裂状,200℃和300℃涂层裂纹垂直于界面扩展到基体表面终止。表面层和中间层裂纹扩展发生在Ti C晶粒内,属于典型脆性断裂特征的穿晶断裂。
The TiC/Ni functionally gradient coatings on HI3 steel surface were prepared by self-propagating high temperature synthesis and pseudo hot isostatic pressing （SHS/PHIP）. The 600 thermal fatigue cycle tests were carried out the coating by the self-made thermal fatigue test equipment The coating microstructures were characterized by SEM/EDS, The results show that the cracks initiate at the tips and defects of the surface layer and interlayer, and propagate to the transitional layer of 25℃ and 100℃ coatings perpendicular to the interface, 25℃ coating falls off in transition layer, 100℃ coating appears transition layer cracking. The cracks of 200℃ and 300℃ coatings propagate to the substrate interface. The crack propagation occurs within the TiC grains of the surface layer and interlayer, which belongs to the typical characteristics of brittle fracture of transgranular fracture.
出处
《铸造技术》
CAS
2018年第1期189-193,共5页
Foundry Technology
基金
国家自然科学基金资助项目(51375353)
