等离子喷涂NiCoCrAlYTa-Al2O3复合涂层的高温摩擦性能

采用大气等离子喷涂(APS)技术在0Cr25Ni20奥氏体不锈钢表面制备了NiCoCrAlYTa-Al₂O₃涂层,并对该涂层的显微组织、相组成、显微硬度以及在500 ℃时涂层的高温摩擦性能进行了研究。结果表明,NiCoCrAlYTa-Al₂O₃涂层呈典型层状结构,各层间结合良好。涂层内存在大量微孔隙,且硬质相与软质相分散分布,有效抑制了高温磨擦过程中裂纹的产生和扩展,涂层耐磨性能较奥氏体不锈钢基体材料显著提高。高温磨损过程中,涂层表面形成氧化产物,起到固体润滑作用。NiCoCrAlYTa-Al₂O₃涂层的磨损失效形式主要是磨粒磨损、疲劳磨损和粘着磨损。

High temperature friction properties of NiCoCrAlYTa-Al2O3 composite coating by atmospheric plasma spraying

NiCoCrAlYTa-Al₂O₃ composite coatings were prepared on 0Cr25Ni20 austenitic stainless steel by atmospheric plasma spraying (APS). The microstructure, phase composition, micro-hardness and high temperature(500 ℃) friction properties of the coatings were studied. The results show that the NiCoCrAlYTa-Al₂O₃ coating has typical layered microstructure and good bonding among layers. There are a large number of micropores in the coating, and the hard phase and the soft phase are dispersedly distributed, which effectively inhibits the generation and propagation of cracks during high temperature wear process. The wear resistance of the coating is significantly better than that of the austenitic stainless steel. During the high temperature wear process, oxidation products are formed on the coating surface, which actassolid lubrications. The wear failure modes of the NiCoCrAlYTa-Al₂O₃ coating are abrasive wear, fatigue wear and adhesion wear.