石墨烯改性316L不锈钢表面熔覆涂层的组织与性能

Microstructure and properties of clad coating modified by graphene on 316L stainless steel surface

利用感应熔覆技术在316L不锈钢表面采用预置涂层法成功制备了不锈钢和石墨烯混合粉末的高性能涂层。利用光学显微镜、扫描电镜、显微硬度仪和XRD等手段对其涂层性能进行了测试及表征。结果表明,感应熔覆后,试样横截面组织可以分为熔覆涂层、过渡区、基体,整个横截面没有气孔、裂纹等缺陷,基体与涂层结合良好。随着石墨烯含量的增加,晶粒愈加细小,组织愈加致密。表面形貌分析表明,石墨烯如枝晶状蔓延,包裹住熔融凝固后的不锈钢粉末。石墨烯含量在0.1%～0.4%之间时,涂层硬度值缓慢增加。物相分析得出熔覆涂层有硬质相析出。

High-performance coating with mixed powder of stainless steel and graphene was successfully prepared on the surface of 316 L stainless steel by induction cladding technology. Properties of the coating were tested and characterized by means of optical microscope,scanning electron microscope,microhardness tester and XRD. The results show that microstructure of the sample cross-section consists of clad coating,transition zone and matrix. The whole cross-section has no porosity,cracking or other defects,and the matrix is well combined with the coating. With the increase of graphene content,the grain in the coating is finer,and the microstructure is more compact. The analysis of surface morphology shows that the dendritic graphene spreads and wraps solidified stainless steel powder. When graphene content is between 0. 1%-0. 4%,the hardness values of the coatings increase slowly. The phase analysis shows that the clad coating precipitates a hard phase.