电弧喷涂纳米结构涂层的组织与磨损性能

Microstructure and Wear Properties of Nanostructured Coatings Prepared by Wire Arc Spray

基于机器人自动化高速电弧喷涂技术在45#钢基体上制备了铁基纳米结构涂层.研究了纳米结构涂层在不同磨损速度、不同载荷下的磨损行为,并利用3Cr13涂层进行对比试验.采用扫描电镜、能谱分析仪,透射电镜和X射线衍射仪等设备对涂层的组织结构进行了表征,利用纳米压痕仪对涂层的力学性能进行了分析.结果表明:涂层的组织主要由非晶相和α(Fe,Cr)相纳米晶组成;平均尺寸为46nm的α(Fe,Cr)相纳米晶均匀分布于非晶基体内.涂层的组织均匀,结构致密,平均孔隙率含量为1.7%.纳米结构涂层具有较高的显微硬度;随着磨损速度升高,载荷增加,纳米结构涂层的磨损量也随之增加.纳米结构涂层具有良好的耐磨性,同一磨损条件下,其相对耐磨性为3Cr13涂层的2.6倍.纳米结构涂层主要磨损机制为脆性断裂机制.

This paper investigated the effects of wear paramaters,such as sliding speed and load,on the wear properties of Fe-based nanostructured coating. A series of Fe-based nanostructured coatings were prepared by using wire arc spray. The microstructure of the coating was characterized by SEM,EDAX,XRD and TEM. The mechanical properties of the coating were measured by nanoindention. The wear tests of coatings were conducted on a MM200 wear tester. The microstructure of the coating consisted of amorphous phase and nanocrystalline （Fe,Cr） phase. The nano-grains with an average size of 46 nm were homogenously dispersed in an amorphous phase matrix. The coating was nearly full-densed with a porosity of 1.7% and high hardness. With the increase of sliding speed and load,the wear mass of the coating increased. The nanostructured coating had excellent wear resistance,i.e. the nanostructured coating was 2.6 times as high as that of the 3Cr13 coating. The failure mechanism of the coatings was brittle fracture.