TiB_2陶瓷颗粒增强电弧喷涂涂层滑动磨损性能的研究

Study on Sliding Wear Resistance of Arc Sprayed Coatings with TiB_2 Ceramic Phase

采用电弧喷涂含TiB2陶瓷粉末的粉芯丝材,在低碳钢基体上制备了NiCr-TiB2和304L-TiB2金属基复合涂层,在摩擦磨损试验机上研究了按环/块线接触方式作往复运动条件下无润滑时室温下的摩擦磨损性能,利用光学显微镜、扫描电子显微镜和X射线衍射仪对涂层的显微组织结构、磨损表面及其相组成进行分析。结果表明,涂层的相对耐磨性能远高于碳钢基体,约为9到11.5倍。304L-TiB2涂层的低磨损率除了与硬质相有关,还和涂层具有较高的硬度有关。NiCr-TiB2涂层的耐磨性能好,细小的TiB2陶瓷相在局部涂层中连成网状,与基体结合良好,有效提高了涂层的磨损性能。

Core line sprayed by arc spraying with TiB2 ceramic power,and NiCr-TiB2 and 304L-TiB2 metallic matrix composite coating were prepared under the condition of low carbon steel basic body.The character of those under the condition of no lubricant and normal temperature were studied with ring-block line connecting way by using attrition testing machine Microstructure of arc sprayed NiCr-TiB2,the form mechanism of composite coatings and 304L-TiB2 coatings were investigated by optic microscope,scan electron microscope（SEM） and transmission electron microscope（TEM）.Experimental results showed the TiB2-reinforced coatings present higher wear resistance than that of the low carbon steel about 9 to 11.5 times.Owing to the presence of hard phase and higher hardness,304L-TiB2 coating has low wear rate.Fine TiB2 ceramic phase bonded with metallic matrix in the NiCr-TiB2 coating connected each other and formed reticular in some zones,which efficiently improved the wear resistance of coating.