激光熔覆功率对原位合成TiB/TiN涂层组织和摩擦性能的影响

Effect of Laser Density on Microstructure and Wear Performance of In-situ Synthesized TiN-TiB/Ti Based Composite Coating by Laser Cladding

以光学显微镜(OM)、X射线衍射分析(XRD)、扫描电子显微镜(SEM)和电子探针(EPMA)方法分析涂层相组织结构和显微形貌,采用硬度测试仪及滑动磨损机测试涂层硬度及耐磨性能.结果表明,涂层中原位合成了TiB和TiN强化相颗粒,分别呈现针棒状形貌组织和等轴晶形貌组织;激光功率对组织形貌影响较大,随着激光功率的提高,熔覆层的硬度和耐磨性能呈上升的趋势;母材的磨损机制主要为疲劳磨损,而熔覆层金属的磨损主要由疲劳磨损和磨粒磨损共同作用,其中磨粒磨损占主体作用.

The phase structure,microstructure,microhardness and wear performance of the composite clad layer are analyzed by optical microsccopy（OM）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,electron probe microanalyzer（EPMA）micro-hardness tester and wear testing.The reasult indicates that TiN and TiB are in situ synthesized in the cladding layer and are compared with needle platelet and equiaxed type microstructures.Laser density plays an important role in microstructures.With the increase of laser density,microhardness and wear resistance rise,the main mechanism of the sbustrate is severe adhesive wear mechanism.However,the wear mechanism of cladding layer is a combination of adhesive and abrasive wear characteristics,and the abrasive wear characteristics is the main wear mechanism.