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利用6kW光纤激光器,采用预置粉末法在304不锈钢表面激光熔覆制备Fe17Mn5Si10Cr5Ni记忆合金涂层。利用扫描式电子显微镜、X射线衍射仪及往复摩擦试验仪等设备对涂层的微观组织、相组成进行研究,对涂层及基材的耐磨性能、接触疲劳特性进行对比分析,并利用小孔法对试样的残余应力进行测量。结果表明:记忆合金涂层自界面到顶端分别由平面晶、包状晶、柱状晶组成;涂层磨损机制为磨粒磨损,基材磨损机制为粘着磨损,涂层磨损量仅为基材磨损量的三分之一,耐磨性优于基材;涂层接触疲劳强度优于基材;熔覆试样残余应力较基材低。应力诱发γ→ε马氏体相变是涂层力学性能优异的根本原因。
The Fe17Mn5Si10Cr5Ni memory alloy coating was prepared by laser cladding on the surface of 304 stainless steel with a 6kW fiber laser. Using scanning electron microscopy, X-ray diffraction and reciprocating friction tester and other equipment on the microstructure and phase composition of the coating to study the wear resistance of the coating and the substrate, contact fatigue characteristics were compared, and the use of small Hole method to measure the residual stress of the sample. The results show that the memory alloy coating consists of plane crystal, encapsulated crystal and columnar crystal respectively from the interface to the top. The abrasion mechanism of the coating is abrasive wear, the wear mechanism of the substrate is adhesive wear, the abrasion loss of the coating is only the substrate wear One third of the wear resistance is better than that of the substrate. The contact fatigue strength of the coating is better than that of the substrate. The residual stress of the cladding sample is lower than that of the substrate. Stress induced γ → ε martensitic transformation is the fundamental reason for the excellent mechanical properties of the coating.