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目的 提高316L不锈钢表面的硬度及耐磨性能.方法 采用磁控溅射法在316L不锈钢表面制备Ni-Ti合金薄膜,并通过纳米压入法对316L不锈钢表面、Ni-Ti合金薄膜和Ni-Ti合金材料的力学性能进行测试,分析不锈钢基Ni-Ti薄膜的耐磨性能.应用有限元反演分析方法求解基体和薄膜的弹塑性幂本构关系.结果 316L不锈钢与Ni-Ti合金抵抗载荷的能力较弱,但316L不锈钢表面Ni-Ti薄膜抵抗外加载荷的能力较强,且抵抗塑性变形的能力得到强化.Ni-Ti薄膜、316L不锈钢基体和Ni-Ti合金的硬度分别为8.2795、5.2405、2.9498 GPa,薄膜的硬度明显大于基体和Ni-Ti合金,说明Ni-Ti薄膜使得316L不锈钢的耐磨性显著提高.薄膜的弹性性能较基体与Ni-Ti合金有明显优势.为研究薄膜的弹塑性性能,建立ABAQUS二维有限元模型,考虑Berkovich压头和试样之间摩擦系数为0.16,通过纳米压入实验和有限元分析的对比,反演分析分别计算得到基体和薄膜的特征应力、特征应变、应变强化因子,继而确定初始屈服应力,得到Ni-Ti合金薄膜和316L不锈钢基体的弹塑性幂本构关系.结论 Ni-Ti薄膜具有良好的力学特性,使316L不锈钢表面的硬度显著提高,因此有效提高了不锈钢的耐磨性能.

The work aims to improve the hardness and abrasion resistance of 316L stainless steel surface.Ni-Ti alloy film was prepared on the surface of 316L stainless steel substrate by adopting magnetron sputtering method.Nanoindentation tests were carrried out on the surface of 316L stainless steel substrate,Ni-Ti alloy film and Ni-Ti alloy to test their mechanical properties and analyze abrasion resistance of Ni-Ti film.Meanwhile,finite element modeling (FEM) was adopted to establish the elastic-plastic exponent constitutive relation between the substrate and Ni-Ti film.316L stainless steel material and Ni-Ti alloy exhibited weaker load-carrying capability while 316L stainless steel coated with Ni-Ti film exhibited better load-carrying capability and plastic deformation resistance.Hardness of Ni-Ti film,316L stainless steel substrate and Ni-Ti alloy were 8.2795,5.2405 and 2.9498 GPa,respectively.Hardness of the film was significantly greater than that of the substrate and Ni-Ti alloy,indicating that abrasion resistance of 316L substrate was greatly improved by coating with Ni-Ti film.Elastic property of film of the film was obviously superior to that of the substrate and Ni-Ti alloy.An ABAQUS 2D model was established to study elastic property of the film.Considering coefficient of friction between sample and Berkovich indenter as 0.16,nanondentation test,finite element analysis and inverse analysis were performed to calculate representative stress,representative strain,strain-hardening exponent and further the value of initial yield stress,Then the elastic-plastic exponent constitutive relation between the substrate and Ni-Ti film was established.Ni-Ti film is of excellent mechanical property,which can effectively improve the surface hardness and abrasion resistance of stainless steel.