摘要
采用纳米压痕仪和曲率半径为20μm的金刚石球形压头研究了40Cr基体和CrNx薄膜的径向纳动行为,并探讨其损伤机制.结果表明:CrNx薄膜能够提高40Cr基体的抗压性能,提高其接触刚度,降低残余压痕深度,减少在纳动循环过程中的能量耗散;增大载荷或增加循环次数均可加剧材料的纳动损伤;40Cr基体的纳动损伤表现为压痕边缘的塑性堆积;而CrNx薄膜的纳动损伤由表面的径向和环向拉应力所引起,表现为环向裂纹和径向裂纹的萌生与扩展.
Radial nanofretting behavior of 40Cr and chromium nitride film （ CrNx） were studied by a nanoindenter with a spherical probe of 20μm in radius. The experiments focused on the dependence of the nanofretting damage of samples on the peak indentation forces and the number of nanofretting cycles. The increase in both indentation force and the number of nanofretting cycles induced the radial nanofretting damage of samples. Due to the higher hardness and elastic modulus of the coated CrNx film, the anti-pressure ability of 40Cr substrate was effectively improved. Under the same condition, the CrN film exhibited larger contact stiffness, smaller residual indentation depth and less energy dissipation than 40Cr substrate. The radial nanofrening damage of 40Cr was explained in terms of the pileup of the plastic deformation around indents. However, the radial nanofretting damage of CrNx film was characterized as the initiation and propagation of the ring and radial cracks, which were raised from the radial and hoop tensile stress on the interface of CrN film and substrate.
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2008年第4期316-321,共6页
Tribology
基金
国家自然科学基金资助项目(50625515
50521503)
博士点基金资助项目(20050613023)
