重载条件下钢基体表面涂层裂纹及分层失效-中国表面工程.PDF

第 29 卷 第 6 期 中 国 表 面 工 程 Vol. 29 No. 6 2016 年 12 月 CHINA SURFACE ENGINEERING December 2016 doi: 10.11933/j.issn.1007−9289.2016.06.017 重载条件下钢基体表面涂层裂纹及分层失效* 邹梦杰，石万凯，肖洋轶，杨槐峰 (重庆大学 机械传动国家重点实验室，重庆 400044) 摘 要: 用有限元法分析了Hertz接触应力下钢基体表面涂层裂纹和分层失效状况，采用无预制裂纹状况下的扩展有 限元(XFEM)技术和内聚力(Cohesive)模型研究了涂层的裂纹扩展和分层失效过程。分析表明：涂层的裂纹萌生于涂层 表面，并向内部扩展；涂层弹性模量越大越易产生裂纹，且裂纹扩展越深。涂层的分层失效主要是由涂层-基体界面 切应力造成；由于畸变应力的存在，较薄涂层(如物理气相沉积涂层) ，涂层越厚越易产生分层；较厚涂层(如等离子喷 涂涂层) ，涂层越薄越易产生分层。在另一方面，涂层的裂纹和分层会相互影响，分层会使涂层更易产生裂纹，使裂 纹扩展越深，影响裂纹扩展速度；涂层裂纹会使涂层更易分层，使分层区域在远离接触区域方向上不断扩展。对比 分析表明，研究结果与前人的理论及实验结果吻合较好，为今后进行涂层失效数值模拟提供了依据。 关键词: 裂纹；分层；扩展有限元；内聚力模型 中图分类号: TG174.442; TG115.57 文献标志码: A 文章编号: 1007−9289(2016)06–0123–06 Cracking and Interfacial Delamination in Coated Steel Under Heavy Load Conditions ZOU Meng-jie, SHI Wan-kai, XIAO Yang-yi, YANG Huai-feng (The State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing 400044) Abstract: The cracking and interfacial delamination in coated steel under Hertz contact were investigated based on finite element method. The evolutions of the crack propagation and interfacial delamination were evaluated by using extended finite element method (XFEM) and cohesive zone model. The results show that the coating crack initiates from the coating surface, and propagates to the interface. The larger the coating elastic modulus, the more likelihoods of the cracking and the deeper crack. The delamination is mainly caused by the interfacial shear stress. In the case of the thin coating (e.g., physical vapor deposition coatings), it tends to cause i