高斯激光辐照下膜基系统的温度场和应力场的瞬态分析

Study on the temperature and stress field of film-substrate system irradiation by gauss laser

本文根据加载激光的工艺参数以及薄膜、基体的材料特性,建立了薄膜与基体的有限元模型,对高斯激光在加载在薄膜表面后的温度场进行有限元模拟,获得膜基系统中温度随时间的变化关系以及薄膜界面结合处的温升规律。并在此基础上根据薄膜和基体的热膨胀性能,进行薄膜和基体的应力场模拟,获得了膜基系统的应力场随时间的变化关系。模拟结果表明：在激光加载过程中,薄膜和基体中的温度场随着时间增加,由于热传导系数的差异在薄膜和基体之间产生温差。在膜基系统中产生的应力场主要集中在薄膜内部,膜基界面结合处产生的应力较大会导致薄膜的脱粘。模拟结果定性地反映了薄膜和基体中温度和热应力的变化规律,为分析激光划痕法的作用过程提供了一定的理论依据,对研究膜基系统失效进程具有重要意义。

Based on material characters of film and substrate and process parameter of laser, established the infinite element model, and sire-lAte the temperature field of film - substrate system irradiation by gauss laser, obtain the relationship between temperature field and time, and the temperature rise disciplines of interface. And according the thermal dilatability of film and substrate, simulated the stress of film - substrate system, obtain the relationship between stress field and time. The results indicated that ： in the process of laser irradiation, the temperature field of film - substrate system increasing with the times. Because of the difference between the film and substrate, there becomes the difference in temperature. The stress field of film - substrate mainly in the film, and the stress of interface cause the debonding of the film - substrate system. The result qualitatively reflection the disciplines of temperature and thermal stress in the film - substrate system, provided the theory support of laser scratch testing action process. It has the important meaning of ＇study the process of film- substrate invalidating.