激光薄膜层裂技术的理论建模及相关诊析技术

Theoretic Modelling and Correlation Detection of Pulsed Laser Film Spallation Technology

以定量检测Al2 O3薄膜 /steel体系薄膜界面动态结合强度为目的 ,应用改进激光层裂装置 ,利用高功率脉冲激光冲击薄膜表面能量吸收层产生向基体内部传播的高幅应力波 在自由表面应用激光探针对心记录到达该面的应力波引起的振动位移 通过应力波分析、数据处理和数值模拟 ,建立了应力波传播与衰减模型 经过应力波相关技术表征 ,建立了关于界面损伤发展的 3个阶段 :初始脱粘、裂纹扩展、薄膜剥离的新的层裂判别准则 同时 ,根据应力波的到达时间和衰减方式 。

With the aim of measuring quantitatively the dynamic adhesive strength of Al 2O 3film/Fe, we use a modified laser spallation setup, and let high power laser pulse shock the energy absorbing thin coats, then cause a pressure pulse propagates to matrix. At the free surface, a laser probe is used to record the epicentral surface displacement history caused by stress wave which propagates to the free surface. Through the analysis of stress wave, data processing and a computer simulation, we propose a novel model of the attenuation and the dispersion of the stress wave. After characterizing, we obtain new spallation criteria corresponding to progressive damages at the film matrix interface, i.e. interface delamination, film spallation and film expulsion, respectively. At the same time, according to the arrival time and attenuation pattern of the stress wave, we also propose a new computer algorithm for estimating the source fracture dimension.