激光法定量测试界面动态和准静态结合强度基础研究

The adhesive strength of interfaces (tensile strength) is the issue in the field of interface research. However, how to determine the tensile strength of interfaces directly and quantitatively is still a difficult problem for scientists in the world. Recently, the laser spallation technology has attracted many researchers because of its potential application on the measurement of the adhesive strength of the interfaces. This article investigates the spall process on the interfaces induced by lasers and the quantitative determination technique...First, after reviewing on the progress of measurement technique of the adhesive strength on the interfaces, a key issue of quantitatively determining the adhesive strength on the interfaces is proposed according to the conception and detection theory of adhesive strength on the interfaces. The issue is how to realize single and unite tensile fracture on the interfaces while maximally suppressing plastic deformation on neighboring area and avoiding the extension of crack. The ideal detection method is separating the interfaces by the micro-nucleation mechanism.The shortcoming and weakness with existing methods, especially with laser spallation methods are demonstrated.Next, the article discusses the principle of the coating spallation on the interfaces induced by pulsed lasers, and proposes the principle of the quantitative determination of adhesive strength on the interfaces. In the dynamic spall process of interfaces, the stress history on the free surface of coatings reflects the real loading history on coatings with unique, certain and detectable characteristics. Basing on the determination of the spallation on the interfaces and the spall information, the detection model of the interfaces between substrate and coating is built and optimized; the optimization technique of the loading stress inducing the spallation of the interfaces is also quantified to educe the optimization relationship between the pulse step of the stress wave and the time scale of the coating thickness; the design on optimizing pulsed stress wave and coating samples are obtained.Then, the real-time and quantitative determination technology of spallation is presented, through which the quantitative determination of the adhesive strength, strain rate and damage scale of the interfaces in only one experiment of laser spallation can be realized. Moreover, the finite element analysis is used to investigate the spall process on the interfaces induced by the laser impaction, and the methods to determine the threshold of stress on the interfaces are proposed, the efficiency of which have been validated by comparing with experiment data.Finally, the measurement equipments of impaction system with high energy and short pulse width lasers, and the noncontact stress wave reception monitories system, based on the Fabry-Periot interferometer technology are developed. These facilities fill a vacancy in the field in our country. Generally speaking, we have achieved creative advancement as follows:.We develop and integrate the measurement equipment of impaction system with high energy and short pulse width lasers, and the detection system to receive and non-contactly detect the stress wave based on the Fabry-Periot interferometer technology. With the characteristics of non-contraction, high sensitivity and high convergence of optical energy, our systems can efficiently detect acoustic longitudinal wave, acoustic transversal wave and acoustic surface wave in the transmission model and reflection mode. Precise 5-Axis Cooperation NC worktable can realize the accurate localization of laser beams and samples and repeat experimentation.2.Based on multiply reflection and transmission inside coatings, the mathematic model of quantitative determination of intrinsic adhesive strength on interfaces is built; the mathematic equation for calculating the adhesive strength on the interfaces and corresponding strain rate on the situation of spallation are concluded. The mechanical behaviors of spall process o

应用激光对薄膜进行动态和准静态加载全面测定薄膜动、静态结合强度。测量激光冲击所产生的应力波，运用时频分析法实时判定薄膜层裂各阶段。对激光层裂过程数值模拟和解析分析，实现单次冲击一次定量测定薄膜界面拉伸强度。创立一种更科学更正确的薄膜界面拉伸强度测量新理论和新技术，这对界面科学研究和界面质量控制有重要意义和广阔应用前景。