Testing Method Optimization And Experimental Study On Interfacial Combined Function Of Laser Scratch

Coating technology which can largely improve the properties of materials with a coating and make the best use of the substrate and the coating material is the leading edge in the scientific research nowadays. The detection technology of it is the bottleneck and focus in the development of coating technology. Laser scratch use the long-pulsed infrared laser direct quasi-static loading on the coating film surface, using the quasi-static thermal coupling mechanism of long-pulsed infrared laser pulse, the scratches formed gradually increase the depth of the coating surface, using laser beam parameters in combination with test parameters and the coating - substrate material physical parameters when interface damaged to characterize the coating - substrate interface. However, the existing measurement principle of laser scratch testing and calculation in some issues need further study.First, research and application of characterization of interfacial bonding strength by laser scratch test method, discrete scratch for the status quo of laser detection technology is presented. Its core idea is: The laser power density range of the coating's failure is found quickly by use of optimization, in the context of the coating through use of pulsed laser to single-point single-load, forming a gradual increase in the depth of the point-like discrete scratches to a shorter planning trace length of the coating failure can be determined the critical point. Pulsed laser single point load will affect the determination of the laser energy parameters and the coating - substrate material parameters on the system, making the test results analysis, computation and processing simple.Secondly, carry out an optimization Method of Route Testing and Experimental Research on Pulse Laser Scratching Technique, proposed method of coating failure to obtain the critical point of failure determine the threshold, resulting in improved scratch efficiency and reduce the destruction of the coating achieved scratch path optimization. Analysis and comparison the experimental results show that the critical point of coating failure by discriminant method is accurate and reliable, laser scratch path optimization is feasible.Thirdly, A new detecting method of pulse laser discrete scratching is presented to estimate the bond strength of film-substrate interface and a device is designed to achieve the automation of discrete scratch. Gradually approximation in order to determine the fact coating failure threshold and the design achieve intelligent discrete scratches.Finally, the finite element tool to create a finite element model to study the coating - substrate system variation of the stress field by the protective coating of stainless steel with Ni Gaussian mode laser single point of loading, and experiment with the scratch test compared the situation of stress. Laser scratch experimental Stainless steel protective Ni coating by laser scratch testing equipment that was successed in research and development. Single-pulse laser scratch path optimization Duigai hard coatings for testing, access to the actual failure threshold and verify that the method of hard coatings feasibility and reliability.