EXPLORING THE IMPACT OF RESIDUAL COMPRESSIVE STRESS ON TENSILE PROPERTIES OF MULTILAYER COATINGS BASED ON INVERSE ANALYSIS METHOD

Coatings have extensively been used to the surfaces of critical components to enhance their service life, and the research on mechanical properties of coatings is essential for advancing this technology. TiAlN/Ti and TiN/Ti multilayer coatings were prepared on aluminum matrix composite surfaces by using the vacuum ion beam sputtering technique. The microstructure, phase composition， and mechanical properties of the coatings were characterized and analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and nanoindentor. The dimensionless function correlation between mechanical properties of material with multilayer coatings and the loading/unloading parameters of nanoindentation was derived based on dimension analysis theory, and its explicit expression was determined in conjunction with the finite element simulation method. By establishing a nanoindentation simulation model for the multilayer coating, the impact of residual compressive stress on the tensile properties of the multilayer coating was analyzed. The results indicate that residual compressive stress can enhance the yield strength of the multilayer coatings. The residual compressive stress of TiN/Ti multilayer coating is -564 MPa, increasing the yield strength by 31.25%. Similarly, the residual compressive stress of TiAlN/Ti multilayer coating is -871 MPa, resulting in a 50% increase in yield strength. An important theoretical and test basis is proposed for quantitative analysis of the factors influencing the mechanical properties of coatings.