Numerical investigation on the bond strength of a SiCN-based multi-layer coating system

SiCN film is promising coating material in wear-resistance and high strength applications, the interfacial strength between SiCN and substrate is the major issue needs to be concerned. Designing SiCN-based multi-layer coating system is a proper solution. To investigate the mechanical performance of the system, in this work, a nano-indentation model constituted by nano-indenter and SiCN-based multi-layer coating is established by finite element approach. The interfacial properties are investigated by comparing the simulation load - depth (P-h) curves with experimental results. The simulation results indicate that the sharply changed shear stress at interface will significantly decreased by adding the interlayer, and the maximum shear stress decreases with the increase of interlayer thickness. Moreover, the location of the maximum tensile stress for SiCN surface is not at the axis of indenter, which is related to the pile up phenomenon at coating surface. The proposed approach can be used to evaluate and design the mechanical performance of SiCN-based multi-layer system.