Breakdown of TiN coating on HSS steel substrates through Rockwell indentation and inverse modelling of substrate behaviour

摘要

This paper presents the identification of multi-linear stress strain law for High Speed steel (HSS) which enables the determination of critical stress and strain components which lead to the failure of Titanium Nitride (TiN) coating, coated on to it. The procedure of identification relies on an inverse method, where Rockwell indentation experimental profiles are matched with the profiles obtained by Finite Element (FE) simulation of the indentation process using LS-DYNA non-linear FE-code and XIMCOR inverse modeling/optimization program. Radial cracks observed in the coating due to indentation, tends to arrest at characteristic length (L_c). The stress/strain condition in the coating at these lengths, which are the critical components for the breakage of the coating, is calculated explicitly, compared to previous works and intended to be used as a failure criterion in our further works.