Theoretical-Experimental failure analysis of the c-Al0.66Ti0.33N-M2 steel system using nanoindentation instrumented and finite element analysis

TL;DR

This paper presents a comprehensive theoretical and experimental methodology combining nanoindentation, finite element analysis, and crack pattern analysis to evaluate failure mechanisms and fracture toughness of a c-Al0.66Ti0.33N coating on M2 steel.

Contribution

It introduces an integrated approach using nanoindentation, XFEM, and cohesive zone modeling for failure analysis of hard coatings, including crack pattern prediction and toughness calculation.

Findings

Elastic modulus and hardness of the coating were quantified.

Critical stress values at the interface were determined.

Cracking patterns and failure mechanisms were successfully modeled.

Abstract

A theoretical-experimental methodology for failure analysis of the c-Al0.66Ti0.33N / Interface / M2 steel coating system is proposed here. This c-Al0.66Ti0.33N coating was deposited by the arc-PVD technique. For coating modeling the traction-separation law and the extended finite element method-XFEM were applied, the cohesive zones model was used for interface modeling and the Ramberg-Osgood law for substrate modeling. Experimental values using the instrumented nanoindentation technique, the scratch test and tensile stress test were obtained and introduced into the model. By means of nanoindentation the elastic modulus of coating, the fracture energy release rate and the nano-hardness. Normal and shear stress values of the interface were obtained with the scratch test, at the adhesive and cohesive critical loads. Vickers indentation was used to generate cracking patterns in the c-Al0.66Ti0.33N / Interface / M2 steel coating system. Radial and lateral cracks were generated and analyzed after transversal FIB cuts of the fracture zones. A finite element analysis was carried out to understand the relationship between the load-displacement curve and mechanical failure of in the system, associating the pop-in with nucleation, crack growth and cracking pattern. This works present a theoretical-experimental methodology for failure analysis of hard coatings (monolithic body) allowing to calculate fracture toughness of the coating material and model cracking patterns caused by contact mechanics.