Interface modification of TiAlN coated TiCN-based cermet through plasma nitriding

Abstract

This study aimed to enhance the comprehensive properties of coated TiCN-based cermets through a combination of plasma nitriding (PN) and physical vapor deposition (PVD) of TiAlN. Varied N2/Ar ratio gas mixtures were utilized as the plasma discharge atmosphere. The investigation focused on the structure and characteristics of the coated TiCN-based cermets. Results indicated an increase in surface hardness and nitrogen content on the substrate, along with a refinement in the grain structure of the TiAlN coating following plasma nitriding by adjusting the N2/Ar ratio. The coatings predominantly exhibited the (200) orientation. When the N2/Ar ratio varied, there was a nitrided layer on the substrate surface with a thickness of 1 to 1.5 μm. Moreover, optimal outcomes, including the highest H/E ratio (0.094) for the TiAlN coating, and improved cutting performance of the coated TiCN-based cermet insert, were achieved under the condition of N2:Ar = 1:1.