A new approach to study of TiB2-TiN-SiC based tribological coatings with solid lubrication

Abstract

An in-situ TiB2-TiN-SiC composite coating is deposited over steel substrate through laser treatment of a preplaced mixture of TiO2, SiO2, hBN and graphite powders. Coating’s characteristics change significantly on individual additions of hBN and SiC to other constituents. This study focuses on checking the benefits of simultaneous addition of hBN and SiC on coating’s properties using K-nearest neighbor (K-NN) methodology. Here, specific amounts of both hBN and SiC are added simultaneously in the precursor mixture (as found suitable through K-NN methodology) to study coating’s characteristics in a situation where advantages of hBN as solid lubricant can be obtained without compromising the various mechanical properties. Characteristics of the coating developed with that composition of precursor mixture ensuring simultaneous addition of hBN and SiC is thoroughly studied through several microstructural, tribological and mechanical characterizations. On evaluation of tribological properties of the coating at varying loads, presence of both hBN and SiC shows interesting results. A coating with stoichiometric proportion of precursor mixture is also deposited and characterized for comparison. © 2021, Indian Academy of Sciences.