Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Abstract

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processed by the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ball milling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states such as a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine the structural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated with the Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures; the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coating process is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). The TiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understanding the evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hard coating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that corresponds to an increase in the silicon nitride contents.