Influence of Al Content on Micro-Properties of TiAlSiN Coatings Deposited by Plasma Enhanced Magnetron Sputtering

Abstract

TiN coating has attracted substantial attention due to its high hardness and good wear resistance. To meet the current more demanding service environment, Al and Si were added to TiN coating to further improve its comprehensive performance in this work. TiAlSiN coatings with different Al content governed by Al target power were prepared on GH169 superalloy by plasma enhanced magnetron sputtering, and the Al content effects on microstructure and mechanical properties of the coatings were explored in detail. The crystal structure, chemical composition, micromorphology and surface roughness of the coatings were analyzed by XRD, SEM, EDS and AFM, respectively. The mechanical properties of the coatings at room temperature including micro-hardness, elastic modulus and bonding strength were evaluated by nano-indentation and nano-scratch, respectively. With the increase of Al target power, Al content in coatings increased, and the preferred orientation of TiN(111) plane was also more and more obvious. At the same time, the surface morphology of the coatings changed from the round cell shape to the hexagonal star shape. The hardness, elastic modulus and adhesion of the coatings increased first and then decreased with the Al content. The TiAlSiN coating with Al content of 19.25% possesses the best comprehensive properties.