Optimisation of TiN thin film synthesis by a novel combined laser/sol-gel processing technique

The authors recently reported a novel laser-based method for depositing hard TiN thin films. Results of process optimisation are given in this paper. The process chemical thermodynamics, laser interaction with the preplaced slurry that forms the coating and the heat transfer problem during the process are discussed. Surface morphology and microstructure of the deposited coatings and substrate surface layers were examined using optical microscopy, scanning electron microscope, and field emission gun scanning electron microscope which reveals the presence of sub-micron crystalline structure of TiN forming a metal matrix composite interlayer with the substrate below the film which suggest a good metallurgically bonding with the substrate. Chemical composition was determined by energy dispersive X-ray analysis. The phases were identified by X-ray diffraction which confirms the synthesis of TiN film for all the samples. Results of microhardness measurements revealed a hardness value of the order of 2700 HV(0.1).