MECHANICAL PROPERTIES OF TITANIUM OXIDE THIN FILMS DEPOSITED BY MAGNETIC FIELD SPUTTERING AT DIFFERENT PARAMETERS

Thin films produced with various coating techniques have a wide range of applications. These techniques are used in protective coatings, solar films, cutting tools, foldable electronic devices, optical and optoelectronic sectors, sensor technologies, medical devices andthe aerospace industry. Different thin film production methods have been developed to address these various applications. Thin films provide protection to the surfaces and materialsthey cover against external effects such as friction, corrosion and temperature.Hardness is a measure of a material's resistance to plastic deformation such as abrasion,scratching, puncture and cutting. The hardness value of a material gives an idea about its mechanical properties such as ductility, strength and toughness. Therefore, hardness measurements are an important mechanical control.Titanium oxide (TiO2) is widely used as a coating material due to its excellent mechanical andwear-resistant properties. Among the PVD (Physical Vapor Deposition) methods, the magnetron sputtering technique is preferred for depositing oxide thin films. This technique allowsthe use of composite targets and the deposition of oxide thin films from high purity solid targets in a reactive environment. Reactive mode thin film deposition allows researchers to control the oxygen and metallic component ratios of the thin film. However, due to the insulatingproperties of oxide films, the deposition process may be adversely affected, if appropriate parameters are not selected. In this study, TiO2 thin films were deposited on AISI 4150 (50CrMo4)and AISI 4150 N (nitridated) substrates using different parameters. The effects of both substrate and deposition process parameters on the hardness of the coatings were investigated.The deposition processes were also performed using various combinations of parameters such&nbsp;as OES (optical emission spectroscopy), current, and bias voltage. There are several methodsto measure hardness. Among these, the nanoindentation method was used because it allowsthe determination of the hardness of thin film coatings without the need for imaging. Hardnesstests were performed using a CSEM nanoindentation tester. The hardness values of sampleswith different oxide-based coated substrates were analyzed by comparing the experimentalresults with the thin film production parameters. Measurements were taken from five different points of each sample and the average values were calculated. After measuring the hardness and elastic modulus of AISI 4150 and AISI 4150 N samples coated with TiO2, the resultswere compared according to OES, current and bias voltage. The analysis of the obtained graphsrevealed varying results depending on the substrate material. The TiO2 coated AISI 4150 Nsample showed higher hardness and elastic modulus values than 4150 steel. The highest valuesfor the coating were obtained at 150 OES, 9 Ampere and 100 Bias voltage. According to theseresults, in applications where hardness is a critical factor in the selection of thin film coatedmaterials, OES, current and bias voltage values are important parameters to be considered.<br>