Akademik Veri Yönetim Sistemi
11 th International Conference on Tribology – BALKANTRIB ‘24, Sofija, Bulgaristan, 26 Eylül - 28 Ekim 2024, cilt.1, sa.46, ss.81-82
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 and
the aerospace industry. Different thin film production methods have been developed to address these various applications. Thin films provide protection to the surfaces and materials
they 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 and
wear-resistant properties. Among the PVD (Physical Vapor Deposition) methods, the magnetron sputtering technique is preferred for depositing oxide thin films. This technique allows
the 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 insulating
properties 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 as OES (optical emission spectroscopy), current, and bias voltage. There are several methods
to measure hardness. Among these, the nanoindentation method was used because it allows
the determination of the hardness of thin film coatings without the need for imaging. Hardness
tests were performed using a CSEM nanoindentation tester. The hardness values of samples
with different oxide-based coated substrates were analyzed by comparing the experimental
results 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 results
were compared according to OES, current and bias voltage. The analysis of the obtained graphs
revealed varying results depending on the substrate material. The TiO2 coated AISI 4150 N
sample showed higher hardness and elastic modulus values than 4150 steel. The highest values
for the coating were obtained at 150 OES, 9 Ampere and 100 Bias voltage. According to these
results, in applications where hardness is a critical factor in the selection of thin film coated
materials, OES, current and bias voltage values are important parameters to be considered.