The influence of thermal oxidation parameters on the growth of oxide layers on titanium

The research presented in this paper concentrates on determining the influence of temperature and time parameters on the process of growth, the thickness, mechanical properties and roughness of oxide layers obtained on titanium Grade 2. It has been found that the temperature has a more important influence on the process of forming oxide layers on titanium than time. Increasing the oxidation temperature from 600 to 700 °C caused an increase in the specimens' weight gain by as much as five times. The thickness of the formed oxide scale varied, depending on the adopted temperature/time parameters. Layers obtained at 600 °C had a thickness ranging from 0.40 ± 0.04 to 1.37 ± 0.08 μm for oxidation time of 6 and 72 h, respectively. Layers with a much higher thickness (from 1.53 ± 0.24 to 6.01 ± 0.22 μm) were obtained during oxidation at a temperature of 700 °C at a time of 6–72 h. Hardness of the obtained oxide layers grew with an increasing temperature and extended time of oxidation. It has been found that hardness decreases as the distance from the surface increases, but the hardness below the oxide layer was still higher than in the case of an alloy not subjected to oxidation.