The effect of heat treatment on the tensile strength and ductility of pure titanium grade 2

Abstract

The commercially pure titanium (CP) and titanium alloy are widely used in medical, aerospace and automotive industries due to their attractive mechanical properties especially because of its strength-to-weight ratio that is the highest among all known metal. A thorough understanding of the mechanical properties of titanium is very important so that an optimize machining parameters can be selected. Pure titanium has a higher level of corrosion resistance compared to titanium alloy due to the presence of an oxide layer on its surface. In this paper, heat treatment especially the annealing process was used prior to machining in order to study on the variation of its tensile strength and ductility at two different annealing conditions. The three conditions that were used in this experiment are untreated (T1), heat-treated at 700°C for 1 hour (T2) and 900°C for 1 hour (T3). In this work, a higher level of oxidation was observed for T3 compared to T2 due to the exposure to a temperature that is above the beta transus temperature that triggered the formation of acicular martensite. It was also observed that there was a decrease in the tensile strength when treated at T2 and a recovery of the strength was noticed at T3. The ductility properties were more significant at T2.