2019 Volume 58 Issue 1 Pages 82-85
To improve the mechanical properties and to optimize the manufacturing process of Cu–Ti alloy, we investigated the effect on the homogenization heat treatment and the effect on the cooling rate in solidification of Cu–3 mass%Ti alloy. In the as–cast sample, the lattice parameter increased and electrical conductivity decreased with increasing cooling rate, because of the increase in the Ti solubility. In addition, the secondary dendrite arm spacing and size of particle precipitated in inter–dendritic decreased with the increasing cooling rate in solidification. The deviation in the mechanical properties change with the cooling rate shown in the as–cast sample decreased after the homogenization heat treatment. In addition, even in the process without homogenization heat treatment, the deviation in the properties change with the cooling rate decreased after the solid solution heat treatment. The process of which cold working was applied prior to the solution heat treatment showed the improvement of mechanical properties compared to other processes. Microstructures of the alloy revealed that there was no difference in the precipitates shape according to the type of the process. However, the volume fraction of grain boundaries increased due to the grain refinement in the mechanical properties improved process. Therefore, the volume fraction of precipitates highest at the improved process and the precipitates were finely distributed.
