Low-cycle fatigue behavior of in situ TiB2/Cu composite prepared by reactive hot pressing

Abstract

Copper-based composite reinforced with in situ TiB2 particulates was prepared through reactive hot pressing of Ti, B and Cu powders. The formation of in situ TiB2 particulates was verified by the X-ray diffraction technique. Tensile test showed that fine TiB2 particulates were very effective to increase the tensile and yield strengths of copper at the expense of tensile ductility. Strain-controlled low-cycle fatigue measurements demonstrated that the in situ TiB2/Cu composite exhibited essentially stable cyclic stress response behavior under small total strain amplitudes of 0.1–0.3%. However, this composite exhibited slight cyclic hardening under strain amplitude of 0.4%. Such cyclic hardening was more pronounced at a total strain amplitude to 0.6% due to the formation of dislocation cells and networks. Finally, the fatigue life data of the in situ TiB2/Cu composite can be described by the Coffin–Manson equation.