Effect of ball milling process on mechanical properties of medical Ti–Mg composites

Ti–15Mg composites were prepared by ball milling, cold pressing, and microwave heating sintering. The effects of ball milling parameters on the properties of the Ti–15Mg mixed powders and the mechanical properties of the sintered composites were studied. The results show that, the average particle size of the mixed powders decreases significantly with the extension of the milling time at the ball milling speed of 200 r·min⁻¹ for 8～10 h, the particle size distribution gradually concentrates in the range of 10～45 μm, and the sphericity of the powders increases. In the process of long-time ball milling, the soft Mg particles are subjected to the strong impact and ground, eventually leading to the soft Mg particles wrapped in the brittle Ti particles. After ball milling for 8 h, there are no obvious oxidations in the mixed powders. The distribution of Ti and Mg powders in the mixed powders are relatively uniform, and the mechanical properties of the composites are relatively excellent, which meets the requirements of medical materials. At low milling speed, the increase of milling speed can not lead to the significant change in the powder’s properties and the sintered composite properties. The optimal ball milling parameters are obtained as the ball milling time of 8 h and the milling speed of 200 r·min⁻¹ with n-hexane as the process control agent.