Abstract:In order to overcome the poor mechanical properties of HA and the low bioactivity of Ti, HA/Ti composites with various compositions were prepared by mechanical milling. The effects of milling condition and the composition on the microstructure, the density and the hardness of the composites were studied. The results show that during the ball milling process, Ti particles are refined and the homogeneity of the HA/Ti mixtures is improved; HA will partially decompose due to the existence of Ti and high sintering temperature. The microstructure of HA/Ti composites is highly dependent on the milling condition and the composition. In the microstructure, Ti phase connects to be a continuous network, and HA/Ti mixtures disperse in the network. The longer the milling time, the finer the network will be. The density of HA/Ti composites decreases with the content of HA increasing and the milling time prolonging, because HA deteriorates the sinterability of Ti.The hardness of HA/Ti composites increases firstly with the content of HA increasing, and then drops when the content of HA exceeds 30%. Addition of HA will strengthen the HA/Ti composite but will decrease the density of the composite, which accounts for the effect of HA on the hardness of the composites.

Key words:  HA/Ti composite; mechanical milling; microstructure