Microstructure and Mechanical Properties of In-situ Synthesized TiB+TiC Reinforced Ti-Fe Matrix Composites

Ti-Fe matrix composites were prepared by cold isostatic pressing（CIP）+ vacuum sintering using Ti,Fe and B₄C powders as the raw materials.The effects of the Fe content and volume fraction of the reinforcements on the microstructure and mechanical properties of the composite were discussed.The results show that the relative density of the composites reduces with increase of the Fe content and volume fraction of reinforcements at 1 150 ℃ to 1 250 ℃ of sintering temperature.The α lamellar structure is refined with increase in the Fe concentration.TiB whiskers and TiC particles can be in-situ synthesized as the reinforced phases with the addition of B₄C powder,and the microstructure of the matrix changes from lamellar to equiaxed structure.The mechanical properties of the composite increase with increase of the Fe content and the volume fraction of reinforcements.The composite of Ti-15%Fe-10%（TiB+TiC）having a micro-hardness of 334 HV and compression strength of 2 040 MPa can be obtained at 1 150 ℃ of sintering temperature.