Microstructural and mechanical comparison of Ti+15%TiCp composites prepared by free sintering, HIP and extrusion

Abstract : Ti +15%TiCp composites were prepared by three different powder metallurgy techniques: free sintering, HIPing and direct powder extrusion. The microstructures and textures were characterized by EBSD while the Ti/TiC reaction, which takes place during heat treatment, was characterized using X-ray diffraction and Rietveld analysis. The mechanical properties were obtained by the mean of tensile tests. TiC particles effectively reinforce the strength of the Ti matrix by at least 40% indicating the Ti/TiC reaction did not deteriorate the mechanical properties. The correlation between the microstructural features and the mechanical properties is discussed and the processes are compared. Direct powder extrusion was shown to be the most suitable process to obtain ductile composites (epsilon = 4.6%).