MECHANICAL-PROPERTIES OF PARTICULATE REINFORCED TITANIUM-BASED METAL MATRIX COMPOSITES PRODUCED BY THE BLENDED ELEMENTAL P/M ROUTE

The titanium-based metal matrix composites (MMC) reinforced with relatively large-sized ceramic particulates have been produced by the blended elemental (BE) P/M route. The extra low chlorine titanium powder, Al3Ti master alloy powder, and FeB and Cr3C2 ceramic powders were used as starting materials. The dispersion of either TiB or TiC particulate reinforcements in the matrix were therefore made in situ during the sintering process. The distribution of particulate reinforcements in the matrix was reasonably random. Tensile tests were done at temperatures up to 923 K. It has been found that the tensile strength of these composites are superior to those of the unreinforced matrix alloys in the whole temperature ranged examined. The elastic modulus was also increased by the presense of these ceramic reinforcements. No ductility was found for both composites at room temperature, but some ductility was observed at temperatures above 623 K. These observations were interpreted in terms of the failure mechanisms observed using scanning electron microscopy.