Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 22, 2018 - December 24, 2018
Titanium boride (TiB) whisker reinforced Titanium (Ti) alloy matrix (TiTiB) composites have attracted attention as the aerospace materials with their high specific mechanical properties for long time. Furthermore, TiB whiskers are chemically stable in the Ti alloys and it seems that the slight difference in the thermal expansion coefficient between TiB and Ti allows a remaining thermal stress inside the TiB whiskers to be dispersed within TiTiB composite. Therefore, it is likely that TiB can be a prime candidate for the reinforcement of TMCs. However, it has been reported that the TiB whiskers addition causes the embrittlement of Ti alloys, while TiTiB composites have outstanding tensile strengths in previous studies. We observed that TiB whiskers were firstly fractured in Ti-6Al-4V alloy matrix under tensile load, and it was seemed this fracture caused the embrittlement of Ti alloys. In this study, using Ti particles with a diameter of 100 ~ 150 μm, TiB whiskers were dispersed around Ti particles and formed TiB network inside Ti matrix. It is likely that this microstructure allows to improve both of their tensile strength and fracture elongation. We evaluated the tensile properties of TiTiB composite with TiB network inside Ti matrix.
