2018 年 65 巻 5 号 p. 227-232
In our previous study TiB2-reinforced sintered steel with the remarkably high Young’s modulus was obtained for enabling a leaner design of automobile parts. This high Young’s modulus seemed to be due to both the suitable reinforcing particles for steels and the high sintered density provided by hot-work process of sintered billet.
In this study increasing the sintered density was investigated by the process of single-pressing and single-sintering in which near net shape parts were simply and easily manufactured.
In the compacts of steel powders containing TiB2 particles, the liquid phase of Fe-B system formed above 1448 K and enhanced densification of the compacts. In case of 2-15 vol% TiB2 addition, since the effect of this liquid phase on the densification was appreciable, the sintered density above 98% of pore free density was achieved by the vacuum sintering at 1523 K. This high relative density realized the high Young’s modulus comparable to calculated value in each TiB2 contents.