Improved high cycle fatigue properties of titanium-based particulates composites

摘要

The titanium-based particulates composites are known to exhibit superior physical and mechanical properties compared to the unreinforced alloy. In cases where TiB or TiC is used as the reinforcing particulates, it has been reported that the fatigue fracture or iginates neither from the interior of particulate nor form the particulate/matrix interface, but rather from the matrix. Therefore it is suggested that the high cycle fatigue strength of the composite is strongly dependent on the matrix microstructure. In the present work, the effect of the matrix microstructure on the high cycle fatigue strength was studied for blended elemental P/M Ti-6Al-2Sn-4Zr-2Mo/10TiB and Ti-6Al-1.7Fe-0.1Si/10TiB composites. It was found that the composites with a fine acicular #alpha# -#beta# two-phase microstructure showed an improved high cycle fatigue strength over those conventionally processed composites with colony matrix microstructure.