High temperature tensile properties of in situ TiBw/Ti6Al4V composites with a novel network reinforcement architecture

TiB whisker reinforced Ti6Al4V (TiBw/Ti64) composites with a novel network reinforcement architecture have emerged due to their superior combination of superior room temperature tensile properties. In the present study, their superior high temperature tensile properties and special strengthening mechanisms were further investigated. At 500°C, the tensile strength of the as-sintered 5. vol.%, 8.5. vol.% and 12. vol.% TiBw/Ti64 composites increased by 36.9%, 40.5% and 44.8% compared with that of the monolithic Ti64 alloy. Moreover, the tensile elongations are close to 10% at 500°C and 20% at 700°C. The maximum service temperature of the TiBw/Ti64 composites can be increased to 600°C while retaining the strength of the monolithic Ti64 alloy the alloy at 400°C. This is attributed to the network boundary strengthening mechanism as elucidated by the microstructure-property-fractographic analysis.