Ultrafine grained Ti-based composites with ultrahigh strength and ductility achieved by equiaxing microstructure

摘要

Ultrafine grained Ti-based composites with equiaxed microstructure were fabricated by sintering and crystallizing from glassy powder precursors. The optimized composites exhibit ultimate strength of 2585 MPa and plasticity of exceeding 30%, occupying an unprecedented regime in the strength and ductility space of advanced titanium alloys. Dislocation pile-ups induced by precipitated phases and slip band propagation in the (β-Ti matrix are the main reasons for the ultrahigh strength and plasticity respectively. The results provide an innovative route for fabricating titanium alloys with higher mechanical properties.