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

• Ultrafine equiaxed grained composites were formed by spark plasma sintering.
• The composites exhibit ultimate strength of 2585 MPa and plasticity of 34.2%.
• The ultrahigh strength is due to dislocation pile-up induced by precipitated phase.
• The large plasticity is ascribed to slip band propagation in the matrix.

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.

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