Abstract
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Multi-directional forging is a kind of severe plastic deformation process to obtain ultrafine-grained material in large size bulk, which can significantly improve the microstructure and mechanical properties of materials, and especially has a wide application prospect in plastic processing of difficult-to-deformation materials. The latest advances on multi-directional forging process of titanium alloys, TiAl-based alloys, Ti2AlNb based alloys and titanium based composites were summarized, including the principle and characteristics of multi-directional forging, microstructure evolution in multi-directional forging of titanium alloy, TiAl based alloys, Ti2AlNb based alloys and titanium based composites, mechanical properties enhancement and low temperature superplasticity of alloy after forging, and formation process of ultrafine-grained structure. Special attention was paid to their microstructure, hot processing and low temperature superplasticity deformation. The main problems existing in multi-directional forging of titanium-based alloys were analyzed, and the future research directions were prospected.