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TiB was planted into the matrix titanium alloy through the rapid solidification process, and the new ultrafine network reinforced titanium matrix composites (TMCs) powder was formed. Based on the laser additive manufacturing technology, a new titanium matrix composite with alternate distribution of equiaxed network and columnar network structure were creatively fabricated, the formation mechanism of the network structure was systematically discussed, and the mechanical properties of the super-solidified TMCs by additive manufacturing were tested. The results indicate that the network structure (about 9 μm) of the additively manufactured TiB/Ti composites is mainly composed of in-situ nano-TiB whiskers, presenting two crystal structures of B27 and Bf. The direct introduction of B element is easy to form constitutional supercooling at the solidification interface. The equiaxed α phases are obtained by promoting the alternating formation of equiaxed/columnar network structure and refining the grain size. In addition, the formed nano-TiB network structure, not only inhibits the crack deflection and passivate cracks, but also confines the large number of slip lines inside the TiB network structure via in-situ observation, inducing high-density dislocations at the grain boundaries, which limites its plastic deformation, and greatly improves the strength of the composites. The additively manufactured TiB/Ti composites increases the tensile strength by 42%, and maintains the elongation of about 10%.

Under the high-energy particle impingement and cascade effect, different types of radiation damage defects occur in metals. The aggregation and evolution of radiation damage defects can lead to the destruction of the internal structural stability and the deterioration of their properties of metals. Titanium alloy is a promising radiation resistant alloy due to its advantages of light weight, high strength, high temperature resistance and low radiation activity. Aiming at the improvement of the radiation damage resistance, this work summarizes the research progress on the radiation damage defects, the microstructural features and mechanical properties of titanium alloys. In addition, the formation and evolution of radiation damage defects and the influence mechanism of radiation dose, temperature and element species on defect migration and aggregation are analyzed. The microstructure evolution of titanium alloys induced by irradiation and the radiation damage effects such as radiation hardening, radiation embrittlement and radiation creep are discussed. The radiation damage resistance properties of titanium alloys are summarized and evaluated. The existing researches are lack effective methods to inhibit the radiation damage. Finally, the effective strategies to improve the radiation resistance of titanium alloys through composition regulation and interface microstructure design are prospected.