【摘要】 采用非自耗真空电弧熔炼法制备了（TiB+Y₂O₃）/近α钛复合材料铸锭并对其在β相区和近β相区进行了等温多向锻造（IMDF），研究了不同温度下多向锻造复合材料的组织演变和强化机制。结果表明：多向锻后复合材料基体组织呈网篮状，微米级TiB长纤维由于应力集中而断裂并沿着最后一次的变形方向定向排列，亚微米级Y₂O₃颗粒的尺寸和分布在变形前后几乎未改变。近β相区变形的组织晶粒更细小，且存在少量等轴α相，这些α等轴晶来源于粗大初生α板条的动态球化。锻造变形后复合材料的强塑性显著提升，其中在1 010℃多向锻造的复合材料室温抗拉强度和延伸率为1 178.5 MPa和11.2%,650℃抗拉强度和延伸率为709.3 MPa和25.7%。多向锻造复合材料优异的力学性能主要归因于基体晶粒细化及增强相产生的热失配强化和Orowan强化。然而，变形时TiB晶须的折断在一定程度上削弱了其承载强化效果。更多还原

【Abstract】 Non-self-consuming vacuum arc melting method was used to prepare（TiB+Y₂O₃）/near-α titanium composite ingot and isothermal multidirectional forging（IMDF） was performed in the β-phase and near β-phase regions to investigate the microstructure evolution and strengthening mechanisms of the multidirectional forged composites at different temperatures. The results show that the matrix of the composite is a basketweave structure after multidirectional forging, the microscale TiB long fibers are fractured due to stress concentration and aligned along the direction of the last deformation, and the size and distribution of sub-microscale Y₂O₃ particles are almost unchanged before and after deformation. The microstructure deformed in the near β-phase region has finer grains and a small amount of equiaxed α phases, which come from the dynamic spheroidization of coarse primary α laths. The strength and plasticity of the composites are significantly increased after forging deformation, where the ultimate tensile strength and elongation of the composites deformed at 1 010 ℃ are 1 178.5 MPa and 11.2% at room temperature, and 709.3 MPa and 25.7% at 650 ℃. The excellent mechanical properties of multidirectional forging composites are mainly attributed to the grain refinement of the matrix and the thermal mismatch strengthening and Orowan strengthening generated by the reinforcements. However, the fracture of TiB whiskers during deformation weakens the load-bearing strengthening effect to a certain extent.更多还原