Nb 相增塑核壳结构 TiAl/Nb 复合材料的制备及组织性能研究

In response to the challenges of the low plasticity at room temperature and difficulty in meeting engineering applications in traditional γ-TiAl alloys, this paper proposed Nb phase plasticized TiAl/Nb composites with core-shell structure, and systematically studied the preparation technology and mechanical properities of the composites. The results show that complete encapsulation of large-sized γ-TiAl atomized powder by fine Nb particle can be achieved after 120 h ball milling at the speed of 200 r/min. Subsequently, a densified core-shell structure with controllable plasticized phase can be obtained after vacuum hot pressing at 1 200 ℃/1 h, under 40 MPa. The prepared TiAl/Nb composites exhibit high strength and good plasticity with the yield strength of 971.5 MPa, compressive strength of 2 337.7 MPa, and fracture strain of 31.7% at room temperature. The high strength and excellent plasticity of the composites are attributed to the ductile β-Nb phase which facilitates coordinated deformation between matrix phase colonies, which thereby enhancing the continuous deformation capacity of the integral bulk materials.