通孔式钛合金层强韧化Ti2AlC/TiAl基叠层复合板材

以通孔式结构TC4钛合金箔为增韧层,以TiC-Ti-Al混合粉末为反应体系,采用放电等离子烧结技术(SPS)制备TC4/Ti2AlC-TiAl基叠层结构复合板材。借助XRD、SEM等分析相组成和组织结构,并测量室温弯曲强度和断裂韧性。结果表明,叠层结构复合板材的力学性能呈各向异性;当Ti2AlC含量(质量分数)为15%时,断裂韧性在加载方向垂直于叠层方向时达到最大值18.81 MPa·m1/2,远高于无Ti2AlC的复合板材的断裂韧性。通孔叠层结构设计以及复合化手段构建了复杂的裂纹扩展路径,且钛合金韧化层可以吸收断裂能,对改善韧性具有重要作用,为金属复合板材研究提供了一种全新的设计思路。

Ti2AlC/TiAl-based laminated composite sheets strengthened by titanium alloy layers with through-holes

The TC4/Ti2AlC-TiAl based laminated composite sheets were prepared by the discharge plasma sintering technique(SPS),using TiC-Ti-Al system mixed powders as the reaction system and TC4 titanium alloy sheets with through-holes as the toughening layers.The phase composition and microstructure were analyzed by XRD and SEM,and the room temperature flexural strength and fracture toughness were also measured.The results indicate that the mechanical properties of the laminated composite sheets have anisotropy.When the content(mass fraction)of Ti2AlC is 15%,the fracture toughness reaches a maximum value of 18.81 MPa·m1/2 and it is much higher than that of the composite sheet without Ti2AlC,while the loading direction is perpendicular to the laminated structure.The through-hole laminated structure design and particle composite technology construct the complex crack propagation paths.Moreover,the titanium alloy toughening layers can absorb fracture energy,which play an important role in improving the toughness.Such design provides a new design idea for metal-based composite sheets.