添加Mo2TiC2的新型两相Mo-Si-B合金的制备与韧化机制研究

钼硅硼合金在1200℃以上高温下具有优异的抗氧化和抗蠕变等综合性能。但目前该合金室温韧性与高温强度及抗氧化性能之间存在显著的负相关关系制约了该合金在高温合金领域的应用推广，本项目针对此矛盾，以提高合金的室温韧性而不降低高温强度及抗氧化性能为目标，拟研究开发一种仅由Mo与Mo5SiB2两相组成的新型钼硅硼合金材料及其粉末冶金制备技术，通过微观组织设计与调控，澄清两相各自及相互耦合对合金性能的影响规律与微观作用机制；通过添加具有MXene相结构且能显著韧化钼合金的的Mo2TiC2颗粒，系统研究该颗粒添加所引起的钼硅硼合金微观组织细化、断裂行为、高温氧化行为及其对性能的影响规律。阐明所研究合金微观结构参数及其耦合作用所产生的韧化和抗氧化机理，并建立相应的微观力学模型，获得钼硅硼合金的成分、微观组织、力学性能及抗氧化性能之间的关联。研究结果可为开发具有理想综合性能的高温合金提供实验数据和理论基础。

There is a significant negative correlation between the room temperature toughness and the high temperature strength and oxidation resistance of the Mo-Si-B alloy, although the Mo-Si-B alloy has excellent comprehensive properties, oxidation resistance and creep resistance properties at high temperature above 1200 ℃, which affects the applications of the alloy in the field of high temperature. In order to addresses this contradiction and improve the room temperature toughness of the Mo-Si-B alloy without reducing the high temperature strength, this project aims to develop a new two-phase Mo-Si-B alloy which composed of Mo and Mo5SiB2 only. The alloy with different microstructure will be designed and prepared to clarify the influence and mechanism of two phases and their mutual coupling on the properties. By adding MXene phase structure Mo2TiC2 particles, which can significantly toughen molybdenum alloys, the microstructure refinement, fracture behavior, high-temperature oxidation behavior and its influence on properties will be systematically studied. The microstructure parameters of the alloys studied and their toughening and oxidation resistance mechanisms will be clarified, and corresponding mechanical models will be established, and the relationship among the composition, microstructure, mechanical properties and oxidation resistance of the alloy will be obtained. The research results can provide experimental data and theoretical basis for the development of high temperature alloys with high room temperature toughness and good high temperature strength and oxidation resistance.