申请人及其合作者前期研究中开发了一种新型纳米氧化镧颗粒掺杂钼合金，其室温强度/延性组合大幅度超越了已公开报道的钼合金材料，分析表明该材料室温强韧化的关键在于细晶钼基体上的氧化镧颗粒具有晶内/晶界双尺度分布特征。目前该钼合金的高温强韧化的潜力与强韧化机制尚不明确，亟待开展系统的研究。本项目拟设计并制备不同氧化镧含量与晶内/晶界分布权重的钼合金，通过对微观组织结构的定量表征，以及室温/高温力学性能的测试，系统研究不同温度下晶内/晶界双尺度分布氧化镧掺杂钼合金微观组织变化对合金变形行为与力学性能的影响规律，建立微观组织与力学性能之间的联系，揭示双尺度分布稀土氧化物颗粒对钼合金高温稳定性的影响机制，阐明晶内/晶界双尺度分布颗粒的高温强韧化机制及其耦合作用。研究结果将确定双尺寸分布钼合金强韧化的最佳适用温度范围，并为获得应用温度范围更广泛的高强韧钼合金的微观组织优化设计与制备提供实验数据和理论基础。

Recently, we have developed a new kind of high-performance nanostructured molybdenum alloys doped by lanthanum oxide particles. These new alloys possess strength/ductility combination superior to all the reported Mo-based alloys, and the characteristic microstructure of intergranular/intragranular dual lanthanum oxide particles distributed on the ultrafine Mo grains is found to be responsible for the simultaneous improve in strength and ductility. However, the high-temperature mechanical behaviors and strengthening/toughening mechanisms of the new Mo alloys are still unclear. In this project, high-temperature mechanical behaviors of Mo alloys will be systematically investigated, aiming to reveal the temperature-dependent strengthening/toughening mechanisms of the intergranular and intragranular particles, solely and in combination. For this purpose, the doped lanthanum oxide particles will be varied in content and distribution (intergranular/intragranular content ratio) by carefully controlling the preparation technique. Microstructure will be quantatively characterized and related to the room and high temperature mechanical properties, respectively. Through the establishment of relationship between the microstructure and mechanical properties, the effect of dual-scale particles on the high temperature structural stability and high temperature strengthening and toughening mechanisms is expected to be revealed. The research results will be helpful for the determination of the suitable application temperature range of the dual-scale distribution rare oxide dispersion strengthened molybdenum alloy, and also provide experimental data and the theoretical basis for microstructure optimization design and preparation of high-performance molybdenum alloy with the wider application temperature range.