氦对金属力学性能影响机理的计算机模拟研究

Titanium has wide application prospects in the nuclear technology fields such as structural materials for nuclear reactor, tritium storage materials and so on. However, the introduction of helium into metal is a universal and inevitable problem until now. Due to its extremely low solubility, helium atoms in metal prefer to migrate and accumulate to form bubbles, and finally release from the material, which could degrade the structural and mechanical properties of material evidently. This series of macro problems introduced by helium have not been solved so far. In this project, aim for the physical mechanism of effect on metal mechanical properties introduced by helium, microscopic behavior of helium atoms in Ti single crystal and Ti sample including grain boundary, respectively, and the effects on tensile mechanical properties of the both Ti samples introduced by helium atoms are investigated through computer simulation methods. And these researches are of great advantage to the solution of aging and failure of materials containing helium, and then are very significant for the development of nuclear power industry and relevant military industry.

金属Ti在反应堆结构材料及储氚材料等核能技术领域，具有非常广阔的应用前景，然而，金属材料中He的引入目前是一个普遍存在且不可避免的重要问题。He在金属材料中溶解度极低，极易迁移、聚集、成泡，最终破裂释放，从而导致金属材料的结构及力学性能等明显下降，且到目前为止由He引发的一系列宏观现象尚未得到有效解决。本项目以He对金属Ti力学性能影响的物理机理为出发点，采用计算机模拟方法，分别研究了金属Ti单晶与含晶界金属Ti中He的微观行为，及杂质He原子对两种金属样品拉伸力学性能的影响。将He原子在金属Ti中的演化行为及其对Ti力学性能的影响机制阐述清楚，对含He材料的老化、失效等问题的解决大有裨益，进而对核能工业和有关军事工业的发展具有十分重要的意义。

金属Ti在反应堆结构材料及储氚材料等核能技术领域，具有非常广阔的应用前景，然而，金属材料中He的引入目前是一个普遍存在且不可避免的重要问题。He在金属材料中溶解度极低，极易迁移、聚集、成泡，最终破裂释放，从而导致金属材料的结构及力学性能等明显下降，且到目前为止由He引发的一系列宏观现象尚未得到有效解决。通过本项目的研究，掌握了金属Ti中He的迁移、聚集规律，阐明了材料中He泡的成核机理，掌握了金属Ti中He 泡破裂释放的的影响因素，揭示了材料中He 泡释放的物理机制。另外，通过对比金属Ti单晶与含晶界金属Ti的模拟结果，分析了材料结构对He行为的影响，掌握了He在不同结构金属中迁移、聚集、成核及破裂释放的差异，并阐明了这种差异产生的原因及机制。最后还研究了He对金属Ti力学性能的影响，阐明了金属Ti力学性质变化的物理机制及影响因素，为已有实验结果提供佐证与理论解释。