大塑性变形稀土高密度钨合金强韧化机理及应用基础研究

The fabrication technique of high strength and toughness with large length to diameter ratio of tungsten heavy alloy is the urgent need for manufacturing high-performance penetrator. It is difficult to solve the preparation of such materials with high strength and toughness by using the traditional plastic forming manufacturing technology. In order to solve the problem, a novel method of severe plastic deformation is proposed to produce rare earth tungsten alloy with high strength and toughness. On the one hand, vacuum hot-pressing sintering, hot-hydrostatic extrusion and solution and aging treatment are studied to find the effect of rare earth on the law of microstructure and mechanical properties. Influencing mechanism of strengthening and toughening by using severe plastic deformation method about rare earth and the effect of refined crystalline strengthening and work hardening on mechanical properties are revealed. On the other hand, the effect of phase transformation law of solid solution and aging alloy on mechanical properties is studied in order to find the strengthening mechanism. At the same time, the effect of solution and aging treatment on final performance of billets is also researched. Thus, influencing mechanism of strengthening and toughening of rare earth tungsten alloy produced by severe plastic deformation is revealed and the control methods of strengthening and toughening are mastered finally. The scientific significance of this research is to develop the theory of tungsten alloy preparation by using severe plastic deformation, expand basic theory of refractory metal preparation, breakthrough the bottleneck in preparation of high performance powder metallurgy materials, promote the development of cross-discipline among materials, chemistry, physics, mathematics and mechanicals. The investigation will provide a theoretical foundation and a technical support for its application in new-typed armor-piercing weaponry system.

大长径比、高强韧高密度钨合金制备技术，是制造高性能穿甲弹的迫切需要。传统塑性成形制造技术难以解决制备此类构件时的高强韧性需求。为解决上述难题，本项目提出大塑性变形制备高强韧稀土钨合金新方法。一方面通过研究稀土在真空热压烧结、热静液挤压及固溶时效热处理过程中对力学性能及微观组织影响规律，揭示稀土对大塑性变形钨合金的强韧化影响机制，寻找细晶强化和形变强化对合金力学性能影响规律。另一方面，研究固溶时效合金相变规律及对力学性能影响规律，从而弄清楚其强化机理，寻找固溶时效处理对合金最终性能的影响规律，揭示大塑性变形稀土高密度钨合金的强韧化影响机制，最终掌握强韧化控制手段。本课题研究的科学意义在于发展了大塑性变形钨合金制备理论，拓展了难熔金属材料的制备基础理论，突破了高性能粉末冶金材料的制备瓶颈，拓展了本学科与材料、化学、物理、数学、机械学科的交叉发展，为新一代穿甲武器应用提供理论基础和技术支持。

大长径比、高强韧高密度钨合金制备技术，是制造高性能杆式动能穿甲弹弹芯材料的迫切需要。传统塑性成形制造技术难以解决制备此类材料的高强韧性需求。为解决上述难题，本项目提出大塑性变形制备高强韧钨合金新方法。一方面通过研究真空热压烧结、热静液挤压及固溶时效热处理过程中对力学性能及微观组织影响规律，揭示大塑性变形钨合金的强韧化影响机制，寻找细晶强化和形变强化以及固溶强化对合金力学性能影响规律。另一方面，研究固溶时效合金相变规律及对力学性能影响规律，从而弄清楚其强化机理，寻找固溶时效处理对合金最终性能的影响规律，揭示大塑性变形稀土高密度钨合金的强韧化影响机制，最终掌握强韧化控制手段。本课题研究的科学意义在于发展了大塑性变形钨合金制备理论，拓展了难熔金属材料的制备基础理论，突破了高性能粉末冶金材料的制备难题，发现了钨合金在高于400℃时高温力学性能降低的原因，拓展了本学科与材料、化学、物理、数学、机械学科的交叉发展，为新一代穿甲武器应用提供理论基础和技术支持。