难变形材料大型复杂构件整体/局部加载宏微观变形机理研究报告

杨合　孙志超　陈康华

摘要：针对大型复杂构件整体局部塑变成形与晶体缺陷组态调控的关键科学问题，开展了深入的研究，研究的主要创新如下： 1）揭示了TA15钛合金局部加载多道次宏观不均匀变形模式和规律，探明了局部加载方式等因素与不均匀变形协调及成形缺陷的关联关系，提出了控制成形缺陷的方法；揭示了TA15钛合金等温多道次变形行为和组织演变机理、片层组织动/静态球化机制与规律，建立了球化动力学模型；发明了模拟钛合金复杂大件成形过程过渡区微观组织演化的物理方法，获得了等温局部加载下TA15钛合金不均匀变形加载道次、冷却方式、热处理对加载区与过渡区微观组织演化影响机制；建立了预测钛合金宏观变形响应与微观组织演化的内变量模型、不均匀变形微观机理与织构演化的微观相组分模型和微观组织形态演化的元胞机模型。上述成果为钛合金复杂大件局部加载成形过程优化控制提供了理论和技术基础。 2）揭示了7085铝合金热变形行为和再结晶的影响规律，建立了不同热处理状态7085铝合金的本构方程及热加工图；揭示了成形参数对7085铝合金变形和固溶再结晶的影响规律，建立了合金变形-固溶再结晶图、再结晶模型，确定了不发生变形和固溶再结晶的形变-固溶回复区，提出可以抑制再结晶的拔长-退火-再拔长准等温工艺，可提高强度、塑性、断裂韧性和耐蚀性；建立了7085铝合金多向自由锻、等温模锻成形仿真系统和实验平台。该工作为铝合金复杂构件整体成形提供依据。

关键词：大型复杂构件；整体；局部加载；不均匀变形；微观组织

Abstract：Conducting in-depth research for the key scientific problems of integral/local plastic forming and crystal defect configuration control for large complex components. Completing research content of first two years and achieving research target with part of excess. Main innovations are as follows： 1） Revealing the unequal deformation rule of TA15 Ti-alloy under multi-pass local loading， uncovering relationships between local loading modes with unequal deformation coordination and forming defects， inventing a method for forming defects control. Revealing multi-pass isothermal deformation behavior and microstructur evolution mechanism of TA15， dynamic/static spheroidizing mechanism and law of lamellar structure， establishing spheroidizing dynamics model. Putting forward a physical method to simulate microstructure evolution of transitional zone， obtaining the affacting mechanism of loading pass， cooling， and heat treatment on the microstructure evolution of loading/transitional zones. Establishing Internal-state-variable model， microscopic phase component model， and cellular automata model. The results provide a theoretical and technical basis for forming process optimization and control of Ti-alloy large complex component. 2） Revealing the hot deformation behavior and the recrystallization law of AA7085 al-alloy， developing constitutive equations and hot working diagrams. Revealing the effects of forming parameters on the deformation and solid solution recrystallization of AA7085， establishing deformation-solid solution recrystallization diagram and model. Determining the deformation-solid solution area within it no deformation/solid solution recrystallization occurring. Putting forward a puling-annealing-pulling quasi isothermal process to inhibit recrystallization， which can improve the strength， plasticity， fracture toughness and corrosion resistance. Developing simulation system and experimental platform for AA7085 multidirectional free forging and isothermal forging. 13 invention patents were applied and 5 have been obtained. won one National Science & Technology Progress Award （second class） in 2011. 61 academic papers were published including 28 indexed by SCI， 1 in the TOP1 journal of international forming manufacturing field， IJP （IF > 5）， 2 in Science China， 1 Cover Story in Materials China， 12 in MSE/JMPT/CMS （IF >1）， 6 of IF > 2， 9 invited presentations in conferences. Cultivating 32graduate students （12 PhD students， 20 Master）， 20 graduated.

Keywords：large complex components； integral； localloading； unequal deformation； microstructure