難變形材料大型復雜構件整體/局部加載宏微觀變形機理研究報告

楊合　孫志超　陳康華

摘要：針對大型復雜構件整體局部塑變成形與晶體缺陷組態調控的關鍵科學問題，開展了深入的研究，研究的主要創新如下： 1）揭示了TA15鈦合金局部加載多道次宏觀不均勻變形模式和規律，探明了局部加載方式等因素與不均勻變形協調及成形缺陷的關聯關系，提出了控制成形缺陷的方法；揭示了TA15鈦合金等溫多道次變形行為和組織演變機理、片層組織動/靜態球化機制與規律，建立了球化動力學模型；發明了模擬鈦合金復雜大件成形過程過渡區微觀組織演化的物理方法，獲得了等溫局部加載下TA15鈦合金不均勻變形加載道次、冷卻方式、熱處理對加載區與過渡區微觀組織演化影響機制；建立了預測鈦合金宏觀變形響應與微觀組織演化的內變量模型、不均勻變形微觀機理與織構演化的微觀相組分模型和微觀組織形態演化的元胞機模型。上述成果為鈦合金復雜大件局部加載成形過程優化控制提供了理論和技術基礎。 2）揭示了7085鋁合金熱變形行為和再結晶的影響規律，建立了不同熱處理狀態7085鋁合金的本構方程及熱加工圖；揭示了成形參數對7085鋁合金變形和固溶再結晶的影響規律，建立了合金變形-固溶再結晶圖、再結晶模型，確定了不發生變形和固溶再結晶的形變-固溶回復區，提出可以抑制再結晶的拔長-退火-再拔長準等溫工藝，可提高強度、塑性、斷裂韌性和耐蝕性；建立了7085鋁合金多向自由鍛、等溫模鍛成形仿真系統和實驗平臺。該工作為鋁合金復雜構件整體成形提供依據。

關鍵詞：大型復雜構件；整體；局部加載；不均勻變形；微觀組織

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