EBSD analysis on restoration mechanism of as-extruded AA2099 Al-Li alloy after various thermomechanical processes
EBSD analysis on restoration mechanism of as-extruded AA2099 Al-Li alloy after various thermomechanical processes
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DOI：
10.1016/j.matchemphys.2017.01.044
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发表时间：
2017-04
影响因子：
4.6
通讯作者：
Xusheng Yang;L. Chai;Wei-jiu Huang;Yanlong Ma;Zhenhao Zhang
中科院分区：
文献类型：
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作者：
Xusheng Yang;L. Chai;Wei-jiu Huang;Yanlong Ma;Zhenhao Zhang
挤压态AA 2099铝锂合金的圆柱形试样在360° C至520° C的温度范围内和0.001 s-1至10 s-1的应变速率范围内进行单轴压缩。建立了这些标本的加工图谱。利用电子背散射衍射（EBSD）技术对不同变形条件下的试件进行了微观结构和修复机理的研究。通过EBSD数据的低角度边界的统计的基础上计算在各种标本的存储能量。储能和取向差的显著降低表明，动态再结晶（DRX）发生在480-520° C和0.001-0.1 s-1。明显的动态再结晶形核进一步表明，该过程应归类为不连续动态再结晶（DDRX）。不同试样的储能对动态回复和动态再结晶的程度有很大影响。通过系统地考虑挤压态AA 2099铝锂合金的加工图和回复行为，确定了挤压态AA 2099铝锂合金的动态再结晶区和中心高η区对应于较佳的热机械加工工艺参数。
Cylindrical specimens of as-extruded AA2099 Al-Li alloy are uniaxially compressed at temperatures ranging from 360° C to 520° C and strain rates ranging from 0.001 s− 1 to 10 s− 1. Processing map of these specimens was established. Electron backscatter diffraction (EBSD) measurements were performed for specimens deformed under various conditions to probe their microstructures and restoration mechanisms. Stored energies in various specimens are calculated based on statistics of low angle boundaries via EBSD data. The remarkable decrement of stored energy and misorientation characteristics reveal that dynamic recrystallization (DRX) happens at 480–520° C and 0.001–0.1 s− 1. Obvious DRX nucleation further suggests that this process should be classified to discontinuous dynamic recrystallization (DDRX). Stored energies in various specimens strongly affect the extents of dynamic recovery and dynamic recrystallization. By systemically considering the processing map and restoration behaviours of the specimens, the dynamic recrystallization regimes and the central high-η regimes are determined to correspond to preferable thermo-mechanical processing parameters for the as-extruded AA2099 Al-Li alloy.