大应变交叉轧制Al-9Mg-1.8Li合金板材的显微组织及织构特征

Cross rolling of large strain on microstructure and texture characteristic of Al-9Mg-1.8Li alloy sheet

采用金相显微镜(OM)、透射电镜(TEM)、电子背散射成像技术(EBSD)和X射线,对比分析喷射成形Al-9Mg-1.8Li合金交叉轧制态板材与挤压态板材的微结构及织构特征,并测试板材的拉伸性能和深冲性能。结果表明:大变形量交叉轧制促进动态再结晶的发生,细化晶粒组织,改善再结晶晶粒的择优取向;与CBA和CCB轧制方式相比较,CBB轧制方式显著降低挤压态合金中典型的Brass织构{110}?112?的取向密度,在β取向线上CBB轧制态板材中的Copper织构{112}?111?取向密度最低,且板材中没有典型的织构特征;同时,CBB轧制态合金板材的具有更好的深冲性能,在0°、45°和90°方向的力学性能基本一致,其室温拉伸强度、屈服强度和伸长率分别在611 MPa、507 MPa和20.6%以上。

The metallographic microscope（OM）, transmission electron microscopy（TEM）, electron backscatter imaging（EBSD） and X-ray diffraction were used to analyze the microstructure and texture characteristics of Al-9Mg-1.8Li alloy cross-rolling and extruded plates, and the tensile properties and deep drawing performance were measured. The results show that the cross rolling of large reductions promotes the occurrence of dynamic recrystallization, makes the grains finer and improves the preferential orientation of recrystallized grains. Compared with CBA and CCB rolling methods, the CBB rolling method reduces the orientation density of the typical brass texture {110} 〈112〉 in the extruded alloy, and theorientation density of copper texture {112} 〈111〉 along the β orientation line in the CBB rolling plate is the lowest in the plate. There is no typical texture feature. At the same time, the mechanical properties of CBB rolled alloy plate have better deep drawing performance, and the mechanical properties in the three directions of 0°, 45° and 90° are nearly the same. The room temperature tensile strength, yield strength and elongation are above 611 MPa, 507 MPa and 20.6%, respectively.