论文部分内容阅读
采用冷轧、预热处理和等通道转角挤压制备了超细晶铝。利用室温单轴拉伸测试、扫描电镜和X射线衍射技术研究了预热处理对超细晶铝力学性能的影响。结果表明,630℃预热处理时采用空冷、炉冷、水冷3类冷却方式试样的抗拉强度分别达到130、160和180 MPa,而伸长率降低到3.2%、3.9%和2.8%。试样的拉伸断裂处形成了大小不均的韧窝。预热处理时不同冷却方式造成的再结晶晶粒尺寸和晶界特征的不同是导致材料力学性能产生明显差异的主要原因。
Ultrafine-grained aluminum was prepared by cold rolling, pre-heat treatment and isocenter angular extrusion. The effects of preheating treatment on the mechanical properties of ultrafine-grained aluminum were studied by uniaxial tensile test, scanning electron microscopy and X-ray diffraction. The results show that the tensile strength of the specimens cooled by air cooling, heat - cooling and water cooling are 130, 160 and 180 MPa respectively at 630 ℃, while the elongation is reduced to 3.2%, 3.9% and 2.8% respectively. Tensile fracture of the sample formed dimples of unequal size. The difference of recrystallization grain size and grain boundary characteristic caused by different cooling methods during preheating treatment is the main reason that leads to the significant difference of material mechanical properties.