轧制铝合金板材剪切与反剪切力学性能的研究

Research on Shear and Reverse Shear Mechanical Properties of Rolled Aluminum Alloy Sheet

通过自行设计制造的剪切试验装置,开展交通工具中常用的5052-H32、6061-T6、7075-T651三种铝合金板材的剪切与反剪切力学性能、组织的变化规律研究。结果表明:在板材剪切变形强化和板材原始轧制缺陷的共同作用下,三种牌号铝合金随着板材厚度的增加,板材的抗剪强度均呈现出先增大再减小的变化规律;板材厚度为2 mm的三种铝合金在预变形-反剪切试验时其反剪切强度均明显低于单向剪切强度,而当板材厚度为4 mm和6 mm时,上述现象不明显。通过对比单向剪切与反剪切的断口SEM形貌可以看出,反剪切的断口中单个滑移平面的面积明显增大,而且滑移平面更加光滑、平整。

The shear and reverse shear mechanical properties and microstructure of 5052-H32,6061-T6 and 7075-T651 aluminum alloy sheets commonly used in vehicles were studied by using a self-designed shear test device.The results show that under the combined action of sheet shear deformation strengthening and sheet original rolling defects,with the increase of sheet thickness,the shear strength of the three grades of aluminum alloys all show a change law that first increases and then decreases.In the pre-deformation-reverse shear test of the three aluminum alloys with a plate thickness of 2mm,the reverse shear strength of the three aluminum alloy plates is significantly lower than the unidirectional shear strength.When the sheet thickness is 4 mm and 6 mm,the above phenomenon is not obvious.By comparing the SEM morphology of the fractures of unidirectional shear and reverse shear,it can be seen that the area of a single slip plane in the fracture of reverse shear is significantly increased,and the slip plane is smoother and flatter.