6061铝合金复合挤压成形微观组织与力学性能的研究

Research on Microstructure and Mechanical Properties of 6061 Aluminum Alloy Formed by Combined Extrusion

对6061铝合金进行了内孔双面凸台复合挤压成形,分析了变形前后试样的显微组织及力学性能变化。结果表明,随着变形程度的增加,试样的径向以及轴向的抗拉强度和硬度增加,但伸长率下降;同一变形下轴向的抗拉强度和硬度高于径向,但伸长率低于径向。在变形前后,6061铝合金各部分的金属流线由直线变成了圆弧状,各部分的晶粒明显细化,且凸台部分的晶粒尺寸相对于径向部分小。复合挤压成形结束后,两侧凸台部分的晶粒形态以及力学性能几乎相同。

Combined extrusion forming of 6061 aluminum alloy with inner hole double-sided bosses was carried out. The microstructure and mechanical properties of the samples before and after deformation were analyzed. The results show that with the increase of deformation degree, the radial and axial tensile strength and hardness increase, but the elongation decreases; under the same deformation, the tensile strength and hardness of the axial direction are higher than those of the radial direction, but the elongation is lower than that of the radial direction. Before and after deformation, the metal streamline of each part of 6061 aluminum alloy changes from straight line to arc shape, the grains of each part are obviously refined, and the grain size of the boss part is smaller than that of the radial part. The grain morphologies and mechanical properties of the boss parts of the two sides are almost the same after the combined extrusion is finished.