预变形对6082铝合金人工时效性能的影响

Effects of pre-deformation on artificial aging properties of 6082 aluminum alloy

探究了预变形对6082铝合金时效析出行为及力学性能的影响。采用万能试验机测试材料的力学性能,通过扫描电镜观察拉伸断口形貌,使用光学显微镜和透射电镜表征微观组织。结果表明:当预变形量为4%时,6082铝合金的屈服强度和抗拉强度达到峰值,分别为324和369 MPa,随预变形量的继续增大逐步下降。6082铝合金的伸长率随着预变形量的增大而不断下降。经不同热处理和预变形的6082铝合金在常温拉伸条件下均表现出韧性断裂。随着预变形量增加,断口处的韧窝尺寸变小,韧窝变浅。预变形有利于析出相的析出,当预变形量为4%时,析出相分布密度最大,尺寸细小。随着预变形量继续增加,析出相分布不均,且尺寸出现粗化,材料的强度和塑性均下降。

The influence of pre-deformation on the aging precipitation behavior and mechanical properties of 6082 aluminum alloy was explored.The mechanical properties of the material were tested using universal testing machine,and the scanning electron microscopy was applied to observe the morphologies of tensile fracture.The optical microscopy and transmission electron microscopy were used to characterize the microstructure.The results show that as the pre-deformation amount reaches 4%,the yield strength and tensile strength of the 6082 aluminum alloy reach the peak values,which are 325 and 369 MPa,respectively.As the pre-deformation amount continues to increas,the yield strength and tensile strength gradually decrease.The elongation of 6082 aluminum alloy gradually decreases with the increase of pre-deformation amount.6082 aluminum alloy under different heat treatments and pre-deformations exhibits ductile fracture under room temperature tensile condition.As the pre-deformation amount increases,the size of the ductile dimples at the fracture surface becomes smaller and shallower.Pre-deformation can effectively promote the precipitation of precipitated phases.When the pre-deformation amount is 4%,the distribution density of precipitates is the highest and the size is small.As the pre-deformation amount continues to increase,the distribution of precipitates is uneven and the size appears coarsening.Both strength and plasticity of the material decrease.