【摘要】 采用拉伸试验、断口扫描及透射组织观察等方法,研究了2A12铝合金棒材170℃22 h时效前预拉伸对其组织及性能的影响。结果表明,预拉伸处理可以提高2A12铝合金棒材的强度,随着预拉伸变形量的增加,其屈服强度明显提高,伸长率逐渐降低;2A12铝合金的主要强化相是θ’相,预拉伸产生的位错促进θ’相的析出,因预拉伸量不同使位错的密度和分布发生变化,从而影响θ’相的析出状态,改变合金的力学性能。更多还原

【Abstract】 The effect of pre-stretching on the microstructure and mechanical properties of 2A12 aluminum alloy before 22 h aging at 170℃ was researched by the tensile test,SEM and TEM. The results showed that pre-stretching could increase the tensile strength of 2A12 aluminum alloy bar. Yield strength increased obviously and elongation decreased gradually with the rising of the pre-stretching deformation. The main precipitated phase of 2A12 aluminum alloy was θ’ phase. The dislocation owing to pre-stretching could promote the precipitation of θ’phase. Different distribution and density of the dislocation which was caused by different prestretching affected the θ’ phase status and the θ’ phase affected the mechanical properties.更多还原