Mn对Al-Mg-Si-Cu铝合金车身板组织和性能的影响

Effect of Mn Addition on Microstructures and Properties of Al-Mg-Si-Cu System Alloys for Automotive Body Sheets

通过拉伸和埃里克森实验以及扫描电镜/能谱、透射电镜和金相分析,研究Mn的质量分数对Al Mg Si Cu铝合金汽车板显微组织、力学性能和成形性的影响·研究表明,随Mn质量分数增加,Al Mg Si Cu汽车板铝合金不可溶结晶相及弥散相粒子数量均增加,不可溶结晶相使合金组织纤维化对板材冲压成形性不利,弥散相粒子阻碍再结晶晶粒长大;提高Mn的质量分数,Al Mg Si Cu汽车板铝合金的强度增加,但延伸率和冲压成形性降低·

By means of scan electron microscope (SEM), energy dispersive spectrum (EDS), transmission electron microscope (TEM), metallographic analysis, tensile and Ericsson tests, the effect of variation of the addition Mn content on the microstructures, tensile properties and formabilities of Al-Mg-Si-Cu system alloys for automotive body sheets were investigated. The results indicated that the numbers of insoluble constituents and dispersoids particles both increase with the increasing mass fraction of Mn in the alloys. The insolube constituents of the distribution with continuous line in microstructures is unfavourable to the pressing formability of automotive body sheets, whereas the dispersoid particles will inhibit the growth of grains during recrystallization. Therefore, increasing the Mn mass fraction will improve the strength of the alloys but reduce their percentage elongation and pressing formability.