Mn含量对Mg-5Al合金铸态组织和力学性能的影响

研究了合金元素Mn对Mg-5Al合金铸态组织和力学性能的影响。结果表明,在Mg-5Al合金中加入Mn后,合金组织细化,连续或半连续网状分布的β-Mg17Al12相逐渐转变为断续、分散的骨骼状相,晶界附近出现颗粒相并且数量逐渐增多。随着Mn含量增加,合金室温抗拉强度、伸长率及冲击韧度先上升然后下降。当Mn含量为0.3%时,合金综合力学性能最好,抗拉强度、伸长率与冲击韧度达到190MPa、7.3%与21.1J·cm-2,分别提高了7.9%、9.1%与9.3%。继续增加Mn含量至0.5%时,Al8Mn5颗粒聚集长大粗化,导致Mg-5Al合金综合力学性能下降。

Effects of Mn Addition on Microstructure and Mechanical Properties of As-cast Mg-5Al Magneisum Alloy

Effects of Mn addition on the microstructure and mechanical properties of as-cast Mg-5Al magnesium alloy were investigated.The results show that with Mn addition,grain size in the alloy is refined,and continuous or semi-continuous net-like β-Mg17Al12 phase are converted into discontinuous and dispersedly skeleton one,meanwhile,particle phase is generated in the grain boundary with increasing in numbers.With increasing in Mn addition,ambient tensile strength,elongation and impact toughness of the alloy exhibit firstly increase and then decrease.When Mn addition reaches 0.3%,tensile strength,elongation and impact toughness reach 190 MPa,7.3% and 21.1 J·cm-2,increased by 7.9%,9.1% and 9.3%,respectively.With increasing Mn addition to 0.5%,comprehensive mechanical properties of the alloy are deteriorated as a result of aggregation and coarseness of Al8Mn5 particle.