Sn对Mg-6Al-1.2Y-0.9Nd镁合金组织和性能的影响

采用XRD、OM、SEM和EDS等手段研究Sn对Mg-6Al-1.2Y-0.9Nd合金微观组织和力学性能的影响。结果表明， Sn可以显著提高合金从室温到175 ℃区间的抗拉强度，当Sn含量为1%时，镁合金在室温和175 ℃时抗拉强度达到最大值，分别为242和192 MPa，合全的拉伸断口为具有塑性特征的准解理断裂。 Sn的加入使合金的显微组织得到明显细化，并出现高熔点Mg2Sn合金相。合金力学性能的提高主要是由于细晶强化、弥散强化和固溶强化。

Effects of Sn on Microstructures and Mechanical Properties of Mg-6Al-1.2Y-0.9Nd Alloys

Microstructures and mechanical properties of Mg-6Al-1.2Y-0.9Nd magnesium alloy with Sn addition were investigated by OM, SEM, EDS and XRD. The results show the addition of Sn can dramatically enhance the tensile strength of the alloy in the temperature range of 25-175 oC. When the content of Sn is up to 1%, the values of tensile strength of the alloy at room temperature and 175 oC are up to their maximums simultaneously, 242 MPa and 192 MPa, respectively. The fracture of the alloy is quasi-cleavage failure with plastic characteristic. It can be found that the grain of alloy is obviously refined with the addition of Sn. The high-melting phases Mg2Sn is found in the alloy with the addition of Sn. Sn can improve the mechanical properties of Mg-6Al-1.2Y-0.9Nd alloy because of the grain?refining?strengthening, solution strengthening and dispersion strengthening.