Sm对Mg-6Al-1.2Y-0.9Nd合金组织和性能的影响

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

摘要:

采用XRD、OM、SEM和EDS等手段研究Sm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，合金中加入Sm后，Sm优先与A1形成高熔点Al2Sm弥散颗粒质点，当Sm含量(1.5%~2.0%)较高时，合金内出现针状Mg12Nd相。在研究范围内，随Sm含量的增加，合金的常温和高温力学性能略有升高然后降低；而合金的延伸率呈现不断降低的趋势。合金的拉伸断口为具有塑性特征的准解理断裂。

Abstract:

Microstructures and mechanical properties of Mg-6Al-1.2Y-0.9Nd magnesium alloy with Sm addition were investigated through OM, SEM, EDS and XRD. The results show that Sm combines firstly with Al to form dispersed, high-melting-point particles which are mainly Al2Sm phase. When the mass fraction of Sm is high from 1.5% to 2.0%, the acicular Mg12Nd phase appears in the alloy. With the increase of Sm content within the range from 0 to 2.0%, the tensile strength of alloys at ambient and elevated temperature firstly increases slightly, and then decreases; while the elongation decreases continuously. The tensile fracture of the alloy is quasi-cleavage failure with plastic characteristic.