Effects of calcium,samarium addition on microstructure and mechanical properties of AZ61 magnesium alloy

The microstructure and mechanical properties of AZ61 magnesium alloy with Ca, Sm addition were investigated. The results showed that the addition of 0.5 wt.% Ca reduced the quantity of Mg17Al12 phase, and formed a new Al4 Ca phase which is reticular in AZ61 alloy. With the addition of Ca and Sm, the microstructure was further refined and new Al-Sm rich phases were formed in AZ61 alloy with 0.6 wt.%–1.5 wt.% Sm addition, the TEM analysis confirmed that they were Al2 Sm and Al4 Sm. Tensile tests showed that 1.0 wt.% Sm addition contributed to the formation of the Al2 Sm and Al4 Sm and the improvement in the ambient strength, i.e., an ultimate tensile strength of 327 MPa and an elongation of 10.1%. However, excessive Sm addition led to the coarsening of Al2 Sm and Al4 Sm phases, thus resulted in the decline of strength and plasticity.     

Sm、Sb合金化对AZ61组织和性能影响的研究

研究了铸态AZ61-1Sm-xSb合金,并对其进行了热挤压和时效处理（T5）。结果表明,AZ61-1Sm-xSb合金的主要合金相为β-Mg17Al12、Al2Sm、Al3Sm及SbSm。与AZ61相比,AZ61-1Sm中的Mg17Al12相呈现不连续分布的特征;而在AZ61-1Sm中添加Sb,Mg17Al12不连续分布特征更加明显,并且出现针状SbSm相,当 Sb添加量为1.5wt%时出现大块状SbSm相,而β-Mg17Al12、Al2Sm、Al3Sm均为颗粒状并呈弥散分布。Sm和Sb的添加能提高AZ61合金挤压和时效态合金力学性能,而在AZ61-1Sm合金中添加Sb元素能显著提高合金的高温强度。