Sr对AM50显微组织和力学性能的影响

Effect of Sr on Microstructure and Mechanical Properties of AM50

研究了不同含量Sr对AM50合金微观组织和力学性能的影响。结果表明,添加Sr后,AM50合金铸体组织β-Mg17Al12变得细小,晶粒明显细化;Sr基本上与Al结合生成高熔点、高稳定的Al4Sr相,能够强化晶界并阻碍位错滑移,从而强化合金。适量的Sr明显提高了室温下合金的屈服强度和抗拉强度,而且不影响合金的延伸率,而过量的Sr会导致AM50延伸率和轻度的降低。含0.5%Sr的铸态合金可得到最高抗拉强度233MPa,屈服强度90MPa,延伸率16.3%的性能。

The effect of Sr on the microstructure and mechanical properties of AM50 is investigated. The results indicate that the addition of Sr makes refinement of β-Mg17 Aln and grains. Most of Sr reacts with Al to form compounds of Al4 Sr with high melting point and elevated temperature stability which strengthen grain boundaries, hinder dislocation and increase AM50 alloys mechanical properties. The experimental results also show that proper additions of strontium can increase its mechanical properties at ambient temperature significantly, while the ductility of the alloy do not decrease. The mechanical tests indicate that AM50 has the best tensile strength 233MPa when the content of Sr is 0. 5%,its yield strength and elongation are 90MPa and 16.3%.