Ca对Mg-5Li-3Al-2Zn合金组织和力学性能的影响

Effect of Ca on the Microstructures and Mechanical Properties of Mg-5Li-3AI-2Zn Alloys

实验研究了添加1%、2%、3%、6%Ca对Mg-5Li-3Al-2Zn合金组织和性能的影响。通过观察显微组织,利用XRD和EDS分析组织成分可知,添加适量的Ca可细化晶粒,Ca主要富集在晶界处,当Ca加入量超过2%时,与Al形成Al_2Ca金属间化合物,Al_2Ca较多时,对基体的割裂作用较强。室温拉伸试验结果表明,添加2%Ca,强度和塑性同时提高,继续增加Ca含量,合金的力学性能下降。

Ca was added in Mg-5Li-3Al-2Zn alloys to study its effect on the microstructures and properties of alloys, and Ca additive was 1 %, 2%, 3% and 6%. The microstructures of alloys were observed with metallographic microscope. XRD and EDS were used to analyze the microstructures. It is found that Ca addition can produce grain refinement. Ca enriches on the grain boundaries. When Ca addition is larger than 2%, Al2Ca will form in the alloys. Al2Ca is a brittle phase which dissevers the matrix. Mechanical tests were carried out at room temperature. The result shows that both the strength and elongation increase with the increase of Ca addition. When the Ca addition is larger than 2 %, the mechanical properties will be worsened.