稀土元素钇对Al-30wt% Mg_2Si复合材料组织和力学性能的影响

Influence of rare earth element Y on microstructure and mechanical properties of Al-30wt% Mg_2Si composites

利用原位内生工艺制备了Al-30wt%Mg2Si复合材料,并加入不同含量的稀土元素钇(Y)对其进行细化改性,以研究Y对复合材料显微组织和力学性能的影响,及Y对Al-30wt%Mg2Si复合材料的细化机制。结果表明:Y的加入量由0增加至0.8wt%时,初生相Mg2Si的平均晶粒尺寸先减小后变大,而强度、布氏硬度和伸长率先提高后降低;当Y的加入量为0.6wt%时,Al-30wt%Mg2Si复合材料的细化效果最明显,力学性能提高最为显著,抗拉强度由145.5 MPa提高到175.2 MPa;屈服强度由128.8 MPa提高到152.0 MPa,布氏硬度由HB101.4提高到HB129.4;伸长率由2.4%提高到3.3%。

The A1-30wt% Mg2Si composites were made by in-situ process and modified by adding rare earth ele- ment yittium （Y） with different contents, in order to investigate the effects of Y on microstructure and mechanical properties of composites and the refinement mechanism of Y on A1-30wt% Mg2Si composites. The results show that, the average grain size of primary phase Mg2 Si decreases firstly then increases; but the strength, Brinell hard- ness and elongation increase firstly then decrease, when the addition amount of Y increases from 0 to 0.8wt%. With 0.6wt% addition amount of Y, refining effect of A1-30wtM Mg2Si composites is most obvious and the mechanical properties increase observably. Tensile strength increases from 145.5 MPa to 175.2 MPa, yield strength increases from 128.8 MPa to 152.0 MPa, Brinell hardness increases from HB101.4 to HB129.4, elongation increases from 2.4% to 3.3%.