LaCe混合稀土对过共晶A390合金微观组织和力学性能的影响

Effect of LaCe Mischmetal on Microstructure and Mechanical Properties of Hypereutectic A390 Alloy

采用LaCe混合稀土对过共晶A390合金进行变质处理,并对变质前后合金的微观组织和力学性能进行测试。研究结果表明0.5%的LaCe混合稀土能够有效细化合金组织,经过变质处理后初生硅尺寸由40～60μm减小到10～30μm。X射线衍射分析结果表明变质后的合金有新相生成。变质后合金的抗拉强度从168 MPa提高到232 MPa,伸长率从0.25%提高到1.32%。

LaCe mischmetal was adopted to modify the hypereutectic A390 alloy. The microstructure and mechanical properties of the alloy before and after modification were tested. The results show that the addition of LaCe （0.5 wt%） mischmetal in the alloy can effectively refine the microstructure of the alloy, and the size of primary silicon phase was refined from 40-60 μm to 10-30 μm. The XRD results show that the new phase is formed in the modified alloy. After modification, the tensile strength of the alloy is increased from 168 MPa to 232 MPa, and the elongation is increased from 0.25% to 1.32%.