稀土元素La对Al-4．2％Cu-1．5％Mg合金显微组织及拉伸性能的影响

Effect of Rare Earth Element La on Microstructures and Tensile Properties of Al-4. 2%Cu-1. 5%Mg Alloys

通过进行金相显微镜和扫描电镜观察与拉伸性能测试等，研究了稀土La的添加对挤压态与固溶态Al-4．2％Cu-1．5％Mg合金的显微组织与拉伸性能的影响。结果表明，对于挤压态和固溶态Al-4．2％Cu-1．5％Mg合金而言，添加适量的La可使合金的显微组织得到细化，屈服强度得到提高，塑性有所改善。此外，固溶处理可以显著提高Al—4．2％Cu-1．5％Mg-xLa（x=0,0．1％，0．3％）合金的屈服强度和抗拉强度。

The effect of rare earth La on both microstructures and mechanical properties of extruded and solid-solution treated Al-4. 2%Cu-1. 5%Mg alloys were investigated through performing the tensile test and microstructural observations with both optical microscope and scanning electron microscope. The results show that the microstructures of both extruded and solid-solution treated Al-4. 2%Cu-1. 5%Mg alloys get refined through adding the moderate quantity of rare earth element La, the yield strength of the alloys gets enhanced, and the plasticity of the alloys gets improved as well. In addition, the solid -solution treatment can significantly improve both yield and ultimate tensile strengths of the Al-4. 2%Cu-1. 5%Mg -xLa （x=0, 0.1%, 0.3%） alloys.