Sc、Zr复合添加对7085铝合金组织与性能的影响

Effects of Sc and Zr Compound Addition on Microstructure and Properties of 7085 Aluminum Alloy

通过金相显微镜、背散射电子衍射(EBSD)和拉伸力学测试,研究了Sc和Zr元素对7085铝合金组织与性能的影响。结果表明,Sc、Zr具有很强的晶粒细化效果,添加Zr可使铸态晶粒尺寸减小46.7%,添加Sc可减小51.4%,复合添加Sc、Zr效果最佳可减小58.1%。同时,Sc、Zr在合金中会生成Al3Sc和Al3Zr,具有很强的抑制再结晶作用。经轧制、固溶时效后,未添加Sc、Zr的合金会完全再结晶,仅添加Zr的合金再结晶程度为60%,添加Sc和Sc、Zr复合添加的合金再结晶程度非常低,仅约为5%。因此,复合添加Sc、Zr可大幅提高合金的力学性能,在相同工艺条件下,其抗拉强度达606 MPa,比未添加Sc、Zr的合金提高17.6%。

The effects of Sc and Zr element on the microstructure and mechanical properties of 7085 aluminum alloy were studied by optimal microscope, electron back-scattered diffraction(EBSD) and tensile testing. The results show that Sc and Zr have good grain refinement effect. The addition of Zr can decrease the as cast grain size by 46.7%, and the addition of Sc can decrease the grain size by 51.4%. The multiple addition of Sc and Zr can decrease the grain size by 58.1%, which is the best. Meanwhile, by adding Sc and Zr, Al3 Sc and Al3 Zr precipitate in the materials, which is good for the recrystallization restrain. After rolling solid solution and aging, the complete recrystallization takes place in the material without Sc and Zr, the recrystallization degree of the alloys by adding Zr is 60%, and the recrystallization degree of the alloys by adding Sc, and multiple adding Sc and Zr is the lowest, which is 5%. Hence, by multiple adding Sc and Zr, the mechanical properties of the alloy greatly improves, and under the same processing condition, the tensile strength is 606 MPa, which is 17.6% higher than that of the alloy without adding Sc or Zr.