Mn对挤压态Al-Li-Zr-Sc合金组织性能的影响

Effects of Mn on Microstructure and Properties of Extruded Al-Li-Zr-Sc Alloys

采用真空熔炼铸造及热挤压方法制备了Al-3Li-0.1Zr-0.1Sc-xMn(x=0,1.2,5,质量分数,%)合金。通过金相显微镜、扫描电镜、拉伸性能、维氏硬度、纳米压痕等测试方法,研究了Mn的添加对合金强度、弹性模量及显微组织的影响。结果表明,Mn的添加缩短了合金的时效硬化过程,提高了合金硬度,促进合金中δ′-Al3Li相的时效析出。Mn含量为1.2%时,Al-3Li-0.1Zr-0.1Sc-1.2Mn合金的抗拉强度达到536 MPa,弹性模量达到82.7 GPa,比模量达到32.4 GPa·cm3/g。此外,讨论了固溶体及第二相与合金弹性模量的关系。

Al-3Li-0.1Zr-0.1Sc-xMn(x=0,1.2,5,%)alloys were prepared by vacuum melting and hot extrusion.The effects of Mn addition on microstructure and properties of the alloys were investigated by optical microscope,scanning electron microscope,tensile test,Vickers hardness and nano-indentation.The results indicate that Mn addition can significantly shorten the aging hardening process and increase the hardness of alloy,promoting the aging precipitation ofδ′-Al_3Li phase.When the content of Mn is 1.2%,the tensile strength,modulus and specific modulus of Al-3Li-0.1Zr-0.1Sc-1.2Mn alloy reach 536 MPa,82.67 GPa and 32.42 GPa·cm~3/g,respectively.Moreover,the relationship between elastic modulus and solid solution or second phase were discussed.