Microstructures and properties of Al-Zn-Mg-Mn alloy with trace amounts of Sc and Zr

作者：Li, Bo; Pan, Qinglin^*; Huang, Xing; Yin, Zhimin

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2014, 616: 219-228.

DOI：10.1016/j.msea.2014.08.024

• Aluminum alloys
• Al-3(Sc, Zr) particles
• Recrystallization
• Mechanical properties
• Corrosion resistance

Microstructures and properties of Al-Zn-Mg-Mn alloy with trace amounts of Sc and Zr have been investigated. The results show that the addition of minor Sc and Zr to Al-Zn-Mg-Mn alloy can effectively refine grain size caused by the formation of Al-3(Sc, Zr) particles with cubic Ll(2) structure, which is coherent with alpha(Al) matrix. After solution treatment at 470 degrees C for 1 h, more homogenous recrystallizadon grains are observed in Al-Zn-Mg-Mn alloy; partial recrystallization occurs in Al-Zn-Mg-Mn-0.12Sc-0.12Zr alloy. However, Al-Zn-Mg-Mn-0.24Sc-0.12Zr alloy still remains an unrecrystallized fiber-like structure, which reveals that minor Sc and Zr can remarkably inhibit the occurrence of recrystallization. After aging treatment at 24 h for 120 degrees C, the tensile strength of Al-Zn-Mg-Mn-0.12Sc-0.12Zr alloy increased by 40 MPa as compared to Al-Zn-Mg-Mn alloy. When the Sc content increased to 0.24 wt%, the tensile strength of Al-Zn-Mg-Mn-0.24Sc-0.12Zr alloy reached a maximum. The main strength mechanisms are grain refinement strengthening with combined Sc and Zr additions and precipitation strengthening of Al-3(Sc, Zr) particles. Compared with Al-Zn-Mg-Mn alloy, Al-Zn-Mg-Mn alloy with trace amounts of Sc and Zr exhibits higher corrosion resistance due to the discontinuity distribution of 11 precipitates along the grain boundary and the resistance effect on recrystallization behavior by Al-3(Sc,Zr) particles. 2014 Elsevier B.V.

• 出版日期2014-10-20
• 单位中南大学