SUN Y C, CHEN Z F, XU Z,et al.Effect of Mn and Zr composite microalloying on the microstructure and mechanical properties of 6061 aluminum alloy cast-rolling plate[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(6):194-200.

doi:10.16186/j.cnki.1673-9787.2023120081

Received:2023/12/31

Revised:2024/03/04

Published:2024-09-24

Effect of Mn and Zr composite microalloying on the microstructure and mechanical properties of 6061 aluminum alloy cast-rolling plate

SUN Yuchong1, CHEN Zefu1, XU Zhen1, TIAN Shuang1, LIU Zhimin1, ZHANG Wei1,2

1.School of Materials and Metallurgy，University of Science and Technology Liaoning，Anshan  114051，Liaoning，China；2.Liaoning Zhongwang Group Co.，Ltd.，Liaoyang  111003，Liaoning，China

Abstract:  Objectives To explore the effect of Mn and Zr composite microalloying on the microstructure and mechanical properties of 6061 aluminum alloy cast-rolling plates， three types of 6061 aluminum alloy cast-rolling plates with different compositions were prepared： the original 6061 aluminum alloy plate， the 6061-0.4Mn aluminum alloy plate with Mn added alone， and the 6061-0.4Mn-0.3Zr aluminum alloy plate with Mn and Zr added.  Methods  The microstructure and properties of the three types of 6061 aluminum alloy cast-rolling plates were studied using electron backscattered diffraction （EBSD）， scanning electron microscopy （SEM）， room temperature tensile tests， and tensile fracture surface analysis.  Results  The results showed that Mn could refine the grain structure of the 6061 aluminum alloy cast-rolling plates， increase the proportion of small-angle grain boundaries， and inhibit recrystallization. Mn also promoted the transformation of the AlFeSi phase to the α-AlFeMnSi phase， improved the morphology of the AlFeSi phase， reduced its volume fraction， inhibited its aggregation， and encouraged its dispersion. Room temperature tensile tests and fracture surface analysis revealed that while the addition of Mn alone improved the strength of the 6061 aluminum alloy cast-rolling plates， it significantly reduced plasticity， making the fractures brittle. In contrast， composite microalloying with Mn and Zr significantly reduced the proportion of small-angle grain boundaries and enhanced the inhibition of recrystallization. of the microstructure of 6061 aluminum alloy cast-rolling plate. The formation of ｛100｝<001> Cube texture in the microstructure achieved texture strengthening， further improving both strength and plasticity， with fractures exhibiting toughness.  Conclusions  The comprehensive mechanical properties of the Mn and Zr composite microalloyed 6061 aluminum alloy cast-rolling plates were superior. Compared to the plates with 0.4 wt.% Mn alone， the tensile strength， yield strength， and elongation increased by 18.8%， 37.8%， and 59.5%， respectively.

Key words:6061 aluminum alloy;microalloying;casting and rolling;texture strengthening