TY - JOUR
T1 - Microstructure evolution difference in Mg96.5Gd2.5Zn1 alloys extruded from as-cast and solution-treated states
AU - Su, Ning
AU - Wu, Yujuan
AU - Zhang, Yu
AU - Cheng, Xiaowei
AU - Peng, Liming
AU - Yang, Kun
AU - Chen, Qiang
N1 - Funding Information:
The present work was supported by the National Key Research and Development Program of China (No. 2016YFB0701201 ), the National Natural Science Foundation (Nos. 51771113 , 51971130 ), the United Fund of National Department of Education and Equipment Development (No. 6141A02033213 ) and the 111 Project (No. B16032 ).
Funding Information:
The present work was supported by the National Key Research and Development Program of China (No. 2016YFB0701201), the National Natural Science Foundation (Nos. 51771113, 51971130), the United Fund of National Department of Education and Equipment Development (No. 6141A02033213) and the 111 Project (No. B16032).
PY - 2020/8
Y1 - 2020/8
N2 - Microstructure evolution and mechanical properties of Mg96.5Gd2.5Zn1 alloys in as-cast and solution-treated states were systematically studied during hot extrusion. The as-cast alloy mainly contains eutectic (Mg,Zn)3Gd compound, block-shaped 18R-LPSO structure and Mg matrix with a few lamellar long-period stacking order (LPSO) structures. The solution-treated alloy has a block-shaped 14H-LPSO structure at grain boundaries (GBs) and high-density lamellar LPSO structures within the matrix. After hot extrusion, the (Mg,Zn)3Gd phase and 18R-LPSO structure were broken an kinked, respectively. Bimodal microstructure with fine recrystallized (DRXed) grains and coarse-deformed grain were formed in both studied alloys. Sandwich-like distribution of the fine DRXed grain was observed in the as-cast-extruded alloy, which shows obviously different DRX behavior compared with the solution-treated-extruded alloy that recrystallizes at GBs. The result reveals that lamellar LPSO structure promotes DRX formation in the LPSO-free region of the matrix by accumulating dislocations at the interface frontier of lamellar LPSO/matrix. Moreover, the LPSO structure, fine DRXed grains and nanoparticles at GBs enhanced the yield strength of the wrought alloy.
AB - Microstructure evolution and mechanical properties of Mg96.5Gd2.5Zn1 alloys in as-cast and solution-treated states were systematically studied during hot extrusion. The as-cast alloy mainly contains eutectic (Mg,Zn)3Gd compound, block-shaped 18R-LPSO structure and Mg matrix with a few lamellar long-period stacking order (LPSO) structures. The solution-treated alloy has a block-shaped 14H-LPSO structure at grain boundaries (GBs) and high-density lamellar LPSO structures within the matrix. After hot extrusion, the (Mg,Zn)3Gd phase and 18R-LPSO structure were broken an kinked, respectively. Bimodal microstructure with fine recrystallized (DRXed) grains and coarse-deformed grain were formed in both studied alloys. Sandwich-like distribution of the fine DRXed grain was observed in the as-cast-extruded alloy, which shows obviously different DRX behavior compared with the solution-treated-extruded alloy that recrystallizes at GBs. The result reveals that lamellar LPSO structure promotes DRX formation in the LPSO-free region of the matrix by accumulating dislocations at the interface frontier of lamellar LPSO/matrix. Moreover, the LPSO structure, fine DRXed grains and nanoparticles at GBs enhanced the yield strength of the wrought alloy.
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U2 - 10.1016/j.jmatprotec.2020.116666
DO - 10.1016/j.jmatprotec.2020.116666
M3 - Article
AN - SCOPUS:85079849655
VL - 282
JO - Journal of Materials Processing Technology
JF - Journal of Materials Processing Technology
SN - 0924-0136
M1 - 116666
ER -