Enhanced stretch formability at room temperature for Mg-Al-Zn/Mg-Y laminated composite via porthole die extrusion

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2018-07, Vol.731, p.184-194
• Main Authors: Wang, Qinghang, Shen, Yaqun, Jiang, Bin, Tang, Aitao, Song, Jiangfeng, Jiang, Zhongtao, Yang, Tianhao, Huang, Guangsheng, Pan, Fusheng
• Format: Article
• Language: English
• Subjects: Aluminum; AZ31/W0 laminated composite; Bimetals; Crystallography; Extrusion dies; Formability; Magnesium base alloys; Porthole die extrusion; Room temperature; Stretch formability; Stretch forming; Twinning; Zinc
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2018.06.055

In this work, Mg-3Al-1Zn/Mg-0.3Y (AZ31/W0) laminated composite sheet was successfully fabricated by porthole die extrusion. Herein, microstructures, textures and stretch formability at room temperature of the AZ31 sheet, the W0 sheet and AZ31/W0 laminated composite sheet were systematically investigated and compared. The results showed that a tiny diffusion zone of ~ 0.35 µm and crystallographic interface were observed in the AZ31/W0 interface, indicating that the AZ31/W0 laminated composite sheet had a well bonding interface. The stretch formability at room temperature of the AZ31/W0 laminated composite sheet was apparently improved by ~ 71% and ~ 20%, respectively, as compared with the AZ31 sheet and W0 sheet. The activation of more basal slip in the W0 layer of the AZ31/W0 laminated composite sheet and the formation of extensive tensile twins in the AZ31 layer, which could effectively accommodate through-thickness strain during stretch forming, were assumed to be the main contribution to the stretch formability enhancement. Therefore, the bimetal laminated composite sheet provided a new thought to achieve high stretch formability Mg alloys via the porthole die extrusion.