TY - JOUR
T1 - Achieving high strength-ductility of Al-Zn-Mg-Cu alloys via hot-wire arc additive manufacturing enabled by strengthening precipitates
AU - Fu, Rui
AU - Lu, Wenjun
AU - Guo, Yueling
AU - Lei, Hongshuai
AU - Cui, Yinan
AU - Wang, Jiarong
AU - Di Gao, Gao
AU - Wang, Jiachen
AU - Liu, Changmeng
N1 - Publisher Copyright:
© 2022
PY - 2022/10
Y1 - 2022/10
N2 - The Al-Zn-Mg-Cu alloys fabricated by wire arc additive manufacturing (WAAM) have inferior performance due to poor microstructures and inevitable defects, which restrict their development. This study explored the hot-wire arc additive manufacturing (HWAAM) of the 7055 alloy, and proposed a three-stage solution and aging heat treatment method to further improve its mechanical properties. Both as-deposited and heat treated samples were mainly composed of equiaxed grains. Within grains of the as-deposited sample, the Mg(Zn,Cu)2 were precipitated. After heat treatment, apart from the small and abundant Mg(Zn,Cu)2 precipitates, the Al3Zr were also precipitated. Crack-free 7055 alloy parts were obtained, and the low porosity of as-deposited and heat treated samples were 0.18 % and 0.26 %, respectively. In addition, the alternating clustered-pore zones and discrete-pore zones were observed in both samples. After heat treatment, UTS and elongation were 563 ± 7 MPa and 10.0 ± 1.2 %, respectively, and negligible mechanical anisotropy of Al-Zn-Mg-Cu alloys was obtained. The good properties, which reached the wrought level, were attributed to the equiaxed grains and low porosity, as well as abundant strengthening phases. This work demonstrated the potential of additive manufacturing to fabricate alloys with unique microstructures and high performance for structural applications.
AB - The Al-Zn-Mg-Cu alloys fabricated by wire arc additive manufacturing (WAAM) have inferior performance due to poor microstructures and inevitable defects, which restrict their development. This study explored the hot-wire arc additive manufacturing (HWAAM) of the 7055 alloy, and proposed a three-stage solution and aging heat treatment method to further improve its mechanical properties. Both as-deposited and heat treated samples were mainly composed of equiaxed grains. Within grains of the as-deposited sample, the Mg(Zn,Cu)2 were precipitated. After heat treatment, apart from the small and abundant Mg(Zn,Cu)2 precipitates, the Al3Zr were also precipitated. Crack-free 7055 alloy parts were obtained, and the low porosity of as-deposited and heat treated samples were 0.18 % and 0.26 %, respectively. In addition, the alternating clustered-pore zones and discrete-pore zones were observed in both samples. After heat treatment, UTS and elongation were 563 ± 7 MPa and 10.0 ± 1.2 %, respectively, and negligible mechanical anisotropy of Al-Zn-Mg-Cu alloys was obtained. The good properties, which reached the wrought level, were attributed to the equiaxed grains and low porosity, as well as abundant strengthening phases. This work demonstrated the potential of additive manufacturing to fabricate alloys with unique microstructures and high performance for structural applications.
KW - Al-Zn-Mg-Cu alloys
KW - Grain morphologies
KW - Hot-wire arc additive manufacturing
KW - Mechanical properties
KW - Pores
KW - Strengthening precipitates
UR - http://www.scopus.com/inward/record.url?scp=85135684371&partnerID=8YFLogxK
U2 - 10.1016/j.addma.2022.103042
DO - 10.1016/j.addma.2022.103042
M3 - Article
AN - SCOPUS:85135684371
SN - 2214-8604
VL - 58
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 103042
ER -