Sc/Zr microalloying on strength-corrosion performance synergy of wire-arc directed energy deposited Al-Mg

ABSTRACT

WADED Al-Mg and Al-Mg-Sc-Zr aluminium alloy thin-wall components were produced. Heat treatment (350°C aging for 4 h) was further conducted. The effects of Sc/Zr addition on porosity, microstructure, mechanical properties and corrosion behaviour were investigated. With Sc/Zr adding, pore area fraction decreased from 0.208 to 0.005% and grain size decreased from 84.34 to 19.54 μm. In WADED Al-Mg-Sc-Zr component, microstructure showed refined equiaxed grains. Mechanical properties were improved with 360 MPa ultimate tensile strength (UTS), 185 MPa yield strength, and 23.31% elongation. After heat treatment, UTS increased to 388 MPa with good ductility (22.53%) maintained. The grain refinement and Al₃(Sc, Zr) particles were the key factors for mechanical property improvement. The corrosion behaviour was improved with introduced Sc/Zr and further optimised after heat treatment. The corrosion exhibited layered characteristics due to the distribution of primary Al₃(Sc, Zr) while minor-size secondary Al₃(Sc, Zr) along grain boundaries improved the corrosion behaviour.

KEYWORDS:

• Wire-arc directed energy deposition
• Al-Mg-Sc-Zr alloy
• heat treatment
• microstructure and mechanical properties
• corrosion behaviour

Disclosure statement

No potential conflict of interest was reported by the author(s).

CRediT authorship contribution statement

Yubin Zhou: Data curation, Formal analysis, Investigation, Methodology, Visualisation, Writing – original draft. Zewu Qi: Investigation, Methodology, Resources, Supervision, Writing – review & editing, Funding acquisition. Baoqiang Cong: Investigation, Resources, Supervision, Writing – review & editing. Zihao Jiang: Visualisation, Writing – review & editing. Xinyi Cai: Investigation, Writing – review & editing. Hongwei Li: Investigation, Writing – review & editing. Jiaqi Zhang: Investigation, Writing – review & editing. Chaofang Dong: Software, Writing – review & editing. Xing He: Software, Writing – review & editing. Sanbao Lin: Writing – review & editing. Xiaoyu Cai: Writing – review & editing. Bojin Qi: Investigation, Project administration, Resources, Writing – review & editing.

Data availability statement

Data will be available upon reasonable request.

Additional information

Funding

This work is supported by National Natural Science Foundation of China (grant numbers 52105315, 52075022 and U20B2031), State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology (AWJ-24M05), Natural Science Foundation of Beijing Municipality (grant numbers 3222013) and Fundamental Research Funds for the Central Universities (YWF-22-L-607).