Laser melting deposition of aluminium 7050 alloy: heat treatment, microstructure and mechanical properties

ABSTRACT

In this study, the microstructure and mechanical properties of laser melting deposited 7050 aluminium alloy are investigated. An anisotropic microstructure is observed in the alloy: the columnar-grained structure on the building plane and a fine equiaxial structure on the scanning plane. Pores are the main metallurgical defects found but a higher energy input can significantly reduce large pores. The mechanical properties can be significantly improved with heat treatment. After being subjected to multiple solution and aging treatments, the hardness, ultimate tensile strength and elongation at break of the printed alloy increase by 58.6%, 14.06% and 27.8%, respectively. This research offers a reference for the formation technique of large and complex 7xxx series aluminium alloy parts by additive manufacturing.

KEYWORDS:

• Laser melting deposition
• 7050 aluminium alloy
• microstructure
• mechanical properties
• aluminium alloy
• metallurgical defects
• pore defects
• heat treatment

Disclosure statement

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

Additional information

Funding

This work was financially supported by the Jiangxi Provincial Natural Science Foundation [grant number 20202BABL214026] and Ganzhou Science and Technology Planning Project [grant number Ganshikefa[2019]60].