Improved properties of wire arc directed energy deposited thin-walled Al-6Mg-0.3Sc component via laser shock peening

ABSTRACT

Heat treatment free aluminum alloys have been developed for wire arc directed energy deposition (DED) large thin-walled components, but their further performance enhancement methods remain unexplored. In this study, laser shock peening (LSP) treatment was performed on wire arc DED Al-6Mg-0.3Sc components. The results show that LSP creates a gradient microstructure with submicro-grains near the surface. The effects of LSP on defects were quantified by quasi-in-situ CT, demonstrating a reduction in porosity by over 68% together with decreased size. Simultaneously, tensile strength increases by 39.5% to 295.8 ± 6.4 MPa with only a marginal loss of elongation, as compared to the as-deposited (AD) state. This was due to the accumulation of dislocations and continuous dynamic recrystallization lead to grain refinement, as well as the appearance of a triple heterogeneous microstructure. Therefore, this study offers a novel solution for manufacturing of high-performance heat treatment free large thin-walled components.

KEYWORDS:

• Wire arc directed energy deposition
• heat treatment free
• laser shock peening
• grain refinement
• Al-6Mg-0.3Sc alloy

Acknowledgements

The authors acknowledge the finical support from the National Natural Science Foundation of China [Grant numbers 52205414, 52275374], as well as the fund of Young Elite Scientists Sponsorship Program by CAST [Grant number 2021QNRC001]. Special thanks are extended to Hang Guo and Yanan Chen from Instrumental Analysis Center of Xi’an Jiaotong University.

Disclosure statement

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

Data availability statement

Data will be made available on request.

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 52205414, 52275374]; Young Elite Scientists Sponsorship Program by CAST: [Grant Number 2021QNRC001].