Modification of residual stress and microstructure in aluminium alloy by cryogenic treatment

Abstract

The effect of cryogenic treatment (CT) combined with solution and ageing treatment on the residual stress and microstructure of 7050 aluminium alloy was investigated. The relationship between residual stress and microstructure was discussed. The results showed that compared to solution–ageing treatment (SA), CT after solution and before ageing (SCA) exhibited lower level and higher uniformity of residual stress. The highest dimensional stability was also obtained by the process of SCA. It was found that CT induced the fine precipitates through the lattice contraction under cryogenic temperature. Furthermore, the execution of CT in advance would also promote the uniform distribution of precipitates in the subsequent ageing by releasing and homogenising the residual stress.

KEYWORDS:

• Cryogenic treatment
• aluminium alloy
• residual stress
• dimensional stability
• microstructure
• precipitation
• mechanical properties

Acknowledgements

This work was supported by the [National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809] under Grant [number 51805521]; the director fund of Technical Institute of Physics and Chemistry, CAS; and the [Youth Innovation Promotion Association of 10.13039/501100004739 CAS] under Grant [number 2016021].

Disclosure statement

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

Additional information

Funding

This work was supported by the [National Natural Science Foundation of China] under Grant [number 51805521]; the director fund of Technical Institute of Physics and Chemistry, CAS; and the [Youth Innovation Promotion Association of CAS] under Grant [number 2016021].