Effects of Thermomechanical Treatment Process on the Microstructure and Properties of 7A04 Aluminum Alloy

Abstract:

The mechanical properties of a 7A04 aluminum alloy were improved by deformation strengthening and phase transformations strengthening adopting thermomechanical treatment, whose process include solution treatment, deformation treatment and ageing treatment in turn. The paper focuses on the influences of deforming degree and ageing process on microstructure and properties of 7A04 aluminum alloy. The experimental results show that hardness increased with increasing deformation ratio, and the value are greatly higher than that of samples after solution treatment. The results of ageing after deformation show that the hardness enhanced with prolonging the ageing time, which reach the peak value at 16 hours. In addition, the microstructure became more homogeneous and the grain was refined obviously by metallography microscope observation. The second phase precipitate dispersedly to strengthen the alloy. Above all, in order to obtain the better mechanical properties, the optimal thermomechanical treatment processes are solution treatment at 470°C for 2h, deformation with ratio of 40% as well as ageing at 120°C for 16h.

• Periodical: Advanced Materials Research (Volumes 335-336)
• Pages: 805-808
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.335-336.805
• Online since: September 2011
• Authors: Shi Xing Zhang, Hai Hong Wu, Gang Yi Cai
• Keywords: 7A04 Aluminium Alloy, Microstructure, Thermomechanical Treatment (TMT)

References

[1] Ning Ailin, Zeng Sumin, Jiang Shousheng: Light Alloy Fabrication Technology, 2005,5:48

[2] Peng Beishan, Ning Ailin, Jiang Shousheng: Hot Working Technology,2006, 18: 72-76

[3] Sanders RE,JR: Metall.Thermomechanicaltrans,1978,9:1087-1100.

[4] Wert J A．Paton N E: Metall Ttans,1981,12:267.

[5] Zheng Qingchun, Liu Zhiyi: Mining: Metallurgical Engineering, 2005, 4:69-73

[6] Huang Debin: Nonferrous Metal Material Manul, Machinery Industry Publishing China (2004) in Chinese