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Investigation on strengthening of 7075 aluminum alloy sheet in a new hot stamping process with pre-cooling

  • Lijuan Zhu
  • Zhaoxiang Liu
  • Zhiqiang ZhangEmail author
ORIGINAL ARTICLE

Abstract

Hot stamping (HS) process is a new technology for fabricating high-strength aluminum alloy. In order to improve the formability of materials in the forming process, a new hot stamping process with pre-cooling (HSPC) is proposed in this paper. By adding a pre-cooling stage between the solid solution and the forming, the strain hardening exponent (SHE) could be increased due to the decreasing of the forming temperature, and the uniform deformation ability could be improved. In the HSPC of 7075 aluminum alloy, the blanks exhibited two pre-cooling modes: air cooling pre-cooling (ACPC) and cold iron pre-cooling (CIPC). The effects of pre-cooling rate and temperature on the microstructure and mechanical properties of formed parts were studied. The results showed that when the pre-cooling temperature was 300 °C by CIPC, the formed parts had the smallest thickness thinning and the best mechanical properties after aging. Compared with ACPC, CIPC had less precipitation during quenching, which ensured good subsequent aging strengthening effect.

Keywords

Aluminum alloy Hot stamping Pre-cooling Precipitation 

Notes

Funding information

This work was supported by “13th five-year” Scientific Research Planning Project of the Education Department of Jilin Province, China (JJKH20180128KJ).

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Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2019

Authors and Affiliations

  1. 1.Key Laboratory of Automobile Materials, School of Material Science and EngineeringJilin UniversityChangchunChina

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