Effect of water-based lubrication on friction behaviour of 7075 aluminium alloy sheet in hot stamping

DOI

10.2991/978-94-6463-581-2_46How to use a DOI?

Keywords

7075 aluminum alloy; Hot stamping; Water-based lubricants; Friction behavior

Abstract

Hot stamping technology is an effective way to achieve lightweight vehicles using aluminum alloy. Aluminum alloy is increasingly used in automobile manufacturing due to its high specific strength and recyclability. However, severe high-temperature friction and wear during the hot stamping forming process can scratch the surface of the formed parts, limiting its further promotion. Although solid lubricants, such as graphite, can improve friction, the ‘double carbon’ target proposed in recent years has raised the bar for the environmental friendliness of the production process. Furthermore, the experimental device and method are the core of tribology research in hot stamping. This article aims to study the friction behavior of 7075 aluminum alloy under water-based lubricant conditions using a self-designed vertical friction tester that overcomes gravity bending. we designed and developed an independent vertical friction experimental machine. By changing the loading method of the plate, the machine greatly improves its bending resistance and ensures accurate experimental results. By using the friction tester, the effect of process parameters on the lubrication behavior of water-based lubricants was investigated and compared it with commercial BN lubricants. The results showed that temperature and speed parameters had the most significant impact on the lubrication behavior. At 300℃ and 350℃, the coefficient of friction remains low throughout the sliding process due to the intact lubrication film. The dominant form of friction is abrasive friction. However, at 400℃, the lubrication film detachment increases, leading to the emergence of viscous friction. Furthermore, as the sliding speed increases, the shedding and transferring of the lubricant film decreases noticeably, resulting in a consistently smoother coefficient of friction at a speed of 100 mm/s. It is also worth noting that the coefficient of friction is lower at a sliding speed of 100 mm/s. Finally, the cumulative frictional wear behavior of 7075 aluminum alloy under lubrication conditions was investigated. The friction coefficient increased significantly with continued sliding distance, and the appearance of stickies was found to be the main cause of plate scratches. Two main modes of lubrication for water-based lubricants are the transfer of the lubricating film on the surface of the friction pair during sliding and the filling of the peaks and valleys of the stickies by the lubricating film.

Copyright

© 2024 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

Download article (PDF)

TY  - CONF
AU  - Yilin Wang
AU  - Yunpeng Wang
AU  - Dongyu Fang
AU  - Yisheng Zhang
PY  - 2024
DA  - 2024/12/07
TI  - Effect of water-based lubrication on friction behaviour of 7075 aluminium alloy sheet in hot stamping
BT  - Proceedings of the 7th International Conference on Advanced High Strength Steel and Press Hardening (ICHSU 2024)
PB  - Atlantis Press
SP  - 373
EP  - 381
SN  - 2590-3217
UR  - https://doi.org/10.2991/978-94-6463-581-2_46
DO  - 10.2991/978-94-6463-581-2_46
ID  - Wang2024
ER  -