Microstructure Evolution of 5052 Aluminum Sheet in Electromagnetic High-Speed Impact

Fei Feng,Liang Huang,Jianjun Li,Yunjun Zhang,Rongchuang Chen,Guangbao Shao,Shijing Cao,Hongliang Su

doi:10.3390/met10050564

Abstract

Electromagnetic forming (EMF) is a high-speed forming technology, which can not only improve the formability of hard-to-form materials but also reduce springback. Electromagnetic high-speed impact can further improve the formability compared with electromagnetic free forming. The microscopic deformation mechanism of electromagnetic high-speed impact of aluminum alloy is discussed in this paper. The microstructures of electromagnetic high-speed impact of an aluminum alloy sheet were characterized. The microscopic deformation mechanisms of electromagnetic forming and electromagnetic high-speed impact were shown, respectively. The research results showed that electromagnetic high-speed impact could significantly improve the microhardness of the workpiece. The grains broke up and then became small subgrains during electromagnetic high-speed impact. The deformation mechanism was dominated by dislocation cross slip under electromagnetic high-speed impact.

Highlights

Aluminum alloy sheets are widely used in vehicles and airplanes because of the advantage of fuel economy and reduced environmental pollution [1,2]
The high-speed impact forming is shown in Figure 6, and the micro hardness values are shown in Table plastic deformation amount of region
The grains broke into small subgrains when the center of the sheet impacted to the conical die under inertial action, and a large number of small grains were formed during electromagnetic high-speed impact

Summary

Introduction

Aluminum alloy sheets are widely used in vehicles and airplanes because of the advantage of fuel economy and reduced environmental pollution [1,2]. Electromagnetic forming (EMF), a high-speed forming technology, can improve formability and reduce springback [4,5]. The formability of aluminum alloy sheets in high speed forming had been studied by many researchers. The electromagnetic ring expansion process of AA6061-T4 and pure copper was investigated by Tamhane et al [6], and a doubled formability was reported, comparing it with the formability in quasi-static (QS) forming. By comparing the forming limits of Ti-6Al-4V and AA5052-O under QS and EMF, Li et al [7] observed a formability increase by 24.37% and 10.97%, respectively, in EMF. It was reported by Vohnout [8] that the formability of

Results

Discussion

Conclusion