Bonding and microstructure evolution in electromagnetic pulse welding of hardenable Al alloys

DOI: 10.1016/j.jmatprotec.2020.116965

Authors: Z. Li (Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University London) , E. Beslin (Constellium University Technology Centre, Brunel University London) , A.j. Den Bakker (Constellium University Technology Centre, Brunel University London) , G. Scamans (Brunel Centre for Advanced Solidification Technology (BCAST); Innoval Technology Ltd) , M. Danaie (Diamond Light Source) , C. A. Williams (Innoval Technology Ltd) , H. Assadi (Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University London)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Journal Of Materials Processing Technology

State: Published (Approved)
Published: November 2020
Diamond Proposal Number(s): 19064

Abstract: Electromagnetic pulse welding (EMPW) is a promising solid-state joining process, offering fast and strong bonding with no heat affected zone. Despite the growing interest in this process, there is little understanding of the dynamic phenomena that lead to bonding and microstructural changes during EMPW of key engineering materials such as age-hardenable aluminium alloys. This study combines experiments with numerical modelling of plastic deformation to provide an insight to these phenomena in joining of a high-strength aluminium alloy in the T4 and T6 temper conditions. Initially, bonding criteria are postulated in view of the calculated plastic strain at the interface of the T4 sample. These criteria are then used for the prediction of the extent of bonded interfaces for different sets of materials and process parameters. The predictions are shown to be in quantitative agreement with the experimental results for the T6 sample. The corresponding microstructural studies show that bonding is associated with remarkable microstructural changes in the samples, including dissolution of precipitates, formation of high-angle boundaries, and recrystallisation, especially near the bonded interfaces. Moreover, the results of post-weld heat treatments and mechanical testing demonstrate that the impact-induced deformation in EMPW can also influence subsequent precipitations, hence result in improved properties of the entire sample, in a way not achievable by conventional age hardening treatments.

Journal Keywords: Electromagnetic pulse welding; Bonding; Finite element analysis; Microstructure; Aluminium alloys

Diamond Keywords: Alloys; Welding

Subject Areas: Materials, Engineering

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E02-JEM ARM 300CF

Added On: 11/11/2020 10:17

Discipline Tags:

Materials Science Engineering & Technology Industrial Engineering Metallurgy

Technical Tags:

Imaging Tomography Cryo Electron Tomography (Cryo ET)