# Study on the Rolling Forming Process of Mg/Al Composite Foils with Low Edge Cracking

## TL;DR

Researchers developed a multi-step rolling process to create ultra-thin Mg/Al composite foils with minimal edge cracking, offering a practical method for industrial production.

## Contribution

A hybrid hot–cold rolling process with optimized parameters is introduced to reduce edge cracking in Mg/Al composite foils.

## Key findings

- A rolling temperature of 400 °C and a reduction ratio of 35% are optimal for superior Mg/Al interface bonding.
- A 21-pass process successfully reduced 0.5 mm Mg/Al plates to 30 μm with low edge cracking.
- Regulating temperature, reduction ratio, and annealing significantly controls edge cracking in composite foils.

## Abstract

What are the main findings?
A rolling temperature of 400 °C and a reduction ratio of 35% are the optimal simulated process parameters for achieving superior Mg/Al composite interface bondingThe initial 0.5 mm thick Mg/Al plates were successfully rolled down to 30 μm via a 21-pass process consisting of “hot rolling bonding + hot rolling + cold rolling and annealing”.This multi-stage rolling process can effectively inhibit the initiation and propagation of edge crackings in the composite foils.

A rolling temperature of 400 °C and a reduction ratio of 35% are the optimal simulated process parameters for achieving superior Mg/Al composite interface bonding

The initial 0.5 mm thick Mg/Al plates were successfully rolled down to 30 μm via a 21-pass process consisting of “hot rolling bonding + hot rolling + cold rolling and annealing”.

This multi-stage rolling process can effectively inhibit the initiation and propagation of edge crackings in the composite foils.

What are the implications of the main findings?
A feasible multi-pass rolling process scheme is provided for the preparation of ultra-thin Mg/Al composite foils with low edge cracking.It is revealed that the edge cracking issue of composite foils can be significantly controlled by regulating temperature, reduction ratio and annealing treatment.The research results offer important process references for the industrial-scale preparation of high-performance Mg/Al composite foils.

A feasible multi-pass rolling process scheme is provided for the preparation of ultra-thin Mg/Al composite foils with low edge cracking.

It is revealed that the edge cracking issue of composite foils can be significantly controlled by regulating temperature, reduction ratio and annealing treatment.

The research results offer important process references for the industrial-scale preparation of high-performance Mg/Al composite foils.

Edge cracking is prone to occur during the rolling of Mg/Al composite foils. Herein, a hybrid hot–cold rolling process was adopted to fabricate 30 μm thick Mg/Al composite foils with low edge cracking. AZ31B magnesium alloy and 5052 aluminum alloy sheets, both with an initial thickness of 0.5 mm, were chosen as research materials. Numerical simulations of composite pass were conducted at 300–450 °C with reduction ratios of 25–40%, and the optimal parameters were identified as 400 °C and a 35% reduction ratio. Based on this, multi-pass rolling experiments were performed: composite pass was heated at 400 °C for 10 min with 35% reduction ratio, hot rolling passes at 300 °C for 1–3 min, and subsequent cold rolling with 15% reduction ratio. After 21 rolling passes, 30 μm thick Mg/Al composite foils with low edge cracking were successfully prepared. Interface and metallographic characterizations demonstrated that the diffusion layer thickness varied slightly during hot rolling and increased moderately during cold rolling. For the magnesium alloy, hot rolling improved microstructural uniformity and reduced shear bands, while cold rolling caused decreased uniformity and the gradual emergence of shear bands. The research results provide a reference for the preparation of high-quality Mg/Al composite foils.