Interfacial characteristics of Zn/AZ31/Zn clad sheets fabricated by hot roll-bonding and annealing

ABSTRACT

The Zn/AZ31/Zn tri-layer clad sheets are prepared by hot roll-bonding technology and post-roll annealing in this study and the interfacial microstructure, mechanical and corrosion properties are investigated. The annealing temperature can influence the interfacial bonding behaviour. Upon annealing at 200°C, a good metallurgical bonding interface composed of Mg₄Zn₇ and MgZn₂ phases is obtained. A higher temperature (300°C) can induce the precipitation of the brittle Mg₂Zn₁₁ phase at the interface. The clad sheets annealed at 200°C can attain the maximum bonding strength among all the clad sheets investigated. Importantly, the corrosion rate can be obviously reduced by cladding pure Zn layer on both sides of AZ31 alloys, which provides another effective method to improve the corrosion resistance of magnesium alloys.

KEYWORDS:

• Zn/Mg/Zn tri-layer clad sheets
• hot roll-bonding
• post-roll annealing
• interfacial microstructure
• mechanical and corrosion properties

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Jian Wang http://orcid.org/0000-0002-9644-9923

Additional information

Funding

This research was supported by the National Natural Science Foundation of China [51671017], Fundamental Research Funds for the Central Universities, University of Science and Technology Beijing, China [No. FRF-GF-17-B3], and the fund of the State Key Laboratory of Solidification Processing in NWPU [SKLSP201835].