Fe/Mg/Fe Multilayer Composite Sheet Fabricated by Roll Cladding

Area of Science:

• Materials Science
• Metallurgy
• Surface Engineering

Background:

• Magnesium (Mg) alloys offer lightweight advantages but require surface hardening for broader applications.
• Galvanized steel provides corrosion resistance but achieving strong metallurgical bonds with Mg alloys is challenging.

Purpose of the Study:

• To fabricate a novel multilayer Fe/Mg/Fe composite sheet.
• To investigate the effect of roll cladding on the Mg surface hardness and interfacial bonding.
• To analyze the microstructure of the Mg/steel interface and the role of zinc.

Main Methods:

• Fabrication of Fe/Mg/Fe multilayer composite sheets using roll cladding of galvanized steel and Mg alloy sheets.
• Microstructural analysis of the Mg/steel interface using electron microscopy and phase identification.
• Measurement of Mg surface hardness before and after cladding.

Main Results:

• The roll-cladded composite sheet exhibited significantly improved Mg surface hardness, increasing from HV 65 to HV 132.
• Metallurgical bonding was achieved and improved with reduction ratios exceeding 10%.
• A 5-10 μm thick transition layer composed of zinc and a Mg-Zn intermetallic compound (0.97Mg-0.03Zn) formed at the Mg/steel interface.

Conclusions:

• Roll cladding is an effective method for producing Fe/Mg/Fe multilayer composites with enhanced Mg surface hardness.
• The zinc coating on galvanized steel plays a crucial role in promoting metallurgical bonding by forming beneficial intermetallic phases at the interface.
• The developed composite material shows potential for applications requiring lightweight components with improved surface durability.