Production of Al/Mg-Li composite by the accumulative roll bonding process

Abstract

Although Mg-Li alloys have been recognized as super-light structural alloys which have considerable ductility, weak strength and low corrosion resistance have limited their applications. To achieve proper strength and formability simultaneously, for the first time, dual-phase magnesium-lithium alloy is used to fabricate AA1050/MgLZ91 composite. Also, in this paper, for the first time, Mg-Li alloy has been utilized to fabricate three layered laminated sheets in various strain rate. The ARB process is utilized to produce laminated composite specimens at ambient temperature in four separate cycles and microstructure and mechanical properties evaluation are accomplished for all samples. Results showed that despite the process performed at ambient temperature, the adhesion quality of the layers was very high, and the magnesium-lithium layers were completely continuous in the aluminum matrix. The main reason was the high ductility of this alloy and its flow properties close to aluminum at ambient temperature. By applying high strain, the mechanical properties, including strength and microhardness of both layers, were greatly enhanced. In the fourth pass, the UTS value reached 225.8 MPa that soared by 276% and 84%, compared to the Al and LZ91, respectively. Compared with other Al/Mg composites, more than three times, the ductility was obtained. Much of the modification were the result of the work hardening and fine-graining mechanism, of course, the extraordinary ductility of the magnesium-lithium alloy at ambient temperature.

Keywords

• Mg-Li alloy
• ARB
• Formability
• Al/Mg composite
• Mechanical properties and microstructure