Novel Direct Cladding of Magnesium and Aluminum Alloys Using a Horizontal Twin Roll Caster

Abstract

This study introduces the direct cladding of magnesium and aluminum alloys using a horizontal twin roll caster in one step. A horizontal twin roll caster can cast a Mg/Al clad strip with thickness exceeding 5mm at a roll speed of 8m/min in one step, which is difficult for a vertical twin roll caster. Therefore, it is possible to cast a thick clad strip with different melting point alloys using a horizontal twin roll caster at low speed. It is also possible to cast clad strips using as the overlay an alloy that has a higher melting point than that of the base strips. The thickness of the Mg/Al clad strip is 6.5mm, and the ratio of the Mg layer to the Al layer is 3:2. The surface of the clad strip is good, and there is no void between bonding interfaces. The mixing layer of the bonding interface is deeply related to the reduction rate. As the reduction rate increases, the mixing layer becomes more balanced and the thickness of the mixed layer decreases to 68μm. By observation of the interface of the cladded material, the mixed layer of the bonding interface is divided into two layers. It has been found the mixed layer near the Al layer has the highest hardness (up to 228HV), and the tensile shearing strength of the manufactured Mg/Al clad strip was 44MPa.