A novel forming process of Al / Mg composite circular tube based on experiments and numerical simulations

Abstract

Abstract In this paper, a method of co-extrusion bimetallic combining direct extrusion and expanding shear deformation ( DEES ) process is described. This method was used to prepare Al / Mg bimetallic tubes. The composite tubes were successfully prepared at 360 ℃, 390 ℃, 420 ℃ and 3mm / s. a mathematical model of co-extrusion process using DEFORM-3D was developed to deeply understand and scientifically recognize the material flow and metallurgical reaction between aluminum alloy and magnesium alloy during co-extrusion. The finite element analysis results show that the influence of extrusion temperature on the bonding properties of extruded bimetals is reflected in many aspects due to the difference of material properties, such as atomic diffusion energy and flow stress difference during extrusion. To further analyze the deformation mechanism of Al/Mg bimetal tube in the deformation process, the microstructure of the interface bonding layer at different forming temperatures was observed and analyzed. In addition, the hardness test results show that reasonable control of the deformation temperature can improve the performance of the matrix material while reducing the thickness of the bonding layer.