Modeling of transverse welds formation during liquid–solid extrusion directly following vacuum infiltration of magnesium matrix composite

Abstract

Liquid–solid extrusion directly following vacuum infiltration (LSEVI) is an infiltration–extrusion integrated forming technique, and transverse weld between upper residual magnesium alloy and magnesium matrix composites is a common internal defect, which can severely reduce the yield of composite products. To improve current understanding on the mechanism of transverse welding phenomenon, a thermo-mechanical numerical model of LSEVI for magnesium matrix composites was developed. The formation of transverse weld during extrusion was visualized using finite element simulation method, and the formation mechanism was discussed from the aspect of velocity field using a point tracking technique. The simulation results were verified by the experimental results in term of weld shape.

Keywords

• Liquid–solid extrusion
• Magnesium matrix composite
• Transverse weld
• Finite element simulation