Numerical simulation and preparation of cladding billet by direct chill semi-continuous casting

Abstract

This study presents an innovative direct chill semi-continuous casting process to prepare AA4045/AA3003 cladding billet using numerical simulation and experiments. The influence of casting speed on temperature field in cladding billet has been investigated by the commercial software FLUENT and validated by experiments. The cladding billet was examined by methods of metallographic examination, field emission scanning electron microscopy (FESM) and universal testing machine. The results show that the experiments are in good agreement with the simulation results. Cladding billets can be obtained at the casting speeds ranging from 110mm/min to 150mm/min. Excellent metallurgical bonding of the two alloys could be achieved at the casting speed of 130mm/min and 150mm/min. With the increase of casting speed, increasing contact temperature promotes the interdiffusion of alloy elements. The tensile strength and shear strength of interface reaches 106 MPa and 77 MPa respectively. Moreover, fracture position moves to AA3003 side from the interface in tensile test, while fracture mode changes to the ductile from the brittle as casting speed increases.