Numerical investigation of pull in control of rectangular AA1050 rolling ingot through the design of convex mould during direct chill casting process

Abstract

The pull in effect / concavity on the lateral faces of the ingot is formed during solidification of the ingot due to the thermal stresses induced in the ingot. A part of rolling ingots with pull in effect are cut by conventional cutting process which affects the recovery and increases wastage and cost of production. In the present work, an elemental death and birth technique was used to develop a numerical model to study mechanical and thermal behavior during solidification of AA1050 rolling ingot. The results of the model are validated with results of Williams model available in the literature. Furthermore, different mould designs provided with convexity on lateral surfaces with convexity radius of 16 mm to 26 mm were numerically analyzed. A series of numerical simulations were conducted with varying mould convexity with increment value of one. The results revealed that, providing convexity to the mould is an effective method to control the pull in effect during direct chill casting process. The convexity radius of 26 mm is enough to completely eliminate the pull in radius of 23.34 mm for the rectangular AA1050 ingot.