Computational Modeling of D. C. Casting of Aluminum Alloy Using Finite Element Method

摘要

A pertinent simulation model of transient D. C. casting of aluminum is developed and implemented in a general purpose finite element code ABAQUS to determine the time dependent temperature field and thermal stress field in the ingot during casting. The objective of this investigation is to find the temperature gradient and associated thermal stresses which may be the cause of the ingot cracking during casting. In this transient analysis, fully coupled temperature and displacement elements are used and latent heat of the alloy is also included. In order to simulate the water cooling process, a novel heat flow model is developed based on the measured temperature data. The bottom block is also modeled including heat transfer through the interface between the ingot and bottom block. Regions of high temperature gradient and peak stresses are analyzed. From the numerical simulation, mechanism of the cracking occurrence during D. C. casting is analyzed. The predicted locations of the maximum stresses coincide with the observed crack initiation sites and crack propagation paths. The butt curl displacement of the ingot is also predicted and agrees with production result.