Prediction and Prevention of Distortion for the Thin-Walled Aluminum Investment Casting

Abstract

Investment casting is one of main precision casting processes to realize near net shape castings. For the castings with thin-walled cross section or complicated shape, it is easy to generate casting stress such as thermal stress, mechanical stress and phase transformation stress, resulting in casting deformation due to the uneven cooling and hindered contraction. Once three-dimensional deformation is formed, it is very hard to correct. In this paper the finite element method (FEM) was used to analyze the stress and deformation of thin-walled lost wax casting. The results show that the temperature and stress distributions are uneven in the casting and the tendency to deform is higher even with insulating shell mold. And based on the results, the technical measures of adding supporting ribs are adopted to restrain deformation. The practice of volume production indicates that no casting was rejected due to deformation defects.