Avaliação das deformações em moldes de injeção de alumínio

Abstract

Simulation of the high pressure die casting process is already part of the design flow in die shops. Structural analysis of the die casting die, however, is less common. Knowledge of the loads applied on the mold and their effects on the deformation of the components is important for the safety of the operation, the quality of the part produced and possible material savings. However, in order to remain competitive with other shops, the structural analysis method must be accurate, fast and easy to use. With this requirement in mind, in order to increase understanding of the deformations suffered by a die casting die during the cycle, three study methods were selected to be evaluated. The Finite Element Method, the External Approximations by Finite Element Method and the Analytical Method. These three methods were used to calculate the deformations suffered by the structural components of a small die. Two sets of experiments were carried out. In Stage 1, dies were simulated under purely mechanical, purely thermal and combined loading, in order to understand the contribution of each type of loading to the deformation of the components. By comparing the results using the three load cases, it was found that thermal loads had the greatest effect on the fixed side of the mold, while mechanical loads were the main source of deformation on the moving side. In Stage 2, modifications to the bottom thicknesses of the structural components were applied to the original model in order to understand the effect of these dimensions on the die's deformations. As a result, it was found that the components on the moving side are more sensitive to changes in the bottom thickness of their components than those on the fixed side, showing increases in deformation of up to 118% in the moving side, while the fixed side had no more than 31%. Finally, comparing the three methods in the two stages? experiments, it was concluded that the analytical method lacks precision, has consistently lower deformations than the other methods, and is not very sensitive to the dimensional changes of Stage 2. The External Approximations by Finite Element Method shows potential for implementation in tool shops, with accurate results in comparison with those obtained by FEM, ease of use and solving speed. [resumo fornecido pelo autor]