Influence of Rib Length on the Solidification of Cast Parts

Résumé

The ribs applied to the walls of cast parts are designed for enhancing both stiffness and aesthetics. The presence of ribs modifies the conditions of heat transmission and implicitly the solidification of the alloy in the joining area of the rib to the part wall. This is highlighted by the modified radius of the circles inscribed in the rib – wall joining area. The diameter of the circles inscribed in this area is greater than of those in the rest of the part wall. This leads to the assumption that the solidification of the alloy in this area is slowed. The paper presents the results of a study concerning the influence of rib dimensions (length) on the duration of cast part solidification and on the position of the hot spots. The study was conducted by computer simulation of solidification. The results have revealed that in certain situations (thin ribs compared to wall thickness) the ribs cause an acceleration of the solidification of cast parts. The length of thin ribs ensuring the maximum cooling effect is determined.