Dr. Jesper Thorborg, Jörg Zimmermann und Dr. Corinna Thomser, Aachen
Sand casting of metal parts is one of the most flexible manufacturing processes for differently shaped and sized castings. The process is applicable for a wide range of alloys and the obtained material quality and dimensional tolerances can be controlled by modifying either the design of the part or the casting layout. The flexibility in design provided by the shaping sand material and the internal sand cores often leads to a complex cooling history, which highly affects the evolution of properties and defects. Many defects in the final part like e. g. cold cracks and hot tears are related to the stresses that build up during cooling. This article presents how MAGMASOFT® is used to analyze and optimize both the casting design and the casting process by combining the thermal analysis of the casting process with an integrated prediction of stress and distortion. It is shown how the thermal gradients, cooling time and constraints from the mold and core materials affect the risk of stress related defects and unwanted distortion. Methodological application on industrial examples show the significant advantages of being able to systematically analyze different designs and casting layouts upfront, to avoid quality problems in production and fulfill dimensional tolerance requirements.
Stresses in sand casting – analysis and optimized solutions for improved casting designs and product quality