Computer simulation of investment casting has recently been identified as a powerful tool for giving new insight into defect generation mechanisms, especially those related to form filling, shrinkage porosity and gas porosity caused by reaction with investment material. While previous work of the author's group mainly focused on simulation of silver investment casting, the overall aim of still ongoing work is the further development of the simulation tool for gold alloys. This paper is a status report on the advances obtained so far in understanding different thermal properties of some 18K gold casting alloys, and how these properties influence solidification and susceptibility to porosity. Furthermore, the impact of thermal properties of investment material, as well as the potential role of different types of simulation software, is briefly discussed. The potential of simulation tools assisting in prevention and control of investment casting defects is indicated.

Author: Dr. Jörg Fischer-Bühner