Equipment and procedures were used in a development project to determine temperatures of 14K yellow gold inside mold cavities in an investment casting flask during mold filling and the early stages of freezing. Items that will be presented include test equipment requirements and specifications, special wax ring patterns, techniques to eliminate electronic interference, and the handling of large volumes of data. Some of the more significant topics include metal velocity in pouring streams and individual mold cavities. From the data acquired, the metal stream velocities were calculated and compared, including the velocities in individual mold cavities during a fill cycle. This study revealed the temperature/time sequence of the ring cavity during filling. High-speed temperature data collection was used to record differences in the metal temperatures during flow and solidification in the mold cavities showing temperature gradients. Local solidification times and cooling rates based on liquidus and solidus temperatures of 14K yellow gold alloy were also measured.

Author: Patrick DuBois, Dr. Shankar Aithal, John C. McCloskey