By understanding the effects of flask quenching on various precious and base metal formulations, one can properly diagnose and understand appropriate techniques to overcome cracking defects and harden or soften the metal, depending on the process requirement. This paper will discuss the actual testing data on Vickers hardness, flexure strength and bend-test values of various precious metal alloys (karat gold, sterling silver, platinum, and palladium) and brass/bronze alloys, based on early and late quenching of the flask. Special quenching techniques to overcome cracking of diamonds in 18K pink-gold, stone-in-place castings will also be discussed. Scientific test data will include actual test specimens cast and quenched in water at different times. A scientific/metallurgical explanation of the factors responsible for these effects will also be presented. Flexure and bend-testing data is in accordance with ASME specifications.

Author: Ajit Menon