Shell cracking is a never ending battle that Precision Investment Casting (PIC) foundries fight. Shell cracking in dewax requires repair and introduces opportunities for reduced quality of the casting. A shell crack can create a dangerous situation during casting, and lead to lower casting yields. There are many factors, both process and material related, that can contribute to shell cracking. This paper will introduce a method for measuring the crack potential of a shell, and continue the work presented last year where a new look at green shell permeability was introduced as a meaningful shell characterization tool. With a repeatable shell cracking model developed, a shell's properties can be correlated to shell dewax performance. With a better understanding of the parameters that are critical to resisting shell cracking, the materials and process can be modified as required to reduce shell cracking. By reducing shell cracking; quality, efficiency and safety can be improved.
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