National Aeronautics and Space Administration


Date of this Version



Oxidation of Metals, Vol. 57, Nos. 5/6, June 2002


U.S. Government Work


COSP is a publicly available computer Program that models the Cyclic Oxidation weight gain and Spallation process. Inputs to the model include the selection of an oxidation-growth law and a spalling geometry, plus oxide phase, growth rate, spall constant, and cycle-duration parameters. Output includes weight change, the amounts of retained and spalled oxide, the total oxygen and metal consumed, and the terminal rates of weight loss and metal consumption. The present version is an updated Windows-based program, allowing greater compatibility with current PC operating systems. Viewing of multiple models and model fits to experimental data are enabled by an instant plotting feature and iterative modifications. Families of model curves are presented, which readily show the sensitivity to all the input parameters as well as the behavior of different growth laws and spalling modes. The cyclic behavior of NiAl and a complex superalloy are shown to be properly fitted by model curves. However, caution is always advised regarding the uniqueness claimed for any specific set of input parameters.