The effect of coatings on the thermo-mechanical response of cylindrical specimens during quenching

This paper investigates, experimentally and numerically, the effect of various surface treatments on the thermo-mechanical response of aluminum cylindrical missiles during warm water quenching. The surface coating treatments include specialized solutions of aluminum oxide, aluminum silicate hydroxide, and phosphate wetting agents, among others. It is shown that these surface treatments can have a strong impact on the wettability of the aluminum surface, the promotion of nucleate boiling and the magnitude of the residual stresses in the metal after quench. Temperature histories recorded during quench allowed surface heat-transfer coefficients to be computed using an inverse heat-transfer code, and the thermal data was later used in a FE code to predict the mechanical deformation and the residual stress state after quench. Comparisons of experimental data with FE results are included for selected cases.