OPTIMIZATION OF QUENCH HISTORY OF ALUMINUM PARTS FOR SUPERIOR MECHANICAL-PROPERTIES

Cooling of an age-hardenable aluminum alloy after the high temperature forming process influences the metallurgical structure and, hence, th e mechanical properties of the part. An intelligent spray quenching sy stem is proposed which selects the optimal spray nozzle configuration based on part geometry and composition such that the quenched part att ains superior mechanical properties. The present study demonstrates a method for maximizing the magnitude and uniformity of hardness (and yi eld strength) and qualitatively minimizing residual stresses within th e quenched part by manipulation of spray intensity and hydrodynamic ch aracteristics. Furthermore, the quenching of a complex-shaped alloy wi th multiple, partially overlapping sprays was successfully modeled usi ng spray heat transfer correlations as boundary conditions within a fi nite element program. The results of this study facilitate the eventua l incorporation of optimization techniques such that the nozzle config uration for a given part can be selected prior to quenching, thus achi eving superior part quality with minimal costs.