EXPERIMENTAL AND NUMERICAL STUDY OF QUENCHING COMPLEX-SHAPED METALLICALLOYS WITH MULTIPLE, OVERLAPPING SPRAYS

The present study constitutes a crucial step towards the development o f a CAD based intelligent spray quenching system capable of optimizing the mechanical properties (strength, hardness) of age-hardenable alum inum alloys. The quenching of an L-shaped aluminum alloy with multiple , partially overlapping spray nozzles was successfully modeled using t he finite element method. Spray heat transfer correlations, which rela te the local heat transfer rate in each of the boiling regimes experie nced by the surface to the local values of the spray hydrodynamic para meters (volumetric spray flux, mean drop diameter, mean drop velocity) , were used as boundary conditions. The spatial distributions of the s pray hydrodynamic parameters were modeled and incorporated into the fi nite element program. Axial nonuniformity in the heal transfer coeffic ient along the surfaces of long extrusions, which can lead to unwanted residual stresses, was eliminated by developing a method for optimizi ng the distance between adjacent nozzles. The numerical results were e xperimentally verified in a simulated industrial environment. This stu dy is the first successful attempt at systematically predicting the te mperature response of a quenched part from knowledge of only the part geometry and spray nozzle configuration. Integration of the finite ele ment program with an optimization routine will yield a system capable of selecting the appropriate spray nozzle configuration for a new part prior to production; thus, achieving superior part quality without co nducting costly experimental tests.