Abstract:The hot deformation behavior of a spray formed Al−22Si−5Fe−3Cu−1Mg alloy was investigated by isothermal compression tests at temperature ranging from 350 °C to 500 °C and strain rate from 0.001 s⁻¹ to 0.1 s⁻¹. At the beginning of deformation, work hardening is the major factor. The flow stress quickly reaches a peak, followed by a continuous reduction, then a balance is established between the tendency to work harden and the tendency to flow soften. The stress curves appear almost in flat shape. A constitutive equation in the hyperbolic sine function for describing the deformation behavior was established and the hot deformation activation energy was determined to be 312.65 kJ/mol. It can be concluded that the temperature of extrusion should not be more than 500 °C in order to avoid primary silicon coarsen.

Key words: spray forming; Al−Si alloy; hot deformation behavior; constitutive equation