Effect of Quenching Wait Time on Microstructure and Mechanical Properties of As-Extruded AA6063 Alloy

Abstract

Effect of quenching wait time after hot extrusion on microstructure and mechanical properties of AA6063 alloy was investigated by optical microscopy observation, tensile and Brinell hardness tests. Results show that the quenching wait time has an important influence on the microstructure and mechanical properties of AA6063 alloy. During hot extrusion, dynamic recrystallization occurs only in local areas suffered much larger strains, however, only within 10s' wait time after extrusion, the static recrystallized grains have maturely developed. After subsequent T6 heat treatment, the recrystallized grains of the prompt-quenched sample are more uniform than that of the wait-quenched sample, and mechanical properties of the former are also better than that of the latter.