In die-quench forging of heat-treatable aluminum alloys, a billet is held at high temperature for solution treatment, then compressed and rapidly cooled simultaneously between cold dies to form supersaturated solution. This process is similar to hot stamping of aluminum alloy sheets, however a workpiece billet is relatively thicker and thickness strain is larger. Although many applications of slide motion control on a servo press were proposed, it has not been well discussed as a method to control microstructure and properties of the workpiece. In die-quench forging of AA6061 billet, effect of die speed is discussed to achieve higher hardness with uniform distribution. (C) 2016 CIRP.