Flow Stress Characteristics and Constitutive Equation at High Temperature for 7050 Aluminum AlloyFU Xiu-li,AI Xing,WAN Yi,ZHANG Song(School of Mechanical Engineering,Shandong University,Jinan 250061,China)The flow stress behavior of 7050-T7451 aluminum alloy at the temperature range of 200—550 ℃ and the strain-rate range of 1 400—2 800 s~(-1) was investigated by means of high temperature split Hopkinson pressure bar(SHPB) test system. It was pointed out that the flow stress decreases with the increase of deforming temperature,while increased with the increasing of strain rate.Furthermore the flow stress level changed more dramatically with increasing temperature.The modified Johnson-Cook model could be widely used for description of flow stress and was selected as the constitutive model for 7050-T7451 aluminum alloy.At last a new set of material parameters of modified JC constitutive equation of this alloy was determined from experimental results.7050-T7451 aluminum alloy;flow stress; constitutive equation