The overburning temperature of the ZL205A (Al–5Cu–0·4Mn) alloy is first determined by differential scanning calorimetry analysis. Then, the solid solution temperature of ZL205A was determined by metallurgical microstructure observation. Isothermal compression tests of the as quenched ZL205A were conducted in temperature from 25 to 500°C and the strain rate from 0·001 to 1 s−1. The deformation behaviour of the as quenched ZL205A was investigated. The prediction of the flow stresses were studied using artificial neural network. The average absolute relative error between the predicted flow stresses and experimental results is 4·4, which demonstrates that the network proposed in the present paper has high precision. Therefore, it can be chosen as a thermomechanical model to treat the distortion problems of components during quenching process.