Constitutive equations of 1060 pure aluminum based on modified double multiple nonlinear regression model
(State Key Laboratory of Solidification Processing, School of Materials Science and Engineering,
Northwestern Polytechnical University, Xi’an 710072, China)
Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: In order to study the work-ability and establish the optimum hot formation processing parameters for industrial 1060 pure aluminum, the compressive deformation behavior of pure aluminum was investigated at temperatures of 523-823 K and strain rates of 0.005-10 s-1 on a Gleeble-1500 thermo-simulation machine. The influence rule of processing parameters (strain, strain rate and temperature) on flow stress of pure aluminum was investigated. Nine analysis factors consisting of material parameters and according weights were optimized. Then, the constitutive equations of multilevel series rules, multilevel parallel rules and multilevel series & parallel rules were established. The correlation coefficients (R) are 0.992, 0.988 and 0.990, respectively, and the average absolute relative errors (AAREs) are 6.77%, 8.70% and 7.63%, respectively, which proves that the constitutive equations of multilevel series rules can predict the flow stress of pure aluminum with good correlation and precision.
Key words: 1060 pure aluminum; modified DMNR (double multiple nonlinear regression) constitutive equation; flow behaviour; multilevel series rules, multilevel parallel rules; multilevel series & parallel rules