Matematický popis deformačního odporu aluminidu železa Fe-40at.%Al za tepla

Abstract

In this work nonlinear regression was employed to calculating the material constants of the models proposed for mathematical description of hot flow stress of Fe-40at.%Al iron aluminide. Experimental values for the regression analysis were obtained by uniaxial compression tests on plastometer Gleeble in the temperature range 800 °C to 1200 °C and strain rate range 0.05 s-1 to 30 s-1. Obtained flow curves were smoothed by inverse method, due to the large dispersion of values. Using the ENERGY 4.0 the values of peak deformation were calculated. After that nonlinear regression analysis was carried out in the UNISTAT. At first, based on experience the model Schindler et al. was chosen. Then followed the model Hensel-Spittel used for computer simulation of hot deformation behavior in the FORGE. The predicted flow stresses by Schindler et al. model give a good agreement with experimental data. Even if prediction at high temperature and strain rate still hasn´t achieved entirely the accurate results. Prediction for the description of flow stress given aluminide according to the Hensel-Spittel model was found to be less appropriate. Nevertheless simulation of hot deformation behavior given aluminide in the FORGE could be realizable with sufficient accuracy.