Investigations of deformation of FGM

FGM are marked by a heterogeneous composition changing continuously. Theref ore, it must be considered while deformation that different material ranges show different deformation behaviour and that the overall deformation is i nhomogeneous. For this reason the graded material was subdivided into a fin ite number of ranges for the simulation of the deformation behaviour. Homog eneous material behaviour is assumed in these ranges. The yield strengths o f the respective homogeneous materials are determined experimentally and th en applied as material parameters in the simulation. A simple upsetting of a cylindrical specimen at constant temperature and deformation rate was cal culated as an example. The results of the simulation show that, as expected , the material flow is marked differently in various material ranges due to the differing yield strength. This is confirmed by experimental investigat ions. Differences in the results of simulation and experiments in particula r occur in the case of the direct comparison of the geometrical dimensions. This is mainly explained by differing initial microstructures. The compari son of the compression forces shows good agreement between simulation and e xperiment. (C) 2000 Elsevier Science B.V. All rights reserved.