A MICRO MECHANICAL BASED CONSTITUTIVE MODEL FOR FINITE-ELEMENT SIMULATION OF HOT ISOSTATIC PRESSING OF POWDER

Hot isostatic pressing (HIP) facilitates new designs and product shapi ng, for example by direct manufacture of composite products with diffe ring materials in the various parts (compound). The specific material characteristics are thus created at the manufacturing stage (consolida tion), and these in themselves often give good possibilities regarding shape, so-called NS (Net Shape)-or NNS (Near Net Shape)-manufacture. The HIP-technique is used economically in the low series production of complex-shaped steel parts. In order to achieve quality products, an integration of material, design and manufacturing technology is necess ary, since the function and cost of the final component depends to a l arge extent on the development of production technology and its integr ation with design technology. Simulation of the hot isostatic pressing process is required to reduce the need for expensive and time-consumi ng experimental design. The use of finite element techniques in analys es of the highly non-linear process is preferable, especially for comp lex-shaped components. In this work, a micro-mechanical based continuu m mechanics model for finite element analysis is presented. The model is used in the finite element simulation of hot isostatic pressing of two components. The results from the analyses correspond well with the experimental results.