FEM-Based Modelling of Elastic Properties and Anisotropic Sinter Shrinkage of Metal EAM
Tobias Rosnitschek, F. Hueter, Bettina Alber-Laukant
Abstract
The fabrication of nearly fully dense metal parts via additive material extrusion processes is an auspicious alternative to powder-bed-based methods. After the extrusion of the material, the parts are debindered and sintered. Due to the process, the shrinkage of the parts and the material behaviour is orthotropic which causes problems to obtain the desired dimensional accuracy. Classical methods for simulating the sinter process are complex and demand the knowledge of various material parameters that have to be determined experimentally. This paper discusses analytical and numerical methods for predicting the effective properties of additively fabricated parts and presents a new and simple approach for the prediction of shrinkage, warpage and internal stresses caused by the sintering process based on a thermomechanical finite element analysis. The presented framework can be used to model the material behaviour without the need of extensive experimental data and is adaptable to various machines and materials. The proposed approach is exemplary shown. The results validate its functionality to predict sinter induced shrinkage and warpage as well as the locations of maximum internal stresses.