A simplified approach to predicting dimensional changes during sintering using Finite Element Analysis (FEA).

Due to density gradients present in green P/M compacts, it is difficult to accurately predict dimensional changes that occur during sintering. Moreover, these changes are often non-uniform and may lead to distorted sintered parts. Usually, a trial and error approach is used to determine process parameters that will generate parts within specifications. Recently, Finite Element Analysis (FEA) has started to be used in P/M to simulate powder behavior during sintering. Obtained results are used to predict the final shape of the parts. This paper presents a simplified FE Simulation approach of the sintering process. This approach is based on a continuum mechanics formulation and a simplified viscous behavior model. It was used to simulate the sintering of an industrial two level bushing. Predicted final shapes were typically within 0.001 in. from experimental results, while final relative density distributions were typically within 1% of the experimental final density maps.