Mould filling simulations during powder injection moulding

Mould filling simulations during powder injection moulding

Bilovol, V.V.

Katgerman, L. (promotor)
Duszczyk, J. (promotor)

Applied Sciences

2003-06-02

Powder injection moulding (PIM) is a versatile technology capable of producing complex and near net shape parts. Significant help in optimisation of the PIM process can be obtained from the numerical simulation. To obtain realistic numerical results it is necessary to fulfil certain conditions. The material properties should be correctly determined in the conditions close to those during the real powder injection moulding. The process must be described with the appropriate mathematical model. Also proper initial and boundary conditions must be chosen. In this study a standard feedstock of stainless steel 316 L produced by BASF AG has been characterised for determining the input parameters for the numerical simulation. Viscosity of the feedstock was measured in the wide range of shear rates at four temperatures using the capillary rheometer. Specific heat of the studied feedstock was measured with an advanced DSC apparatus at different cooling rates. The obtained data were found suitable to serve as the input parameters for the simulation of the powder injection moulding process. Simulation of the PIM process using a material model for a Generalised Newtonian Fluid has been performed with three best known commercial packages, C-Mold, Moldflow and ProCAST. The obtained simulation results have been compared with each other and with the experimentally determined ones (melt front advancement, weld line locations, in-cavity temperatures and pressures). It has been proven that the PIM process can be successfully simulated with C-Mold, Moldflow and ProCAST analysis packages. The flow pattern predicted by C-Mold appeared to be less accurate than that predicted by ProCAST and Moldflow. The predictions of the locations of weld lines made by all three analysis packages were in good agreement with the experimental observations, but ProCAST yields the best results. The temperatures of the feedstock predicted in the simulations were in good agreement with the experimentally measured ones. The best predictions of pressure were made by C-Mold. The predicted by C-Mold in-cavity pressure value matched well the experimentally observed one. ProCAST underestimated the in-cavity pressure by 20-30%. The Moldflow pressure results were found to be 3-4 times lower than the experimentally observed ones. Despite minor drawbacks, ProCAST was found to be the best analysis package for the numerical simulation of the PIM process.

powder injection moulding
numerical simulation
stainless steel

http://resolver.tudelft.nl/uuid:3d24a18f-5e34-4cc1-997c-0e886cda1b18

Delft University of Technology

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Institutional Repository

doctoral thesis

(c) 2003 V.V. Bilovol