Powder injection moulding
Manufacturing of Versatile Ceramic or Metal Micro Components by Powder Injection Moulding
V. Piotter, K. Plewa, J. Prokop, A. Ruh, H.-J. Ritzhaupt-Kleissl, J. Hausselt
Forschungszentrum Karlsruhe, Institute for Materials Research III P.O. Box 3640, 76021 Karlsruhe, Germany
Abstract
Although microsystems technologies products have been steadily launched worldwide markets the development and improvement of manufacturing processes suitable for medium or large-scale production is still one of the most important prerequisites.
A well-known technology to meet such demands is micro injection moulding which has already reached an industrial viable status for polymeric materials. Nevertheless, there is still a lack of methods for the processing of materials with a wider range of properties.
A promising option to close this gap, development of the so-called MicroPIM process to facilitate the fabrication of metal and ceramic micro components was started.
Presently, the smallest dimensions achievable are 25-50μm of part thickness or minimum structural details of less than 5μm. Theoretical densities of up to 99% were achieved depending on the particular powder applied. As further improvement, the technology to produce rotational-symmetric parts by making use of a special head spindle system has been developed.
To enlarge the application possibilities of MicroPIM further, micro two-component injection moulding enables, for example, the fabrication of micro components consisting of two ceramic or metal materials with different physical properties and, not less important, significantly minimises assembly expenditure.
| 173 reads | SPH Simulation of the Embossing and Injection Moulding of Micro-Parts: Softening and Aggregation Aspects
D. Kauzlarić(a), L. Pastewka(b), C. Bretthauer(a), A. Greiner(a), J. G. Korvink(a)
a: Department of Microsystems Engineering (IMTEK), University of Freiburg, Germany
b: Fraunhofer Institute for Mechanics of Materials, Freiburg, Germany
Abstract
We present an approach based on Smoothed Particle Hydrodynamics (SPH) for the predictive simulation of ultrasonic embossing and injection moulding of micro-components. The material is represented by a set of moving fluid particles, carrying all relevant physical information. In order to discretise arbitrary transport equations, the idea of interpolation over the discrete particle data is used. We use this approach for the non-isothermal modelling of embossing of polymers and for the injection moulding of feedstocks with suspended powder particles (powder injection moulding, PIM). For the former we incorporate softening by introducing a temperature dependent yield-stress model based on viscosity regularisation. For the simulation of powder filled feedstocks, we perform an SPH-discretisation of a continuum model for particle migration. For both models, simulation results are presented for engineering relevant mould geometries. The embossing simulations show a softening below the glass transition temperature. The simulation of powder injection moulding shows an aggregation of the solid particles, eventually leading to failures during sintering.
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