Minimization of the sintering distortion by study the influence of the sintering substrate

Contact

Yuanbin Deng © Copyright: IWM

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+49 241 80 99545

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Motivation

To become marketable, components should be possible to be supplied with precisely predictable and reproducible geometries, while the requirements for final dimension and form tolerance are always very high. Although powder compression combined with solid phase sintering are seen as a good solution due to its low shrinkage, there are still some problems for the mentioned wet shaping routes, for metal and ceramic powder injection moulding as well as for hard metal and cellular materials (sponge structures, hollow sphere structures) according to component geometry.

The significant reduction in development time via resource-saving simulation tool enables a fast response to dynamic market requirements and offers manufacturing companies high flexibility. This increases competitiveness on the national and international market. Furthermore, economic losses can be reduced by applying optimized sintering substrate, as a lower rejection rate can be achieved. Another motivation for the precise knowledge and prediction on sintering behaviour is quite meaningful in powder technical production of hard materials, which are used as tools, such as hard metals, cermets or technical ceramics. To comply with dimensional tolerances, these materials are often machined after sintering, e.g. grinding. Usually, this time-consuming and expensive final processing takes up the largest part of total production costs. Therefore, the reduction of the required manufacturing allowance by reproducible control of the sintering shrinkage contributes significantly to reducing the production costs. Both the production of the rejects and the machining of finished parts are great cost factors, which can weaken the profitability of the respective companies. The development of virtual preliminary studies and the application of low-distortion sintering substrates are resource-efficient alternatives that makes a reduced component allowance and lower rejection rate possible.

Objectives

  • Understanding of the influence of the substrate on the sintering behaviour.
  • Development of sintering models to simulate the sintering behaviour by considerating the friction between the green body and the sintering substrate.
  • Targeted modification of the sintering substrate to reduce distortion on sintered components.
  • Derivation of production rules for sintering process on the substrates (Dos and Don’ts)

Project contents

  • Experimental study on the effects of friction between the sintered product and the sintering substrate during sintering process
  • New optimization guidelines for substrates to produce correspondingly adjusted, low-friction substrates for distortion-free sintered components.
  • Simulation of sintering using a verified numerical model based on the experimental data to predict the sintering behaviours of new products with the consideration of the influence of the friction between the green body and the sintering substrate to avoid anisotropic shrinkage.

Project funding

FSV - AiF