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A new method to prepare functionally graded material

IP.com Disclosure Number: IPCOM000210862D
Publication Date: 2011-Sep-13
Document File: 3 page(s) / 85K

Publishing Venue

The IP.com Prior Art Database

Related People

Wei Deng: AUTHOR [+4]

Abstract

In this article, a kind of new method (Layer-Layer method) to prepare polymer based functionally graded material is presented. Manufacture machine is partly mentioned. This method also could be used to prepare the green body for gelcasting ceramic. Functionally graded material (FuGM) could be used to relax local stress, such as electrical stress, mechanical stress, thermal stress, etc., via carefully controlling the distribution of selected components (1) Layer-layer casting method could be used to cast big part. The bigger the parts, the easier of this method, in comparison with centrifugation method, or other manufacture method. (2) This method could be used to prepare functionally graded material, ranging from graded permittivity, thermal conductivity, mechanical modular, etc. (3) With this method, the adhesive forces between different layers are maximized. (4) The products made by this method could be easily detected, by cutting slices of part from different directions, since the characteristic layer structure, or graded particle concentrations.

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Page 01 of 3

Fabricate FuGM Wei Deng, Viki Li, Huigang
Sun, Angela Zhang

      A new method to prepare functionally graded material Principal Applications/Uses of the Invention

1. In this article, a kind of new method (Layer-Layer method) to prepare polymer based functionally graded material is presented. Manufacture machine is partly mentioned. This method also could be used to prepare the green body for gelcasting ceramic.

2. Functionally graded material (FuGM) could be used to relax local stress, such as electrical stress, mechanical stress, thermal stress, etc., via carefully controlling the distribution of selected components

Problem Overcome by the Invention

   Thermoset polymer is widely used in ABB's power products, mainly as insulation material. FuGM type thermoset could be very useful in some cases, and help to lower cost,

   Manufacture method is one of the biggest challenges for the practical application of FuGM in power products. This invention focuses on a kind of new manufacture method, which has not been reported before.

Some potential examples might be benefitted from this method:
1. Bowl like GIS spacer insulator, graded permittivity with desired distribution could relax the local electrical stress near triple points in HV GIS.

2. Air cooling type spout in MV AIS, with better thermal emission ability in non-mechanical bearing part, and better mechanical property in mechanical stress points.

Detailed Description of the Invention

   Nagoya University reported the manufacture of FuGM type insulation part with U shape permittivity distribution, via centrifugation method. However, a HV spacer insulator with mold may be as heavy as hundreds of kilograms, and it is not easy to rotate such a big block with required speed.

   Here, we introduce one kind of layer-layer method to prepare the thermoset based functionally graded material, without centrifugal machine.

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   As described in the figure, different layers of fluid (reactive monomer, such as epoxy resin + hardener, and fillers) are casted in the mold separately. Later, the multi-layers are crosslinked by heating the mold to desired temperature. Depending on practical manufacture task and setup, the different reaction mixtures could be casted into mold via single tube gradually, or multi-tubes separately; the working situation could be atmosphere, or under vacuum.

   During this process, there are 2 main challenges. One is the sedimentation, and another is the disturbance between different layers.

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9-25-2010

Revision Page


Page 02 of 3

Fabricate FuGM Wei Deng, Viki Li, Huigang
Sun, Angela Zhang

(1) For the sedimentation, smaller filler could be helpful, to solve the problem.
(2) For the disturbance between different layers, the theory of Rayleigh-Taylor could provide useful hint. A simplified description is that, the lower layer with higher density and high visco...