Technical Paper: PIM International, Vol.2 No. 3 September 2008, pages 69-71, 1351 words

Authors: Luc Federzoni and Pascal Revirand

CEA Grenoble LITEN 17 rue des Martyrs , F-38054 Grenoble cedex 9, France

Abstract

This work concerns the development of an innovative processing route for manufacturing a new design of ceramics micro-channelled heat exchanger. The manufacture is based principally on the Ceramic Injection Moulding process of the different elements of the micro-channelled heat exchanger. Furthermore, the different elements are co-fired in order to produce the part. The micro-channelled heat exchanger is characterised by a complex network of inner channels. The paper focuses on the alumina feedstock based on ultrafine alumina powders and on conditions of injection, debinding and co-firing, developed essentially for this study. Moreover, interfaces between the co-fired elements have been characterised by optical microscopy. This process may be applied to design complex and precise microstructures for mass produced micro-channelled heat exchangers, cold plates and micro reactors than can be used for various large scale applications in the field of energy and electronic cooling.

Introduction

Micro powder injection moulding (or micro-PIM) is a technique which has been largely developed in recent studies [1-9]. This technique can be used for manufacturing micro parts for large-scale production. This process also allows the replication of very fine details, typically in the order of magnitude of the size of the powder. However, the development of feedstock for micro-PIM with nanopowders is difficult as the viscosity of the feedstock then increases drastically [2]. The majority of feedstocks for microPIM are therefore composed of micrometer size powder. They allow replicating details of a few tenths of a micrometer [1].

Among several applications, micro heat exchangers appear to be an important issue for micro-PIM. Several demonstrators have been manufactured by several authors [10, 11], until now.

In this research work, a process chain to perform a complete micro heat exchanger has been developed and we have set-up the complete process for the manufacturing of this type of complex 3D part including:.....

Further sections of this article include:

- Experimental
- Ceramic powder
- Injection of the plates
- Debinding cycle
- Sintering cycle

- Results
- Feedstock preparation
- Injection of the part
- Co-firing results

- Conclusions
- Acknowledgments
- References

Figures and Tables:

Fig. 1 Sketch of fabrication of the heat exchanger

Fig. 2 Structure of the heat exchanger

Fig. 3 Final part with a green plate for comparison

Fig. 4 Optical microscopy of the interface between 2 plates at different magnifications

Table 1 Size of the powders used in this study

Table 2 Compositions of the optimised feedstock

Table 3 Binder removal at debinding stage