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Full sintering of powdered-metal bodies in a microwave field

Nature volume 399, pages 668–670 (1999)Cite this article

An Erratum to this article was published on 16 September 1999

Abstract

The use of microwaves to process absorbing materials was studied intensively in the 1970s and 1980s, and has now been applied to a wide variety of materials1,2,3,4. Initially, success in microwave heating and sintering was confined mainly to oxide and some non-oxide ceramics5,6,7,8,9,10,11; but recently the technique has been extended to carbide semimetals12,13,14 used in cutting tools. Here we describe the microwave sintering of powdered metals to full density. We are able to sinter a wide range of standard powdered metals from commercial sources using a 2.45-GHz microwave field, yielding dense products with better mechanical properties than those obtained by conventional heating. These findings are surprising in view of the reflectivity of bulk metals at microwave frequencies. The ability to sinter metals with microwaves should assist in the preparation of high-performance metal parts needed in many industries, for example, in the automotive industry.

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Figure 1: Diagram of microwave system for sintering of powdered-metal parts.
Figure 2: Optical micrographs of two sets of ‘green’ (that is, unsintered) and microwave-sintered powdered–metal parts processed at 1,200?°C for 30 minutes.

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Acknowledgements

We thank J. Kosco for providing powdered-metal components. We also thank the approximately 20 corporations that supported the early stages of this work, which is now supported by the Electric Power Research Institute, the Keystone Powder Metal Company and the Ben Franklin Technology Center.

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Authors and Affiliations

  1. Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA

    Rustum Roy, Dinesh Agrawal, Jiping Cheng & Shalva Gedevanishvili

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  1. Rustum Roy
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Correspondence to Dinesh Agrawal.

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Roy, R., Agrawal, D., Cheng, J. et al. Full sintering of powdered-metal bodies in a microwave field. Nature 399, 668–670 (1999). https://doi.org/10.1038/21390

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