Influence of porosity and impurities on the thermal conductivity of pressure-less sintered Cu powder green bodies

ABSTRACT

Copper as a material with a high electrical and thermal conductivity awakes large interest for many applications in industry, e.g. thermal management of electronic components. Powder-based manufacturing techniques (e.g. Selective Laser Melting, Binder Jetting, Fused Filament Fabrication and Metal Injection Molding) enable the complex shaping of metals. Especially the methods without melting processes like Binder Jetting, Fused Filament Fabrication and Metal Injection Molding have a great potential for complex Cu structures. These techniques built up a powder-based green body and require a subsequent sintering step to reach a high density with maximum properties. This work reports the development of the heat conductivity during pressure-less sintering of Cu powder green bodies. The experimental results are compared to analytical models and a numerical simulation and show the limits of the reachable heat conductivity depending on the remaining porosity and the impurity concentration.

KEYWORDS:

• porosity
• thermal conductivity
• copper
• sintering
• powder metallurgy

Acknowledgements

The author wants to thank the associates from the metallography lab at Saarland University as well as from the analytics department at the corporate sector research at Bosch for their support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Notes on contributors

Jonas Ott

Jonas Ott studied Material Science at the University of Stuttgart at the institute of material physics. Currently, he is part of the Ph.D.-program at the Robert Bosch GmbH in the corporate sector research in cooperation with the institute of functional materials at the Saarland University.

Andreas Burghardt

Andreas Burghardt received his Ph.D. in Material Science from Karlsruhe Institute of Technology in 2009. He works as Senior Expert in the Corporate Sector Research and Advance Engineering of Robert Bosch GmbH on processing, properties and application of sintered metals and ceramics.

Dominik Britz

Dominik Britz Studied Material Science at Saarland University. After receiving his Diploma degree at the Chair of Functional Materials, he completed his doctorate in the area of characterization, quantification and classification of microstructures. Since 2014 he manages the Material Engineering Center Saarland (MECS) together with Prof. Mücklich, is group leader at the Chair of Functional Materials at Saarland University and founded the Surfunction GmbH in 2020.

Frank Mücklich

Professor Frank Mücklich heads the Institute for Functional Materials in the Department of Materials Science and Engineering at Saarland University and is Chairman of the European School for Materials (EUSMAT) as well as Director of the transfer-oriented Material Engineering Center Saarland (MECS). His research focuses on 3D microstructural research on the micro-, nano- and atomic scale, surface functionalization by interfering laser beams (DLIP) and the development of new metallic structural and functional materials. He has published more than 400 scientific papers, holds 12 patents and is editor of the international application-oriented journal “Practical Metallography - Preparation, Imaging and Analysis of Microstructures” (De Gruyter Publisher). Prof. Mücklich received numerous scientific awards for his work in these fields and was recently appointed as Fellow of the American Society for Materials (ASM), elected into the German Academy of Engineering Sciences (ACATECH) and was also President of the German Society for Materials (DGM).