Copper–graphite composites: thermal expansion, thermal and electrical conductivities, and cross- property connections Aref Mazloum 1 , Jaroslav Kova ´c ˇik 2 ,S ˇ tefan Emmer 3 , and Igor Sevostianov 1, * 1 Department of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, NM 88001, USA 2 IMMM SAS, Dúbravská cesta 9, 84513 Bratislava, Slovakia 3 Institute of Technologies and Materials, Slovak University of Technology, IVMA STU Pionierska 15, 83102 Bratislava, Slovakia Received: 31 March 2016 Accepted: 12 May 2016 Ó Springer Science+Business Media New York 2016 ABSTRACT The paper focuses on thermal and electrical properties of copper–graphite composites. Copper–graphite composites in the range of 0–50 vol% of graphite were prepared from the mixture of copper and graphite powder by the powder metallurgy method. Such composites combine high thermal and electrical con- ductivities provided by copper matrix and low thermal expansion coefficient and lubricating properties due to the graphite phase. We model thermal and electrical conductivities and thermal expansion coefficient using methods of micromechanics in connection with the material microstructure and measure these quantities experimentally to compare with the results of modeling. Cross- property connections between thermal and electrical properties of the com- posites are established and experimentally verified. Introduction The paper focuses on thermal and electric properties of copper–graphite composites that combine high thermal and electrical conductivities provided by copper matrix and low thermal expansion coefficient and lubricating properties due to graphite phase [1]. Another advantage of such composites is very low chemical reaction between the graphite and copper phases—only a mechanical bond is usually formed between them [2]. We develop micromechanical model for thermal and electrical conductivities and thermal expansion coefficient of the composite (copper-containing graphite flakes) and cross-prop- erty connections between them and validate the model by experimental measurements. Copper–graphite composites reinforced with gra- phite particles attract attention of researchers for more than 25 years [3–5]. Initially, research and development of such composite has been focused on classical industrial applications such as (1) brushes for starters or welding machines and (2) sliding parts of pantographs for trains and trams. In this first application, low voltage and high current densities are required and copper–graphite composites with high specific electrical conductivity, satisfactory Address correspondence to E-mail: igor@nmsu.edu DOI 10.1007/s10853-016-0067-5 J Mater Sci