Vol.:(0123456789) 1 3 Journal of Thermal Analysis and Calorimetry (2020) 142:175–182 https://doi.org/10.1007/s10973-020-09741-5 Evaluation of thermal properties of MMCp composites with silver alloy matrix Jakub Wieczorek 1  · Tomasz Maciąg 2  · Karolina Kowalczyk 1  · Damian Migas 1 Received: 25 August 2019 / Accepted: 23 April 2020 / Published online: 13 May 2020 © The Author(s) 2020 Abstract Silver, silver alloys, and composites with silver matrix are used mainly as electric contacts, circuit-breakers, and slide bear- ings. Contacts working conditions require as high as possible thermal and electrical conductivity, wear resistance during electric arc work, low susceptibility to tacking, and chemical stability. Unreinforced silver alloys do not meet those expecta- tions, hence increasing interest in metal matrix composites. Reinforcing with ceramic particles improves tribological wear resistance and minimizes formability of silver alloys. At the same time, introduction of ceramic particles decreases thermal and electrical conductivity. In this paper, manufacturing method of silver-based composites reinforced with particles Al 2 O 3 , SiC, and glassy carbon was described. Composites were subjected to differential thermal analysis. Furthermore, thermal diffusivity measurements using laser flash method, as well as measurements of linear thermal expansion coefficient using dilatometric method were performed in order to determine heat conductivity of the prepared composites. Keywords Thermal analysis · MMCP · Composites · Silver matrix · Suspension method Introduction The application of metal matrix composites (MMCs) is common in industry [1–4]. Composites based on light metal alloys (aluminum, magnesium) are used in automotive and aerospace industries owing to their low density and simple manufacturing methods [5–7]. Composites based on nickel characterized by high-temperature creep and corrosion resistance are broadly used in space technology and avia- tion [8, 9]. Zinc- and lead-based composites have good slid- ing properties and abrasion resistance [4, 10]. Additionally, composites based on silver and copper are used as a contacts in electronics and electrotechnics due to high thermal and electrical conductivity. Furthermore, the Ag- and Cu-based composites are utilized as conductive elements, junctions or terminals [3, 11, 12]. A material dedicated for electric contacts should not change properties after numerous connections, after longer shut-down breaks, and during ongoing current passing. At the same time, it should by characterized by high thermal and electric conductivity preventing from excessive tem- perature rise in contacts, as well as by high melting tem- perature ensuring material resistance to welding and tack- ing [13]. Pure silver has the highest thermal and electrical conductivity and the lowest contact resistance among all metals. Due to significant workability and susceptibility to corrosion caused by sulfur oxides from the atmosphere, silver alloys are applied in industry. Alloying additions such as copper, zinc, manganese, cadmium, nickel, and aluminum increase endurance, wear resistance, sparking resistance, and corrosion resistance of silver alloys [13]. Nevertheless, those materials are susceptible to electric arc, erosion, and have poor weighting strain resistance. In order to improve those properties, reinforcing particles may be introduced into the alloy in a shape of pure ele- ments, carbides or oxides, obtaining in this way MMCp composites with silver alloy matrix [14]. Reinforcing with particles has advantageous impact on hardness, resistance to adhesive and tribological wear, however, it decreases * Tomasz Maciąg tomasz.maciag@polsl.pl * Damian Migas damian.migas@polsl.pl 1 Department of Advanced Materials and Technologies, Silesian University of Technology, Krasińskiego 8 st., 40-019 Katowice, Poland 2 Department of Metallurgy and Recycling, Silesian University of Technology, Krasińskiego 8 st., 40-019 Katowice, Poland