Materials Science and Engineering A 502 (2009) 91–98 Contents lists available at ScienceDirect Materials Science and Engineering A journal homepage: www.elsevier.com/locate/msea Cast in situ Cu–TiC composites: Synthesis by SHS route and characterization S. Rathod a , O.P. Modi a,∗ , B.K. Prasad a , A. Chrysanthou b , D. Vallauri c , V.P. Deshmukh d , A.K. Shah d a Advanced Materials and Processes Research Institute, CSIR, Bhopal 462026, India b School of Aerospace, Automotive and Design Engineering, University of Hertfordshire, Hatfield, Herts, UK c Department of Materials Science and Chemical Engineering, Polytecnico di Torino, Italy d Naval Materials Research Laboratory, Ambernath, India article info Article history: Received 5 August 2008 Received in revised form 3 October 2008 Accepted 6 October 2008 Keywords: Metal matrix composites (MMCs) In situ Cu–TiC composites Microstructure Self-propagating high temperature synthesis (SHS) Casting abstract The present investigation discusses observations pertaining to the synthesis of Cu-based composites con- taining TiC particles in the range of 45–50 volume % by self-propagating high temperature synthesis (SHS) process. A composite with 11–13 volume % TiC dispersion was also synthesized through remelting and dilution. The composites were observed to contain a copper matrix together with a Cu–Ti intermetallic compound, TiC dispersoid particles and partially reacted graphite. The regions showing partially reacted graphite (carbon) became less prominent in the diluted composites. Al addition led to the refinement of TiC particles, higher hardness, reduced density and improved degree of formation and better homogene- ity of the distribution of TiC particles. Dilution caused reduced hardness, while the density followed a reverse trend. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Copper is an attractive material for a wide range of applications in the engineering and power generation industries because of its good electrical and thermal conductivities in addition to chemical stability [1–8]. However, pure copper is a soft metal and possesses poor high-temperature strength leading to premature failure of components in service [1,5,6,8]. Copper-based alloys like brasses and bronzes are conventionally used for naval applications, but suffer from problems like dezincification (corrosion) and inferior elevated temperature properties. The latter problem results from the coarsening of the less stable microconstituents [2,8] thereby greatly limiting their uses. Hence there lies a challenge to improve the elevated temperature properties of Cu and its alloys without adversely affecting their high thermal and electrical conductivities and corrosion resistance. Copper-based metal matrix composites containing ceramic par- ticulates have attracted wide interest during recent years [1–8]. These composite materials possess excellent thermal and electrical conductivities, high temperature strength and good microstruc- tural stability [1,2]. Titanium carbide is an attractive ceramic compound for use as a reinforcing material in metallic matrices ∗ Corresponding author. Tel.: +91 755 2485085; fax: +91 755 2488323. E-mail address: om prakashmodi@yahoo.com (O.P. Modi). like Cu, Fe, Ni, Al and Ti because of its high modulus, hardness and melting temperature [1,2,9–12]. During recent years, copper-based metal matrix composites containing TiC particles have exten- sively been investigated because of their potential applications as electrical sliding contacts, resistance welding electrodes, high performance switches, motors, heat exchangers, electrodes, etc. [3,13–15]. These composites have been synthesized primarily by powder metallurgy routes, infiltration techniques as well as com- pocasting. [3,13–15]. The addition of TiC/TiB 2 particles has led to improved stiffness, hardness, tensile and wear properties and a decrease in the coefficient of thermal expansion of the composites [16]. Furthermore, the reduction in electrical and thermal conduc- tivities due to the addition of TiC to the copper matrix has been noted to be much less in comparison to most other ceramic rein- forcement particles [16,17]. Incorporation of TiC particles to metallic matrices like Cu through external means presents problems like segregation of the dispersoid phase and poor (TiC/matrix) interfacial bonding due to the high contact angle between the Cu melt and TiC particles [18]. Accordingly, the composites so synthesized attain inferior mechan- ical properties. In situ generation of the dispersoid phase from within the melt has been suggested to reduce the severity of the mentioned problems. One of the most important methods of gen- erating TiC in situ in metallic matrices such as copper has been observed to be the self-propagating high temperature synthesis (SHS) process [19,20]. In this process, chemical reactions between 0921-5093/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.msea.2008.10.002