Original Research Article An investigation into fabrication and characterization of direct reaction synthesized Al-7079-TiC in situ metal matrix composites S.V. Sujith a, * , Manas Mohan Mahapatra b , Rahul S. Mulik a a Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Uttrakhand 247667, India b School of Mechanical Sciences, Indian Institute of Technology, Bhubaneswar, Odisha 751013, India 1. Introduction During the past decade aerospace and automobile industries are becoming more challenging due to the specific property requirements where conventional alloy systems are not sufficient. Attempts to improve the performance character- istics of aluminum alloys with a high strength second phases are required for high strength to weight ratio [1]. Metal matrix composites (MMCs) incorporate a broad variety of metal systems (e.g. titanium, aluminum, magnesium, copper and nickel alloys) using various reinforcements in the form of fibers (Al 2 O 3 , SiC, graphite), whiskers (SiC) and particulate reinforcing phases (SiC, Al 2 O 3 , B 4 C, TiC, TIB 2 ) [2,3]. High quality a r c h i v e s o f c i v i l a n d m e c h a n i c a l e n g i n e e r i n g 1 9 ( 2 0 1 9 ) 6 3 – 7 8 a r t i c l e i n f o Article history: Received 28 May 2018 Accepted 11 September 2018 Available online Keywords: In situ Reaction synthesis Mechanical testing Metallography a b s t r a c t The present study was attempted to highlight a novel direct reaction synthesis in which traditional casting plus rapid solidification techniques were implemented to produce Al- 7079-TiC in situ composites with homogenous microstructure and improved dispersion strengthening by the reinforcing phases. Casted samples were effectively characterized by scanning electron microscopy followed by energy dispersive spectroscopy and X-ray dif- fraction. Ingot metallurgy showed a homogenous distribution of TiC particles inside the grain. This particle behavior acted as an excellent nucleation sites for the Al dendrites to grow unvaryingly. TiC reinforcements have semi coherent relationship with a-Al matrix. It was observed that eutectic boundary includes the second phases based on h (MgZn 2 ) and Mg (Zn, Cu, Al) 2 . Almost 90% of the in situ reinforced TiC were homogenously distributed along the center of the grain. Thermal history conditions have shown an exothermic behavior during casting. Experimental results revealed the evolution of TiC particles in super-heated melt region, i.e. dissolution of titanium continued by reaction of titanium with diffused carbon in the Al matrix to form TiC particles. Further they acted as nucleation sites for the a- Al dendrites to grow homogenously. This study presents optimum process temperature for the Al-TiC in situ synthesis. © 2018 Politechnika Wroclawska. Published by Elsevier B.V. All rights reserved. * Corresponding author. E-mail addresses: sujithsv88@gmail.com (S.V. Sujith), manasfme@gmail.com (M.M. Mahapatra), rsm@iitr.ac.in (R.S. Mulik). Available online at www.sciencedirect.com ScienceDirect journal homepage: http://www.elsevier.com/locate/acme https://doi.org/10.1016/j.acme.2018.09.002 1644-9665/© 2018 Politechnika Wroclawska. Published by Elsevier B.V. All rights reserved.