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Effect of Equal Channel Angular Pressing on the Microstructure and Mechanical Properties of Hybrid Metal Matrix Composites


  • Department of Mechanical Engineering, Government Engineering College, K.R. Pet, Mandya – 571426, Karnataka, India
  • Department of Mechanical Engineering, Siddaganga Institute of Technology, Tumkur - 572103, Karnataka, India


Objectives: The objective of the present study is to prepare Al6061-Gr-SiChybrid composites by stir casting route and the effect of Equal Channel Angular Pressing (ECAP) on the microstructure and mechanical properties of Al6061-Gr-SiC hybrid composites will be evaluated. Methods: In the present study, Al6061 is selected as matrix material. The reinforcement materials chosen are graphite (Gr) and Silicon carbide (SiC) particles of 10-30 μm size. The hybrid composites have been prepared by stir casting route in which the amount of Gr particles are kept at 3wt% and SiC particles are varied from 2-10wt% in steps of 2wt% . The cast hybrid composites are subjected to annealing treatment at 400oC for 4 hours and specimens have been prepared from these composites for ECAP process. The ECAP process was carried out at room temperature using a die with channel angle of 120o and Bc route was adopted for successive passes. The influence of ECAP on microstructure and mechanical properties of Al-Gr-SiC hybrid composite was evaluated. Findings: The microstructural study revealed that the composites are free from defects and also the distribution of reinforcement particles in the matrix are fairly uniform. Significant improvement in micro hardness and tensile strength was observed as the wt% of SiCp increases in as cast Al6061-Gr- SiC hybrid composites. After ECAP process, the size and distribution of the reinforcement particles are not changed but significant reduction in the grain size of the matrix alloy was observed. The micro hardness and tensile test results revealed that, there is a significant improvement in the micro hardness and the Ultimate tensile strength of ECAP processed hybrid composites. The enhancement in mechanical properties are mainly attributed to the grain refinement of the matrix alloy and strain hardening of hybrid composite materials by ECAP process. Applications: The ECAP process had a profound effect in enhancing the mechanical properties of hybrid composites. These composite materials have great impact in automobile, military and aerospace industries.


Al6061, ECAP, Hybrid Composites, Mechanical properties, Stir Casting, Silicon Carbide.

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  • Surappa MK. Aluminium matrix composites: Challenges and Opportunities. Sadana. 2003; 28:319–34.
  • Satyanarayana KG, Pillai RM, Pai BC. Developments in Science and Technology of Cast Aluminium Matrix Composites – An overview. TMS Annual Meeting and Exhibition, USA. 2006; 51–61.
  • Siva Konda Reddy B, Varaprasad J, Naveen Kumar Reddy K. Matrix Al-Alloys for Silicon Carbide Particle Reinforced Metal Matrix Composites. Indian Journal of Science and Technology. 2010 Dec; 3(12). Doi:10.17485/ijst/29858.
  • Lokesh T, Mallikarjun US. Mechanical and Morphological Studies of Al6061-Gr-SiC Hybrid Metal Matrix Composites. Applied Mechanics and Materials (Trans Tech publications). 2015; 813-814:195–202.
  • Mahajan G, Karve N, Patil U, Kuppan P, Venkatesan K. Analysis of Microstructure, Hardness and Wear of Al-SiC-TiB₂ Hybrid Metal Matrix Composite. Indian Journal of Science and Technology. 2015; 8(S2):101–5.
  • Mallikarjuna HM, Ramesh CS, Koppad PG, Kashyap KT, Keshavamurthy R. Microstructure and Micro hardness of Carbon Nanotube-SiliconCarbide/Copper
  • Hybrid Nanocomposite Developed by Powder Metallurgy. Indian Journal of Science and Technology. 2016 Apr; 9(14). Doi:10.17485/ijst/84063.
  • Syed KH, Anuraag GP, Hemanth G, Subahan SA. Powder-Mixed EDM Machining of Aluminium-Silicon Carbide Composites. Indian Journal of Science and Technology. 2015 Jan; 8(S2). Doi: 10.17485/ijst/59170.
  • Rohatgi PK, Ray S, Liu Y. Tribological Properties of Metal Matrix-Graphite Particle Composites. International Materials Review. 1992; 37(3):129–49.
  • Surappa MK, Rohatgi PK. Preparation and properties of cast aluminium -ceramic particle composites. Journal of Materials Science. 1981; 16:983–93.
  • Srivatsan TS, Ibrahim IA, Mohamed FA, Laverna EJ. Processing techniques for particulate reinforced metal aluminum matrix composites. Journal of Materials Science. 1991; 26:5965–78.
  • Hashim J, Louney J, Hashmi MSJ. Particle distribution in cast metal matrix composites: Part –I. Journal of Materials and Material Process Technology. 2002; 123:251–7.
  • Valiev RZ, Islamgaliev RK, Kuzmina NF, Li Y, Langdon TG. Strengthening and grain refinement in an Al6061 metal matrix composites through intense plastic straining. Scripta Metallurgica. 1999; 40:117–22.
  • Nakashima K, Horita Z, Nemoto M, Langdon TG. Influence of channel angle on the development of ultrafine grains in equal channel angular pressing. Acta Metallurgica. 1998; 46:1589–99.
  • Aida T, Matsuki K, Horita Z, Langdon TG. Estimating the equivalent strain in equal channel angular pressing. Scripta Metallurgica. 2001; 44:575–9.
  • Horita Z, Fujinimai T, Nemato M, Langdon TG. ECAP of Commercial Aluminium Alloys: grain refinement, Thermal stability, and tensile properties. Scripta Metallurgica. 2000; 31(A): 693–9.
  • Shokuhfar A, Nejadseyfi O. Comparisons of the effect of sever plastic deformation and heat treatment on the tensile properties and impact toughness of aluminum alloy 6061. Materials Science and Engineering A. 2014; 594:140–8.
  • Iwahashi Y, Furukawa M, Horita Z, Nemoto M, Langdon TG. Microstructural characteristics of ultrafine grained aluminum produced using Equal Channel Angular Pressing. Journal of Metals and material Transactions. 1998; 29(9):2245–52.
  • Li Y, Langdon TG. Equal-Channel Angular Pressing of an Al6061 Metal Matrix Composite. Journal of Materials Science. 2000; 35:1201–14.
  • Ma D, Wang J, Xu K. Equal Channel angular pressing of SiCw reinforced aluminum based composites. Materials Lett. 2002; 56:999–1002.
  • Saravanan M, Pillai RM, Ravi KR, Pai BC, Brahmakumar M. Development of ultrafine grain aluminium-graphite metal matrix composite by equal channel angular pressing. Composite Science and Technology. 2007; 67(7):1275–80.
  • Tirton I, Guden M, Yildiz H. Simulation of the strain rate sensitive flow behavior of SiC-particulate reinforced aluminium metal matrix composites. Computational Materials Science. 2008; 42:570–8.
  • Ramu G, Bauri R. Effect of equal channel angular pressing (ECAP) on microstructure and properties of Al-SiCp composites. Materials and Design. 2009; 30:3554–9.
  • Semiatin SL, Delo DP, Sheli EB. The effect of material properties and tooling design on deformation and fracture during equal channel angular extrusion. Acta Material. 2000; 48:1841–51.
  • Arsenault RJ, Wang L, Feng CR. Strengthening of composites due to Microstructural changes in the matrix. ActaMetallurgica. 1991; 39:42–52.
  • Arsenault RJ, Shi N. Dislocation generation due to differences between the coefficients of thermal expansions. Material science and Engineering. 1986; 81:175–87.
  • Mummery P, Derby B. The influence of microstructure on the fracture behavior of particulate metal matrix composites. Material science and engineering A. 1991; 135:221–4.
  • Xu C, Furukawa M, Horita Z, Langdon TG. The evolution of homogeneity and grain refinement during equal channel angular pressing: A model for grain refinement in ECAP. Material Science and Engineering A. 2005; 398:66–76.


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