Synthesis and characterization of zircon sand/Al-4.5 wt% Cu composite produced by stir casting route Sanjeev Das V. Udhayabanu S. Das K. Das Received: 9 December 2004 / Accepted: 22 September 2005 / Published online: 2 May 2006 Ó Springer Science+Business Media, LLC 2006 Abstract Zircon sand particles of different size and amount have been incorporated in Al-4.5 wt% Cu alloy by stir casting route. Coarser particles of size between 90 and 135 lm can be dispersed in substantial amounts (up to 30 wt%), where as finer particles of size 15 and 65 lm have limited dispersion, 10 and 20 wt%, respectively. The matrix of the composites has cellular structure, where the size of the cell depends on zircon particle size and its amount in the composite. Segregation of copper rich phase (CuAl 2 ) has been found in the vicinity of the particle– matrix interface. The abrasive wear resistance of the composite improves with the increase in amount or decrease in size of zircon particles. Introduction Aluminum metal matrix composites (Al MMCs) are being considered as advanced materials for its light weight, high strength, high specific modulus, excellent wear resistance and low co-efficient of thermal expansion compared to conventional metals and alloys [1–3]. The excellent mechanical properties of these materials and the relatively low production cost make them very attractive for a variety of applications in automotive and aerospace industries. There are several fabrication techniques available in manufacturing the MMC materials. According to the type of reinforcement, the fabrication techniques can vary considerably. These techniques include stir casting [4–9], liquid metal infiltration [10], squeeze casting [11], and spray co-deposition [12]. Stir casting route is generally practiced commercially [13–15]. Its advantages lie in its simplicity, flexibility and applicability to large quantity production. Some of the Al matrix composites such as those reinforced with SiO 2 ,B 4 C, Al 2 O 3 or SiC are now commercially available in a variety of structural forms. Amongst the various aluminum–ceramic combinations limited studies are done on aluminum–zircon composite as zircon is not readily wetted by liquid aluminum and there is a significant difference between their density values. However, wetting characteristics of the liquid metal with the solid surface may quickly be altered by an appropriate alloying element addition. Despite having disadvantages in synthesizing aluminum–zircon composites, zircon was found to be a promising candidate due to its high hardness, high modulus of elasticity, and excellent thermal stability. Excellent thermal stability is important since fabrication processes undergo enormous changes in temperature, and large volumetric changes due to phase transformation can cause debonding at the interfaces [16]. In the present investigation, stir-casting route has been used for incorporating zircon sand particle of different size and amount in Al-4.5 wt% Cu alloy melt. It has been reported earlier that introduction of zircon in liquid alu- minum does not require the formation of a vortex [16]. However, in the present investigation stirring has been done for better distribution and to prevent sedimentation of zircon particles in melt. Effect of particle size and amount on particle distribution, particle settling and matrix struc- ture has been studied and correlated. Abrasive wear behavior of the monolithic alloy and as-cast composites has been evaluated and compared. S. Das V. Udhayabanu S. Das K. Das (&) Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur, Kharagpur, West Bengal 721 302, India e-mail: karabi@metal.iitkgp.ernet.in J Mater Sci (2006) 41:4668–4677 DOI 10.1007/s10853-006-0056-1 123