American Journal of Engineering Research (AJER) 2017 American Journal of Engineering Research (AJER) e-ISSN: 2320-0847 p-ISSN : 2320-0936 Volume-6, Issue-7, pp-181-190 www.ajer.org Research Paper Open Access www.ajer.org Page 181 Investigating the Influence of Casting Parameters on the Mechanical and Microstructural Characteristics of Grade Al6063 Alloy 1* Ajide O.O., 2 Oyedele J.O., 1 Salau T.A.O. and 1 Abu R. 1 Department of Mechanical Engineering, University of Ibadan, Ibadan, Oyo state, Nigeria. 2 Department of Mechanical Engineering, University of Texas, Tyler, USA Corresponding Author: Ajide O.O ABSTRACT: Influence of casting parameters on the mechanical properties and microstructure of alloys is gaining more prominent research concerns. The main aim of this work is to investigate the effect of three main casting parameters (Pouring temperature, pouring speed and pouring height) on the mechanical and microstructural characteristics of Al6063. The Al6063 obtained in billet form, was processed into cylindrical shape of length 20 cm and diameter 2 cm by casting. Fifteen cast samples were obtained at varying pouring temperatures, pouring speeds and pouring heights. Tensile, impact and hardness tests were performed. The samples were thereafter examined using optical metallurgical microscope. Results showed that enhanced mechanical and microstructural characteristics were obtained at the pouring temperature of 730 o C, pouring speed of 1.75 cm/s, and at pouring height of 15 cm relative to the as-received Al6063 aluminium alloy. This can be attributed to the effect of grain refinement during recrystallization and solidification as there was increase in the total grain boundary area capable of impeding to certain extent dislocation motion. In addition, it can be inferred that there exist also grain growth occurrences and the emergence of precipitates Mg 2 Si in the alloy and this perhaps was responsible for the observed considerable increase in hardness. Keywords: Al6063, Pouring temperature, Pouring speed, Pouring height and Mechanical properties --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 13 -05-2017 Date of acceptance: 20-07-2017 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION The 6xxx-group aluminium alloys are well known for its immense excellent properties and this has been responsible for its widespread applications (especially in the automobile, building services and aircraft industries). The 6xxx series contain silicon (Si) and magnesium (Mg) as main alloying elements (Aluminium Standard and Data, 1988). These alloying elements are partly dissolved in the primary -Al matrix, and partly present in the form of inter-metallic phases. As reported by Siddiqui et al. (2000), a range of different inter- metallic phases may be formed during solidification, depending on alloy composition and solidification condition. The authors emphasised that the relative volume fraction, chemical composition, and structural morphology of this alloy series exert significant influence on their engineering properties. Aluminium alloy Al6063 is a member of the 6xxx group in which the prominent alloying elements are magnesium and silicon at different percentages. The distinct properties of Al6063 and other similar nonferrous alloys have been well reported to be affected by casting parameters such as mould temperature, moisture content, sand and type of binders used, pouring temperature, pouring speed, pouring height, runner size, casting size, fluidity and composition of metals among others (Li and Li, 2001;Sadrossadat and Johansson, 2009;Turbalioglu and Sun, 2011; Lus, 2012; Datau et al., 2012; Ayoola et al., 2012; Adeosun et al., 2013 ;Singh et al., 2013; Mohandass et al., 2014; Changizi et al., 2014, Souissi et al.,2014 and Kumar et al., 2016). Attempt made by Turbalioglu and Sun (2011) was based on the desire to enhance mechanical properties of AA6063 alloy using vertical continuous method. This method has been found beneficial as it provides opportunity for maximizing time and energy during billet production. This in turn reduces the overall manufacturing cost in no small measure. The authors found that high potential exists for improving the alloy’s mechanical properties at casting temperature of 690ºC and speed range of 100- 110 mm/min. Singh et al. (2013) studied the influence of pouring temperature and permeability of sand on the behavioural response of aluminium alloy. It was shown that increase in temperature and permeability of sand