Fabrication and Experimental Analysis of Mechanical Properties of Aluminium (AA6063) Alloy/Eggshell Composite

Abstract

The main purpose of this study is to fabricate the metal matrix composite using carbonized eggshell powders as reinforcement and AA0663 alloy as matrix material to study the mechanical properties of composite specimens. To achieve the above purpose, stir casting method was used for development and processing of AA6063 alloy/eggshell composite. It is aimed to provide optimum stir casting process of composite thereby reduce product cost and improve mechanical properties, particularly in B and C Aluminum Company. The Taguchi method is used to design of experiment and optimize the process. Each parameter has three different levels. Taguchi method orthogonal array of L27 (3^4) is used to design this experiments. The experimental investigation was conducted under varying input influential process parameters while taking constant other stir casting parameters for resulted tensile strength and hardness test were done. The study reveals that the optimum setting values of eggshell weight percentage, stirring speed, stirring time and stirring temperature were determined as, 10 wt.%, 200 rpm, 10 minutes and 750 o C, respectively. The level of significance of each parameter was determined by the help of analysis of variance, so that eggshell weight percentage contributes 50.12 %, stirring speed 10.14 % stirring time 27.44 % and stirring temperature 8.87 % for tensile strength while eggshell weight percentage contributes 68.82 %, stirring speed 7.51 % stirring time 15.69 % and stirring temperature 3.88 % for hardness respectively. The naturally occurring eggshell material is carbonized and added to aluminum (AA6063) alloy by stir casting technique and its effects on the microstructures and mechanical properties of the composite were studied. The microstructure of the carbonized eggshell/AA6063 alloy composite was examined with the aids of optical microscopy after the specimen surface has been carefully prepared. Optical micrographs revealed that there was a homogenous distribution of eggshell particles within the aluminum (AA6063) alloy. The density of the composite also reduced significantly with an increase in the composition of the carbonized eggshell in the aluminum (AA6063) alloy. The eggshell powders can be used as reinforcement in aluminum (AA6063) alloy and its very less expensive reinforcement material. The results revealed that by the addition of carbonized eggshell particles up to 10 wt.% in AA6063 alloy, the tensile strength and hardness were increased. It was also noted that the tensile strength and hardness of the composite has decreased with the addition of the carbonized eggshell particles above 10 wt.% in the aluminum (AA6063) alloy. These results showed that the mechanical properties (tensile strength and hardness) of aluminum (AA6063) alloy are improved after the addition of carbonized eggshell powders.