In the present scenario, composites are in huge demand in the industries due to their light weight, wear resistance, stiffness and high strength. The functional and structural properties were improved according to the need of industry. Particulate reinforcement is one of the methods to enhance the strength, ductility and toughness of the composites. Stir casting or friction stir processing technique was used to fabricate the metal matrix composite. For technology seekers it is very difficult to select appropriate techniques because there is lack of bench mark standards and industry experiences. The novel contribution of this paper is to provide systematic approaches and methodology which enable academic user as well as industry persons to select appropriate method and parameters for the fabrication of the metal matrix composite. This study guides the new researchers to fabricate and characterize the mechanical properties of aluminium-based composites reinforced with Al2O3, B4C, SiC, TiC, graphite and TiB2 particles.

The effect of various wire electrical discharge machining process parameters such as pulse on time, pulse off time, pulse current and the wire drum speed on machined surface quality characteristics such as surface roughness and kerf width has been discussed. The experiments were carried out with L27 orthogonal array on hybrid metal matrix composite prepared by inert gas–assisted electromagnetic stir casting process using particulates 7.5% Al2O3 and 7.5% SiC each in Al7075 alloy. Taguchi-based grey relational analysis, a multi-response optimization technique, was used to find the optimal process parameter setting for the best quality machined characteristics. Results of analysis of variance showed that the order of significance was pulse on time, pulse current, pulse off time and the wire drum speed contributing 50.02%, 39.50%, 4.58% and 2.75%, respectively, while machining the hybrid composite. Confirmation test was carried out at selected optimal parameter setting, which showed improvement in grey relational grade, thus confirming the robustness of grey relational analysis.

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The friction stir welding is a pioneering solid-state metal joining technique for producing high-quality joints in materials. In this article, Taguchi approach is applied to analyze the optimal process parameters for optimum tensile strength and hardness of welded dissimilar A6061 and A6082 alloys. An orthogonal array of L9 is implemented and the analysis of variance is employed to investigate the importance of parameters on responses. The experimental tests, conducted according to combination of rotational speed, tool tilt and types of tool pin profile parameters. The results indicate that the rotational speed is most significant process parameter that has the highest influence on tensile strength and hardness, followed by tool pin profile and tool tilt. The optimum results verified by conducting confirmation experiments. The predicted optimal value of tensile strength and hardness of dissimilar joints produced by friction stir welding are 267.74 MPa and 80.55 HRB, respectively.

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A6061/10% SiC composite has been fabricated by mechanical stir casting process. Fabricated composite has also been characterized through optical microscopy, X-ray diffraction analysis (XRD), scanning electron microscopy analysis (SEM) with energy dispersive X-ray techniques (EDX), and thermogravimetric/differential thermal analysis (TG/DTA). The composite has been experimentally investigated for its machinability usingZ-axis numerically controlled (ZNC) electrodischarge machining (EDM) process. The effects of the four process parameters, namely, current, gap voltage, pulse-on time, and pulse-off time are investigated on material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) by varying one parameter at a time approach. Optical microscopy and SEM analysis revealed the uniform distribution of SiC particles in aluminum matrix phase. XRD investigation corroborated the elemental composition of 6061 Al alloy and reinforcement particles. Thermal analysis shows stability of composite upto 650°C. The machinability characteristics, namely, MRR, TWR, and SR have been interpreted using graphical representations. The study indicates that all the machining parameters affect the machining performance of A6061/10% SiC composite. Optimum machining performance has been realized at the lower setting of current and pulse-on time and the optimum setting of pulse-off time and gap voltage.

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