Effect of micro graphite particles on the microstructure and mechanical behavior of aluminium 6061 (Al-Mg-Si) alloy composites developed by novel two step casting technique

Abstract

In the present research, the effect of micron sized graphite addition on the microstructure and tensile failure of Al6061 alloy has been studied. The Al6061 alloy metal matrix composites reinforced with 6, 9 and 12 varying weight percentages of graphite particles were fabricated by novel two step stir cast route which helps in improving the wettability of Al6061 alloy matrix with graphite particles. The synthesized composites were subjected to microstructural studies, density, hardness and tensile properties testing. Microstructural characterizations of obtained samples were carried out by SEM microscopy, EDS and XRD patterns. The occurrence of graphite particles were confirmed by the XRD patterns. The density and hardness of metal composites have been decreased with adding of graphite reinforcement, while the ultimate tensile strength and yield strengths were improved with the addition of graphite particles. There was increase in the elongation of the Al6061 alloy composite after the incorporation of the reinforcement. Various fracture mechanisms were observed in the Al6061-graphite composites using SEM.

Preparation and investigation of mechanical behavior and characterization of AA7475/ZrO2/Gr hybrid MMC

“…The hybrid composites have visible zirconium and carbon peaks. The intensity of the carbon peaks increases as the graphite concentration increases [11,13]. The spectrum shows the existence of aluminum as the highest element, followed by zinc and various alloying elements.…”

“…The reinforcement particulates influence the mechanical properties, thermal properties, wear rate, and corrosion. Nagaral M et al [11] suggested a new two-step casting method for making aluminum 6061 (Al-Mg-Si) alloy composites with different amounts of tiny graphite particles that change the microstructure and mechanical behavior. Kumar R A et al [12] conducted a review on the fabrication and corrosion behavior of aluminium metal matrix composites.…”

Influence of Graphite Particles on the Mechanical and Wear Characterization of Al6082 Alloy Composites

“…Liquid metallurgy processes, including pressure infiltration, stir casting, spray deposition, and in situ processing, are the most cost-effective ways to manufacture MMCs. Advantages of melt stirring over other processes include the increased output for near net shaped components, greater flexibility in terms of material choice, enhanced matrix particle bonding, and granular control over the matrix structure. − Poor wettability and uneven reinforcement distribution are two problems that arise when stir casting aluminium metal matrix composites (AMCs). There are a number of methods for increasing wettability, such as the addition of halide salts, mechanical stirring, preheating the reinforcement particles to remove the absorbed gases from the particle surface, adding alloying elements like magnesium, zirconium, and silicon nitride, using surface coatings on reinforcement particles, etc. , …”

Evaluation of mechanical behaviour and tensile failure analysis of 8 wt.% of nano B4C particles reinforced Al2214 alloy nano composites

“…Aluminum metal matrix composites (AMMC) properties can be enhanced by selecting the appropriate reinforcing geometry, type, and shape, as well as the appropriate fabrication procedure [6,7]. The addition of hard and stronger ceramic particles to a medium-strength, ductile, and low-stiffness metal matrix can improve the properties of the ceramic and the base matrix [8,9]. The qualities of MMCs are largely determined by the processing method used.…”