Experimental Investigation on Abrasive Wear Behavior of Functionally Graded Aluminum Composite

Abstract

Functionally graded Al–Si12Cu/10 wt.% B4Cp metal matrix composite (MMC) has been fabricated under stir casting process followed by horizontal centrifugal casting method. The casting of length 170 mm, outer diameter 160 mm, and thickness 16 mm was obtained under the centrifugal speed of 1000 rev min−1. The microstructural evaluation was carried out on the surfaces at distance of 3, 6, 9, and 11 mm from the outer periphery of the casting to ensure the distribution of reinforcement particles, and the surfaces at same distance were tested for its hardness using microhardness tester. The microstructural results revealed that surface at a distance of 3 mm from the outer periphery has reinforcement concentration of 32% and surface at a distance of 11 mm has reinforcement concentration of 3%. The hardness of the surface was improved considerably according to the reinforcement concentration. The three-body abrasive wear test was conducted on the composite specimens as per L16 orthogonal array for parameters such as the load, speed, time, and reinforcement concentration. Each parameter was varied for four levels and the optimum level of each parameter was found out through signal-to-noise ratio analysis using “smaller-the-better” characteristics. The signal-to-noise ratio analysis revealed that load was the dominant parameter on the abrasive wear behavior followed by reinforcement concentration, speed, and time. The analysis of variance (ANOVA) result indicates the parameter that affects the response significantly and results were agreed with signal-to-noise ratio analysis. The regression equation was developed and results were validated using confirmation experiments. The worn-out surfaces were examined using scanning electron microscope (SEM) for observing the wear mechanism.

Abrasive wear behavior of monolithic alloy, homogeneous and functionally graded aluminum (LM25/AlN and LM25/SiO2) composites

“…The load of 64 N at the interfaces produces crushing of the sand particles at the stage of initial contact with it and thereby the sand particles are effective in abrade the surface of the specimen which leads to more material removal. The further increase in load to 80 N makes greater crushing effect on the abrasive medium and therefore the sand particles gets reduce in their sizes, where the same behaviour is observed (Antonov et al 2012;Radhika and Raghu 2015). Thus, the compression of these downsized abrasive medium outcomes in more cutting and abrading action which increases the abrasion wear rate.…”

Studies on Mechanical Behaviour of Aluminium/Nickel Coated Silicon Carbide Reinforced Functionally Graded Composite

“…The centrifugal force allows more number of high density nickel coated SiC particles to be dispersed to the outer periphery. With the increased uniform distribution and high volume fraction of SiC particles, the hardness near the outer periphery was more and similar phenomenon was studied here [19,20]. The solidification occurred from outer periphery towards inner periphery of casting, while the pressure force acts from inner to outer in an opposing radial direction producing a squeeze effect.…”

Fabrication of LM 25/WC functionally graded composite for automotive applications and investigation of its mechanical and wear properties

“…Low hardness at inner surface is due to the presence of microporosities and fewer reinforcement particles causing the indenter to produce increased deformation on the surface. Hence, it is concluded that the varying concentration of reinforcement particles defines the hardness and gradient properties along the radial direction of the casting [19,20].…”