Mechanical properties and corrosion behaviour of fly ash particles reinforced AA 2024 composites

Abstract

Composites are most promising materials of recent interest. Metal matrix composites (MMCs) possess significantly improved properties compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Hence, composites with fly ash as reinforcement are likely to over come thecost barrier for wide spread applications in automotive and small engine applications. In the present investigation, AA 2024 alloy – 2 to 10 wt% fly ash composites were made by stir casting route. Phase identification and structural characterization was carried out on fly ash by X-ray diffraction studies. Scanning electron microscopy and optical microscopy was used for microstructure analysis. The hardness, compression and pitting corrosion tests were carried out on all these alloy and composites. The SEM studies reveal that there was a uniform distribution of fly ash particles in the matrix phase and also very good bonding is exist between the matrix and reinforcement. With increasing the amount of fly ash the density of the composites was decreased and the hardness was increased. The increase in compression strength was observed with increase in amount of fly ash. Fly ash particles lead to an enhanced pitting corrosion of the aluminium–fly ash (ALFA) composites in comparison with unreinforced matrix (AA 2024 alloy). The enhanced pitting corrosion of ALFA composites is associated with the introduction of nobler second phase of fly ash particles.

Microstructural characteristics and mechanical behaviour of aluminium hybrid composites reinforced with groundnut shell ash and B4C

“…Kumar et al [40] reported that the porosity of less than 4% is in the acceptable level. Similarly, researchers reported that while increasing the reinforcements like BLA, RHA and fly ash in the composite the density of composites decreases and the porosity increases [17,[40][41][42].…”

Influence of Heat Treatment and Reinforcements on Tensile Characteristics of Aluminium AA 5083/Silicon Carbide/Fly Ash Composites

“…Baradeswarn et al [28] carried out extensive work on the effect of reinforcements particle size on the composites and found that the compressive strength increases with an increase in wt.% of fly ash attributed to the coring and microsegregation of the particles in the matrix phase, leading to strengthening brought about by the epitaxial grain growth and interstitial bonding between the atoms. Rao et al [29] found that the composites reinforced with graphite and alumina exhibit greater compression strength, ascribed to the effect of graphite which is a ceramic reinforcement, influencing the compression characteristics of the composites due to the effect of coring on the matrix composites. Rohatgi et al [30] characterised the effect of cenospheres on AZ91D aluminium alloy and reported that the tensile properties increase with the inclusion of reinforcements in the matrix, thereby improving its metal workability characteristics for aerospace applications, thus providing an inference that the fly ash is having a limiting effect on the strength beyond 5 wt.%.…”

Mechanical properties and wear behavior of fly ash particle reinforced Al matrix composites

“…Irregular accumulation and inappropriate disposal of fly ash will lead to the global impact of pollution. Utilization of FA as a reinforcement serves as a double advantage of a suitable alternative to reduce environmental pollution and reduction of the production cost of AMCs [4][5][6][7]. Among the many techniques available to produce AMCs, stir casting is a very widely used method.…”