Author : Shivaprakash.Y.M, K.V.Sreenivasa Prasad and Yadavalli Basavaraj

Of the many different types of particulate reinforcements tried out in the recent times for producing composite, fly ash is the cheapest and abundantly available waste by product from the combustion plants. Keeping in mind the environmental hazards of fly ash it has been used for producing composites besides for brick and cement manufacturing. Generally the physical and chemical nature of fly ash varies depending upon source. In the present investigation, precipitator type fly ash having particle size below 45 μm is collected from JSW steels, Bellary, Karnataka, India at atmospheric temperature and composite were produced by reinforcing it in the wrought aluminium alloy AA2024.The motorized stir casting setup has been employed to fabricate the composite samples containing 2.5, 5, 7.5, 10 and 15 % by weight of fly ash. Solutionizing is carried out on AA2024+10 composite at a temperature of 350,450 and 530oC for same duration of 90 minutes followed by quenching in air (37oC) and water media (25oC). Artificial aging is carried out at 175oC for 60 minutes.The non-heat treated and heat treated AA2024+10% fly ash composite samples were tested for dry sliding wear behaviour in pin-on-disc machine. For each specimen the wear test is conducted at constant speed of 200 rpm (0.628 m/sec velocity) and by applying different normal loads like 10, 25 and 35 N in the laboratory conditions. For determining the wear mechanism of composite, the worn surfaces were examined using Inverted metallurgical microscope. Experimental results indicated a good improvement in the wear characteristics due to heat treatment. Artificially aged specimens in specific showed superior wear performance than the other.

Keywords: stir casting, fly ash composite, pin-on-disc machine, dry sliding wear, heat treatment

Article published in International Journal of Current  Engineering  and Technology, Vol.3,No.3(Aug- 2013)