Effect of Heat Transfer Rate on Different Shapes using Different Moulding Sands on Microstructural and Mechanical Properties of AA2024 by CO2 Process

Abstract

In the present study, efforts were made to replace silica sand with the other two moulding sands namely Blast furnace slag and Ferro chrome slag as silica sand was a diminishing product as the consumption increases with time as in the modern industries the rapid growth of the production of the components increases day by day. To compensate the need of industries alternative molding sands were required to meet the production requirements. To analyze the requirements needed for the modern industries observations were made on to the effects of heat transfer rate on different shapes of the castings namely cube, cylinder, circular plate and flat plate using three different molding sands (Silica sand, Blast furnace slag and Ferro chrome slag). Also, the effect of heat transfer rate on mechanical properties and micro structural behavior were studied. Out of these two patterns were single piece patterns namely flat plate and circular plate and another two were split piece patterns namely cube and cylinder. Here the interesting fact is the single piece patterns were dissipating more amount of heat than the split piece patterns in spite of its contact area. Flat plate was showing the faster heat dissipation rate than in all other components which was also supported by the micro hardness study, which reveals that higher micro hardness was observed at the flat plate component of ferro chrome slag mould with 153.6 Hv and lowest was observed at the cylinder component of Blast furnace slag mould with 109.9 Hv. Microstructural results revealed that the cooling rates plays a major role in the castings of different shapes. It was revealed that fine grain structure was observed at ferro chrome slag components as the heat dissipating capacity of the Ferro chrome slag was high. Also, the finer structure was observed at single piece patterns which were also supported by heat transfer rate graphs and micro hardness results. Hence, the present study focusing on the best suitable shape and replacement of the silica sand with other two molding sands by Co2 process.