Microstructural Morphology and Mechanical Properties of Cooling Slope Rheocast A380 Al Alloy

Das, P (2022) Microstructural Morphology and Mechanical Properties of Cooling Slope Rheocast A380 Al Alloy. In: Journal of Materials Engineering and Performance .

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Abstract

The present study reports microstructure and mechanical properties of A380 Al alloy, rheocast using cooling slope. The cooling slope rheocasting technique yields rosette-shaped and near-spherical primary Al (α-Al) grains, in spite of dendritic ones observed in case of conventional cast (as-received) state of the alloy. Further improvement in microstructural morphology is noticed for the said alloy, when rheocast after individual and combined addition of grain refining (Al-5Ti-1B master alloy) and modifying agents (Al-10Sr master alloy). Moreover, cooling slope rheocasting technique facilitates formation of α-type Al15(Fe,Mn)3Si2 polyhedrons within the rheocast alloy, despite highly brittle platelet-shaped β-type Al5FeSi intermetallics observed in case of conventional liquidus cast state of the alloy. Cooling slope processing also ensures uniform distribution of iron-based intermetallics (α-type Al15(Fe,Mn)3Si2 polyhedrons) within the matrix of the rheocast alloy, along with the generation of fine fibrous morphology of eutectic Si and eutectic Al2Cu particles. The above reasons govern the noticeable improvement observed in mechanical properties of the rheocast alloy compared to its conventional cast counterpart. Best set of mechanical properties, i.e., the highest tensile strength, hardness, and impact toughness, has been achieved in the combined melt-treated (grain refined + modified) rheocast alloy, among other rheocast alloys studied here. This is attributed to the minimum presence of iron-based intermetallics, finer eutectic morphology, as well as spheroidal primary Al grains, in case of refiner and modifier added rheocast alloy. © 2022, ASM International.

Item Type:	Journal Article
Publication:	Journal of Materials Engineering and Performance
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer.
Keywords:	Aluminum alloys; Binary alloys; Cast iron; Cooling; Copper alloys; Eutectics; Manganese alloys; Morphology; Refining; Silicon; Silicon alloys; Tensile strength; Titanium alloys, Al-alloy; Cooling slopes; Iron-based; Microstructural morphology; Primary al; Rheocast; Rheocast alloys; Semisolid; Spheroidal; Tensile, Intermetallics
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	14 Jan 2023 06:45
Last Modified:	14 Jan 2023 06:45
URI:	https://eprints.iisc.ac.in/id/eprint/79149

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