Effects of cold severe plastic deformation and heating on dendritic and non-dendritic structures: A356 alloy. (October 2014)

• Record Type: Journal Article
• Authors: Dodangeh, A.; Kazeminezhad, M.; Aashuri, H.
• Is Part Of: International journal of cast metals research. Volume 27:Number 5(2014)
• Page Start: 312
• Page End: 320
• Publication Date: 2014-10
• Subjects: Metal castings -- Periodicals; Founding -- Periodicals; Foundry research -- Periodicals; Foundry chemistry -- Periodicals; 671.2
• DOI: 10.1179/1743133614Y.0000000116
• Languages: English
• ISSNs: 1364-0461

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>In this research the effects of cold deformation and heating to the semi-solid temperature on microstructure and mechanical properties of cast dendritic and non-dendritic structures of A356 alloy were investigated. To produce the non-dendritic samples, the semi-solid slurry was obtained by electromagnetic stirring and rheoforged and then the samples were heated to semi-solid temperature. In order to impose the deformation to the dendritic and non-dendritic samples, multidirectional forging process was used. Non-dendritic samples were deformed with applying one to three passes of the multidirectional forging and then were kept at the semi-solid range of temperature again. Microstructural and mechanical properties of the deformed samples after and before heating were investigated. The dendritic structure after one pass of the multidirectional forging was kept at the semi-solid temperature to reach a different non-dendritic structure by strain induced melt activation process. Micro and macro hardness tests were used to study the mechanical properties of these samples. For metallographic examinations, scanning electron microscopy and the optical microscope equipped with the Clemex image analyzer software were used. The circular diameter of the heated rheoforged samples to semi-solid temperature that deformed to one pass of the multidirectional forging and then kept at semi-solid state was smaller than that of ones deformed to two and three passes and kept at semi-solid state. From the results achieved for the strain induced melt activation sample, it was obvious that this is an effective process to produce non-dendritic structure with approximately the same sphericity and lower globule size compared with other studied samples.</p> </abstract>