Microstructural Evaluation and Corrosion Resistance of Semisolid Cast A356 Alloy Processed by Equal Channel Angular Pressing

• Published in: Metals (Basel ) Vol. 9; no. 3; p. 303
• Main Authors: Gebril, Mohamed Abdelgawad, Omar, Mohd Zaidi, Mohamed, Intan Fadhlina, Othman, Norinsan Kamil
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 08-03-2019
• Subjects: A356 alloy; Alloys; Aluminum base alloys; Casting; Casting alloys; Cooling; cooling slope; Corrosion resistance; Corrosion resistant alloys; Corrosion tests; ECAP; Electrodes; Equal channel angular pressing; Grain refinement; Grain size; hardness; Heat treatment; Mechanical properties; Morphology; pitting corrosion; Room temperature; Semisolids; Stainless steel; Germany
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met9030303

As-cast and semisolid casting using a cooling slope A356 alloy were processed by equal channel angular pressing (ECAP) for Si and grain refinement. The ECAP was conducted at room temperature in a mold, with a channel angle of 120°, and this resulted in a significant size reduction of grain and Si particles from 170.5 and 4.22 to 23.12 and 0.71 µm, respectively, after six passes of heat-treated cooling slope casting, using the ECAP process. The hardness increased with ECAP processing, from 61 HV, for the as-cast alloy, to 134 Hv, after six passes of heat-treated cooling slope casting. The corrosion resistance of the alloy improved, from 0.042 to 0.0012 mmy−1, after the ECAP process. In this work both the strength and corrosion resistance of the ECAPed A356 alloys were improved with the application of the cooling slope process than without (i.e., from the as-cast condition).