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Microstructural modification of Al–30Si–5Fe Alloy using a combination of rapid solidification and thixoforming processes
, Article Metallography, Microstructure, and Analysis ; Volume 5, Issue 3 , 2016 , Pages 217-228 ; 21929262 (ISSN) ; Aashuri, H ; Ferasat, K ; Nikzad, S ; Sharif University of Technology
Springer New York LLC
Abstract
It is commonly known that the properties of materials are strongly related to their microstructure. This paper introduces a method that is a combination of rapid solidification (melt spinning) and semisolid forming (thixoforming) processes, which are used to refine the microstructure of “as-cast” Al–30Si–5Fe alloy and improve its mechanical properties. Produced Al–30Si–5Fe ribbons by melt-spinning process, were pulverized and subsequently consolidated at 300 °C in argon atmosphere. Prepared specimens were thixoformed at temperatures ranging from 580 to 700 °C in various holding times. Some samples were also directly thixoformed from as-cast condition. Microstructure of the as-cast, meltspun,...
Mechanical properties of Al–30Si–5Fe alloy using combination of rapid solidification and thixoforming processes
, Article Metallography, Microstructure, and Analysis ; Volume 6, Issue 6 , 2017 , Pages 502-511 ; 21929262 (ISSN) ; Aashuri, H ; Nikzad, S ; Ferasat, K ; Sharif University of Technology
Abstract
In this study, a combination of rapid solidification (melt-spinning) and semisolid forming (thixoforming) processes was used to refine the coarse microstructure of “as-cast” Al–30Si–5Fe alloy and improve its mechanical properties. Al–30Si–5Fe ribbons produced by the melt-spinning process were pulverized and subsequently consolidated at 300 °C in an argon atmosphere. Prepared specimens were thixoformed at temperatures ranging from 580 to 700 °C for various holding times. Some cast samples were also directly thixoformed as reference. In all thixoformed samples, microstructures were modified and needle-like intermetallic compounds as well as silicon particles in the as-cast part were changed...
The Effect of Temperature and Rotational Speed on Structure and Mechanical Properties of Cast Cu Base Alloy (Cu-Al-Si-Fe) Welded by Semisolid Stir Joining Method
, Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 46, Issue 12 , 2015 , Pages 5782-5788 ; 10735623 (ISSN) ; Aashuri, H ; Kokabi, A. H ; Shafizadeh, M ; Nikzad, S ; Sharif University of Technology
Abstract
Semisolid stir joining has been under deliberation as a possible method for joining of copper alloys. In this study, the effect of temperature and rotational speed of stirrer on macrostructure evaluation and mechanical properties of samples were investigated. Optical microscopy and X-ray diffraction were performed for macro and microstructural analysis. A uniform micro-hardness profile was attained by semisolid stir joining method. The ultimate shear strength and bending strength of welded samples were improved in comparison with the cast sample. There is also lower area porosity in welded samples than the cast metal. The mechanical properties were improved by increasing temperature and...