Writing By Reza Haghayeghi : Abstract : Conventional Grain Refinement is Performed Through the addition of chemical refiners. However, This article proposes physical refinement as an alternative method for producing fine grain size. Two methods of physical refinement are examined and evaluated, namely Melt Conditioning by Advanced Shear Technology (MCAST) and the use of an…
Writing By Reza Haghayeghi Step-by-step in situ near-atomic-resolution observations were presented for initial crystallization or nucleation in a liquid Al-10Mg (wt%) alloy containing spinel (MgAl2O4) seeds. Ordering of Al atoms was observed in the alloy at the interface with spinel at the superheat of 73 _C or at the melt temperature of 680 _C, where…
Writing By Reza Haghayeghi: The influence of intensive shearing above liquidus on the Solidification Process, microstructural evolution and its effect on the final Microstructure for the Al–10 wt% Mg alloy were investigated and discussed thor- oughly. The effect of shearing was explored and was compared with non-sheared samples. The effects of relaxation (holding melt after…
Reza Haghayeghi Abstract: The effects of ultrasonic treatment (UT) and electromagnetic stirring (EMS) forces, individually and in combination, prior to high pressure die-casting of AA5754 alloy were assessed. The liquid of alloy was subjected to UT, EMS and the combined style and then transferred to the shot chamber. The grain size, mechanical properties, gas content…
Writing By Reza Haghayeghi : The effects of introducing ultrasonic vibrations prior to high pressure die casting have been experi- mentally investigated. Results suggest reductions of up to 73% in grain size and up to 5% on porosity levels due to cavitation, leading to enhanced structural performance. The typical values of ultimate tensile stress…
Writing By Reza Haghayeghi : Twin screw melt conditioners are used for mixing purposes and are mainly used for polymer processing. These conditioners (extruders) can be used for liquid metal processing in which liquid metal/slurry is subjected to high shear stress. This process results in grain refinement of structure. In this article, in a co-rotating twin…
Reza Haghayeghi Abstract: The effects of ultrasonic treatment (UT) and electromagnetic stirring (EMS) forces, Individually and in combination, Prior to high pressure die-casting of AA5754 alloy were assessed. The liquid of alloy was subjected to UT, EMS and the combined style and then transferred to the shot chamber. The grain size, Mechanical properties, Gas content…
© 2016 Elsevier Inc. All rights by Reza Haghayeghi In thixoforming processes control of the solid-to-liquid transition and grain size of the mush metal is essential. If eutectic melting is avoided, subsequent melting of the primary phase should be controllable. To achieve this, the sensitivity of the liquid fraction, dfL/dT, at the desired liquid fraction,…