Crystallization and nucleation in liquid Al containing spinel seeds Write By Reza Haghayeghi Haghayeghi, M. Qian, “Crystallization and nucleation in liquid Al containing spinel seeds”, Materials Letters, 196 (2017) 358–360. 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…
Refinement/modification of Si via self-inoculation in an Al-Si alloy Write By Reza Haghayeghi Haghayeghi, E.J. Zoqui, G. Timelli, “Refinement/modification of Si via self-inoculation in an Al-Si alloy”, Journal of Materials Processing Technology Vol.252 (2018), PP.294-303. The alloy A390 was ultrasonically treated, and the resulting material was referred to as master alloy. The master alloy…
Duplex Nucleation in AZ91 and its high temperature properties Write By Reza Haghayeghi Saber, R. Haghayeghi, H. Najafi, P. Shahbeigi-Roodposhti, “Duplex Nucleation in AZ91 and its high temperature properties”, Journal of Engineering Materials and Technology, Vol.140 (2018), PP. 041002-1 to 6 The grain refinement of Mg–Al alloy AZ91 via carbon inoculation, including the…
Write By Reza Haghayeghi : Enhanced refinement and modification via self-inoculation of Si phase in a Hyper eutectic aluminium alloy The alloy A390 was ultrasonically treated, and the resulting material was referred to as master alloy. The master alloy was added into a non-treated A390 melt over two different levels: 10 and 20% by volume in…
Write By Reza Haghayeghi : Abstract. Melt Conditioned Direct Chill (MC-DC) casting is a new development for producing high-quality billets and slabs. In the MC-DC process, liquid metal is continuously fed into a MCAST (melt conditioning by advanced shear technology) machine, where the liquid metal is subjected to high shear rate and high degree of turbulence provided by…
Write By Reza Haghayeghi : Abstract The influence of intensive shearing was studied at above liquidus temperature on solidification process of two common industrial aluminium alloys. The shearing effects on the final microstructure of AA5754 and AA7449 aluminium alloys were investigated. The result of shearing on the grain size was explored and compared with non-sheared…
Writing By Reza Haghayeghi There has been a great debate whether grain refinement is more effective when shearing above or below the liquidus. In this work, examination of the microstructural evolution in AA7075 alloy has been performed, after stirring above & below the liquidus. The results suggest that shearing above the liquidus is more effective….
Writing By Reza Haghayeghi An investigation was carried out on the grain refinement of molten AA5754 Aluminum alloy through intensive shearing. The results show intensive shearing via cavitation decreases the grain size significantly. The above hypothesis for structure refinement was evaluated and an experiment was performed to ensure the creditability of this assumption. Finally, it…
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…