Experimental and CFD investigation on the solidification

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. The outcomes indicate that at temperatures below the liquidus, the convective forces produced by electromagnetic forces cannot break the dendrites due to low velocities, whilst at shearing above the liquidus through a cavitation-enhanced nucleation mechanism grain refinement is promoted. It appears that by applying magnetic forces above the liquidus temperature, shearing effects result in finer grain sizes and consequent enhancement of properties. Keywords: Electromagnetic Casting, Grain Refinement, Cavitation Mechanism   Experimental and CFD investigation on the solidification...ادامه مطلب

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 samples. The physical refining that was provided by Melt Conditioner was established. Experimental achievements suggest that shearing above liquidus can be used as an alteative for refining the microstructure of Al alloys.   Experimental and CFD investigation on the solidification...ادامه مطلب

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 order to investigate its potency for silicon refinement. Appropriate refinement of primary silicon crystals is obtained by the addition of master alloy. The addition leads to significant formation of twins and stacking faults where the former produces branching and the latter contributes to growth retard providing ∼10 μm Si primary particles.Minor eutectic Si modification is established by the Si clusters which are provided by the master alloy. By master alloy addition, roundness and aspect ratio of eutectic silicon were enhanced and the tensile properties as well as the wear resistance were improved. The morphological evolution, as well as the mechanisms involved in the primary Si refinement and eutectic modification are defined and discussed. Keyword : Al-Si alloysCastingSolidificationMaster alloySi refinement Experimental and CFD investigation on the solidification...ادامه مطلب

Reza HaghayeghiAn investigation on grain refinement of Al alloys through liquid shearingA Comparison of Grain Refinement Efficiency by Shearing above and below the LiquidusInitial Crystallisation or Nucleation in a Liquid Aluminium By Reza HaghayeghiAn Investigation on Physical and Chemical Refinement of Aerospace By Reza HaghayeghiNumerical and Experimental Investigation of the Grain RefinementTh Experimental and CFD investigation on the solidification...ادامه مطلب

I am a well-trained metallurgist who has an extensive experience in the field processing metallurgy particularly Solidification and Casting. As an inquisitive and enthusiastic person, I am interested to work on the research area of Materials Engineering and it’s the related phenomena to improve the Experimental and CFD investigation on the solidification...ادامه مطلب

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 Experimental and CFD investigation on the solidification...ادامه مطلب

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 Experimental and CFD investigation on the solidification...ادامه مطلب