Table 1.
Chemical composition of Al-Si7Mg (LM25) alloy.
Fig 1.
(a) Schematic diagram of the permanent steel mould design welded with a metal plate for electromagnetic agitation; (b) Photograph of the actual EN19 steel mould used for casting the Al-Si7Mg alloy samples.
Fig 15. Variation of wear rate versus load for various voltages applied with refiner addition.
Table 2.
Specifications of coil assembly.
Fig 2.
Nomenclature of EMF coil assembly.
Fig 3.
EMF coil with a stand.
Fig 4.
Schematic of the electromagnetic agitation setup and stepwise solidification process for Al-Si7Mg alloy treatment.
(a) Hardware Setup Schematic (Panel A). (b) Stepwise Process Flowchart.
Fig 5.
Oil-fired diesel furnace of the pit type for alloy melting.
Table 3.
Details of samples cast with grain refiners and varying (EMF) to the melt.
Fig 6.
Tensile test specimen.
Fig 7.
Hardness test samples.
Fig 8.
The optical micrograph of the specimens that are subjected to an electromagnetic field (EMF) at 220V.
It is evident that the size of the grains has decreased, and a close grain is visible in the image. Al-Si-alloy microstructures are made up of an aluminium matrix reinforced by Si precipitates, as well as a mixture of Fe-rich intermetallic and eutectic silicon particles. Micrograph of specimens subjected to an electromagnetic field (EMF) at 50V shows that, with the use of a refiner (AL-10%Ti), the grain size is reduced and a close grain structure is observed. (a) sample subjected to EMF at 50Volts. (b) with refiner (Al-10%Ti) subjected to EMF at 50Volts. The optical micrograph of the specimens that are subjected to an electromagnetic field (EMF) at 100V, the size of the grain is decreased, and the grain is noted to be close together. It is evident from the optical micrograph of the specimens exposed to an electromagnetic field (EMF) at 100 volts that the refiner (AL-10%Ti) reduces grain size and produces a close-grained structure. (c) subjected to EMF at 100Volts. (d) with refiner (Al-10%Ti) subjected to EMF at 100Volts. Optical micrograph of specimens subjected to an electromagnetic field (EMF) at 120V, with a refiner (AL-10%Ti). The grain size decreases, and close grains can be observed. (e) subjected to EMF at 120Volts. (f) with refiner (Al-10%Ti) subjected to EMF at 120Volts. The optical micrograph of specimens subjected to an electromagnetic field (EMF) at 140V shows that, with the refiner (AL-10%Ti), the grain size is reduced and a close grain structure is observed. (g) subjected to EMF at 140Volts. (h) with refiner (Al-10%Ti) subjected to EMF at 140Volts. The optical micrograph of specimens subjected to an electromagnetic field (EMF) at 160V shows that, with the refiner (AL-10%Ti), the size of the grains is decreased, and a close grain structure is visible in the image. (i) subjected to EMF at 160Volts. (j) with refiner (Al-10%Ti) subjected to EMF at 160Volts. The optical micrograph of the specimens that are subjected to an electromagnetic field (EMF) at 180V. It can be observed that there is a decrease in grain size and a tight grain structure. (k) subjected to EMF at 180Volts. (l) with refiner (Al-10%Ti) subjected to EMF at 180Volts. The optical micrograph of the specimens that are subjected to an electromagnetic field (EMF) at 200V. There is a decrease in grain size, accompanied by a tight grain structure. (m) subjected to EMF at 200Volts. (n) with refiner (Al-10%Ti) subjected to EMF at 200Volts. (o) subjected to EMF at 220Volts. (p) with refiner (Al-10%Ti) subjected to EMF at 220Volts.
Fig 9.
Variation of ultimate tensile strength (UTS) with applied electromagnetic field (EMF) voltage for Al-Si7Mg alloy without grain refiner.
The peak at ~120V indicates an optimal agitation intensity for grain refinement, beyond which strength decreases due to increased defect formation.
Fig 10.
Variation of ultimate tensile strength (UTS) with applied electromagnetic field (EMF) voltage for Al-Si7Mg alloy with Al-10%Ti grain refiner.
The sustained increase up to 220V demonstrates the synergistic effect, where EMF agitation optimizes the distribution and potency of refiner particles, leading to progressive grain refinement.
Fig 11.
Comparison of Tensile strength values for Al-Si7Mg alloy with and without the addition of refiner.
Fig 12.
BHN values for different EMF.
Fig 13.
BHN values for various EMF applied in volts for Al-Si7Mg with refiner.
Fig 14.
Variation of wear rate versus load for various voltages applied without refiner addition.
Fig 15.
Variation of wear rate versus load for various voltages applied with refiner addition.