Effect of Sr–Grain Refining–Si Interactions on the Microstructural Characteristics of Al–Si Hypoeutectic Alloys

Tahiri, Hicham; Mohamed, S. S.; Doty, H. W.; Valtierra, S.; Samuel, F. H.

doi:10.1007/s40962-017-0169-0

Cited by 21 publications

(10 citation statements)

References 13 publications

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“…It has been reported that Ti 2 A1 20 RE can not exist stably in the aluminum alloy melt [19,20], it will dissolve and provide a lot of RE for the aluminum melt [21]. A large number of research reports have confirmed that RE has a good modification effect on eutectic Si by forming nano rare earth phase [22] or inhibiting Si twin growth [23]. Therefore, it can be seen from table 2 that as the addition of Al-5Ti-0.62C-1.07La master alloy increases, more and more TiC, Al 3 Ti and Ti 2 A1 20 La will be contained in A356 alloy melt.…”

Section: Resultsmentioning

confidence: 99%

Effects of Al-5Ti-0.62C-1.07La intermediate alloy on the microstructure and mechanical properties of A356 aluminum alloy

Ding

Zhang

et al. 2020

Mater. Res. Express

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The physical characters that belong to hypo-eutectic Al-Si alloys are affected by certain important factors including the dimension, distribution together with structure of eutectic Si crystals together with primary α-Al. In this paper, A356-x Al-5Ti-0.62C-1.07La (x=0, 4, 5, 6, 7 wt%) alloys are was prepared by mechanical stirring. The effects of Al-5Ti-0.62C-1.07La intermediate alloy on the microstructures and mechanical properties of A356 alloy are investigated. Results show that the primary α-Al was significantly refined by Al-5Ti-0.62C-1.07La intermediate alloy. The secondary dendrite arm space (SDAS) of unrefined α-Al is approximately 40 μm. When the substance of Al-5Ti-0.62C-1.07La intermediate alloy is 6 wt%, SDAS declines to 10 μm. In addition, the component part of eutectic Si turns from thick acicular/schistose to short rod-like together with a section of pellets. Adding 6 wt% Al-5Ti-0.62C-1.07La intermediate alloy, A356-T6 alloy obtained the best tensile function and hardness. The ultimate tensile strength (UTS), elongation (El) together with Vickers hardness (HV) are 183.5 MPa, 8.2% and 62.3, which is increased by 30.3%, 95.2% and 38.1%, respectively. Furthermore, the variation in mechanical properties change with the development of micro-structure.

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Section: Resultsmentioning

confidence: 99%

Effects of Al-5Ti-0.62C-1.07La intermediate alloy on the microstructure and mechanical properties of A356 aluminum alloy

Ding

Zhang

et al. 2020

Mater. Res. Express

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“…Although increasing the amount of added grain refiner from 0.057%Ti in alloy R to 0.22% in alloy RGM noticeably reduced the grain size, the increase in added Al-5%Ti-1%B to alloy RGM resulted in the precipitation of massive platelets of (Al,Si) 3 Ti which would have a negative effect on the alloy mechanical properties. It is inferred from the work of Tahiri et al [16] that the appropriate amount of added grain size should be about 0.14% (almost halfway between Ti in alloy R and alloy RGM as shown in Figure 3e). The morphology of eutectic Si plays a vital role in determining the mechanical properties of Al-Si alloys.…”

Section: Grain Refining and Modificationmentioning

confidence: 96%

“…In the light of the above, the effects of the addition of melt treatment and alloying elements on the microstructure, hardness and tensile properties of the 396 alloy were studied. According to Tahiri et al [16,17] increasing the added grain refiner beyond 0.14% Ti using Al-5%Ti-1%B master alloy would lead to an increase in both grain size, and the amount of decomposed Al 3 Ti (or more precisely (Al,Si) 3 Ti platelets) would result in marked deterioration in the alloy mechanical properties.…”

Section: Grain Refining and Modificationmentioning

confidence: 99%

“…The modified structure is often improperly called globular [16,17] since the fibers appear to be small individual globules (particles) on a conventionally polished surface; they are, in fact, connected in a coral or seaweed-like structure. Figures 4a and 5a clearly show the microstructural differences between the unmodified and modified alloys, respectively.…”

Section: Grain Refining and Modificationmentioning

confidence: 99%

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Intermetallics Formation during Solidification of Al-Si-Cu-Mg Cast Alloys

et al. 2022

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The present study was undertaken to examine the effect of iron, manganese, copper and magnesium on the microstructural characteristics of Al-11%Si-2%Cu-Mg-based alloy referred to as 396 under different working conditions. The results show that strontium (Sr) has high affinity to react with magnesium (Mg), resulting in reduced effectiveness as eutectic silicon modifier or age hardening agent. In addition, Sr alters the sequence of the precipitation of the α-AlFeMnSi phase from post-eutectic to pro-eutectic which would hardens the soft α-Aluminum matrix. The mechanism is still under investigation. The interactions between iron (Fe) and Mg and Sr-Mg result in the formation of serval dissolvable intermetallics during the solutionizing treatment such as β-AlFeSi, π-AlFeMgSi and Q-AlMgSiCu phases. The study also emphasizes the role of modification and grain refining as well as intermetallics in porosity formation and hardness of samples aged in the temperature range 155–240 °C.

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“…Because molten Al4Si2Sr contained a considerable amount of Sr, the Si structure was sufficiently refined, i.e., Si did not precipitate as crystals and was refined on the boundary surface of the crystal, indicating that modification of the structure was successful [23,24]. The addition of Sr to molten alloy to form Al 2 Si 2 Sr resulted in the formation of a refined Si crystal [25]. However, the Sr that was bound during this reaction might have separated at the top of the molten metal or oxidized to SrO and disappeared naturally.…”

Section: Refinement Of the Si Structure In The Ac4ch Alloymentioning

confidence: 99%

Optimization Studies of AC4CH Material in the Cylinder Block of a Diesel Engine Application

2020

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The reduction of the weight of the engine of a vessel or an automobile can result in improved engine efficiency and lower CO2 emissions. Therefore, this study was conducted to improve the mechanical properties of the AC4CH alloy, an alternative to cast iron for engine fabrication, through the addition of Si and Mg to aluminum. The mechanical properties of the alloy were improved through refinement of the Si structure, grain refinement, and heat treatment. In addition, the applicability of a cylinder block fabricated with the modified AC4CH alloy to a diesel engine was validated through a 300 h durability test.

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Effect of Sr–Grain Refining–Si Interactions on the Microstructural Characteristics of Al–Si Hypoeutectic Alloys

Cited by 21 publications

References 13 publications

Effects of Al-5Ti-0.62C-1.07La intermediate alloy on the microstructure and mechanical properties of A356 aluminum alloy

Effects of Al-5Ti-0.62C-1.07La intermediate alloy on the microstructure and mechanical properties of A356 aluminum alloy

Intermetallics Formation during Solidification of Al-Si-Cu-Mg Cast Alloys

Optimization Studies of AC4CH Material in the Cylinder Block of a Diesel Engine Application

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