Effects of La and Ce Addition on the Modification of Al-Si Based Alloys

Elgallad, E. M.; Doty, H. W.; Alkahtani, Saleh A.; Samuel, F. H.

doi:10.1155/2016/5027243

Cited by 34 publications

(12 citation statements)

References 21 publications

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“…RE-treated alloys can maintain the modified structure much longer than Na-treated alloys. A reliable and persistent eutectic modification effect can be obtained with rare earth addition [2][3][4][5][6]. However, the minimum amount of rare earths necessary to obtain proper modification is exceptionally large.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rare Earth Metals, Sr, and Ti Addition on the Microstructural Characterization of A413.1 Alloy

Mahmoud

Samuel

Doty

et al. 2017

Advances in Materials Science and Engineering

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The present work was performed on A413.1 alloy containing 0.2-1.5 wt% rare earth metals (lanthanum or cerium), 0.05-0.15% Ti, and 0-0.02 wt% Sr. These elements were either added individually or combined. Thermal analysis, image analysis, and electron probe microanalysis were the main techniques employed in the present study. The results show that the use of the depression in the eutectic temperature as a function of alloy modification cannot be applied in the case when the alloy is treated with rare earth metals. Increasing the concentration of RE increases the solidification zone especially in Sr-modified alloys leading to poor feeding ability. This observation is more prominent in the case of Ce addition. Depending upon the amount of added Ti, two RE based intermetallics can be formed: (i) a white phase, mainly platelet-like (approximately 2.5 m thick), that is rich in RE, Si, Cu, and Al and (ii) a second phase made up of mainly grey sludge particles (star-like) branching in different directions. The grey phase is rich in Ti with some RE (almost 20% of that in the white phase) with traces of Si and Cu. There is a strong interaction between RE and Sr leading to a reduction in the efficiency of Sr as a eutectic Si modifier causing particle demodification.

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Section: Introductionmentioning

confidence: 99%

Effect of Rare Earth Metals, Sr, and Ti Addition on the Microstructural Characterization of A413.1 Alloy

Mahmoud

Samuel

Doty

et al. 2017

Advances in Materials Science and Engineering

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“…The enrichment of Ce elements at the frontiers of the solid-liquid interface also decreased the diffusion rate of Mg and Si atoms from α-Al lattice to the liquid phase, thereby reducing the efficiency of solute redistribution [21]. Thus, the nucleation and growth of Mg 2 Si in the 5182 Al alloy was retarded, which caused the breakage of the Mg 2 Si network in the 5182-0.4Ce Al alloy (Figure 5a,b).…”

Section: Effect Of Ce-rich Mischmetal On Microstructure Evolutionmentioning

confidence: 99%

Effects of Ce-Rich Mischmetal on Microstructure Evolution and Mechanical Properties of 5182 Aluminum Alloy

et al. 2019

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This paper addresses the effects of Ce-rich mischmetal on the microstructure evolution of a 5182 aluminum alloy during annealing and rolling processes. The Ce-rich mischmetal was added to an as-cast 5182 aluminum alloy in an induction furnace, and this was followed by homogenized annealing at 450 °C for 24 h and a rolling operation. The microstructure evolution and mechanical properties’ analysis of the 5182 Al alloy were characterized. The results show that the Ce-rich mischmetal could modify the microstructure, refine the α-Al grains, break the network distribution of Mg2Si phases, and prevent Cr and Si atoms from diffusing into the Al6(Mn, Fe) phase in the as-cast 5182 Al alloys. Ce-rich mischmetal elements were also found to refine the Al6(Mn, Fe) phase after cold rolling. Then, the refined Al6(Mn, Fe) particles inhibited the growth of recrystallization grains to refine them from 10.01 to 7.18 μm after cold rolling. Consequently, the tensile strength of the cold-rolled 5182 Al alloy increased from 414.65 to 454.34 MPa through cell-size strengthening, dislocation density strengthening, and particle strengthening. The tensile strength of the recrystallization annealed 5182 Al alloy was increased from 322.16 to 342.73 MPa through grain refinement strengthening, and this alloy was more stable after the recrystallization annealing temperature.

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“…Sharma et al [16] prepared the Al-11Si-20Cu brazing alloy containing La 2 O 3 by the electromagnetic induction casting process and found that the addition of La 2 O 3 significantly improved the filler brazeability, microhardness, joint tensile shear strength, and elongation of the composites. Elgallad et al [17] found that adding rare earth elements, La or Ce, to the Al-Si alloy increased the melting temperature of the alloy and caused partial modification of the eutectic Si particles. Liu et al [18] added different contents of CeO 2 and Y 2 O 3 (2 vol% and 3 vol%) to Ti/Al 2 O 3 composites prepared by vacuum hot pressing sintering to restrain the interface reaction.…”

Section: Introductionmentioning

confidence: 99%

Effect of CeO2 Content on Microstructure and Properties of SiCp/Al-Si Composites Prepared by Powder Metallurgy

et al. 2021

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The effect of CeO2 content on the microstructure and properties of SiCp/Al-Si composites prepared by powder metallurgy was studied, and the mechanism of CeO2 in composites was deeply analyzed. The results show that the addition of the appropriate amount of CeO2 can refine the Si particles and improve the tensile properties of the SiCp/Al-Si composites. As the CeO2 content increases from 0 to 0.4 vol%, the particle size of the Si phase shows a tendency to decrease first and then increase, while the tensile strength, yield strength, and elongation of the composites show a trend of first increasing and then decreasing. When the CeO2 content is 0.2 vol%, the refining effect of CeO2 and the tensile properties of composites are the best. The fracture mode of SiCp/Al-Si composites with a rare earth addition is a mixed fracture. There are three main mechanisms for CeO2 in SiCp/Al-Si composites. One is when CeO2 serves as the nucleation substrate of Si phase to refine Si particles. The second is when CeO2 reacts with the alloying elements in the aluminum matrix to form a new phase, CeCu2Si2, which can not only play a role of dispersion strengthening, but also improve the bonding strength between Al matrix and Si particles. The third is the pinning effect of CeO2 and CeCu2Si2 particles on grain boundaries or phase boundaries to refine aluminum grains.

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Effects of La and Ce Addition on the Modification of Al-Si Based Alloys

Cited by 34 publications

References 21 publications

Effect of Rare Earth Metals, Sr, and Ti Addition on the Microstructural Characterization of A413.1 Alloy

Effect of Rare Earth Metals, Sr, and Ti Addition on the Microstructural Characterization of A413.1 Alloy

Effects of Ce-Rich Mischmetal on Microstructure Evolution and Mechanical Properties of 5182 Aluminum Alloy

Effect of CeO2 Content on Microstructure and Properties of SiCp/Al-Si Composites Prepared by Powder Metallurgy

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