Electron microscope study of Al-Fe-Si intermetallics in 6201 aluminum alloy

Mulazimoglu, M. H.; Załuska, A.; Gruzleski, J. E.; Paray, F.

doi:10.1007/bf02649760

Cited by 146 publications

(77 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Under the assumptions in Figure 14(b), the formation of Al 13 Fe 4 , a-AlFeSi, b-AlFeSi, a-AlMnSi, Mg 2 Si, and Si in sequence from the liquid during solidification were predicted, and in general the following possible variant and invariant solidification reactions have been suggested for 6xxx series Al alloys: [7,[30][31][32][33] …”

Section: Solidification Sequence and Fe-imc Phase Selectionmentioning

confidence: 99%

“…[3,4] Previous studies show that a c -AlFeSi and b-AlFeSi are the two dominant Fe-IMCs in 6063 Al alloys. [5][6][7][8] 3D analysis of these Fe-IMCs after extraction from the primary a-Al using an Al dissolution approach revealed that a c -Al(FeMn)Si (from now referred to as a c -AlFeSi) had a dendritic-like morphology while b-AlFeSi had a plate-like morphology. [9] Among these IMCs, it has been noted that b-AlFeSi in particular, because of its more planar geometry, reduced the ductility of an Al alloy 6063.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evolution of Fe Bearing Intermetallics During DC Casting and Homogenization of an Al-Mg-Si Al Alloy

Kumar

Grant

O’Reilly

2016

Metall Mater Trans A

View full text Add to dashboard Cite

The evolution of iron (Fe) bearing intermetallics (Fe-IMCs) during direct chill casting and homogenization of a grain-refined 6063 aluminum-magnesium-silicon (Al-Mg-Si) alloy has been studied. The as-cast and homogenized microstructure contained Fe-IMCs at the grain boundaries and within Al grains. The primary a-Al grain size, a-Al dendritic arm spacing, IMC particle size, and IMC three-dimensional (3D) inter-connectivity increased from the edge to the center of the as-cast billet; both a c -AlFeSi and b-AlFeSi Fe-IMCs were identified, and overall a c -AlFeSi was predominant. For the first time in industrial billets, the different Fe-rich IMCs have been characterized into types based on their 3D chemistry and morphology. Additionally, the role of b-AlFeSi in nucleating Mg 2 Si particles has been identified. After homogenization, a c -AlFeSi predominated across the entire billet cross section, with marked changes in the 3D morphology and strong reductions in inter-connectivity, both supporting a recovery in alloy ductility.

show abstract

Section: Solidification Sequence and Fe-imc Phase Selectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evolution of Fe Bearing Intermetallics During DC Casting and Homogenization of an Al-Mg-Si Al Alloy

Kumar

Grant

O’Reilly

2016

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…The Sr adsorbs to the latter and prevents 93 the diffusion of silicon (which builds up at the a-AlFeSi/Al-matrix interface) into the a-AlgFe2Si phase, resulting in an absence of P-AlsFeSi needles in the microstructure. 130 Apparently, during solidification, the Sr addition leads to local segregation of iron in certain areas, such that the Fe/Si ratio is > 1, which favors precipitation of iron intermetallics in the form of the compacted a-AlgFe2Si phase. 131 Villeneuve and Samuel 62 reported that the addition of a sufficiently high concentration of Sr (~350 ppm) to Al-13 wt% Si-Fe alloys breaks down the P-needles into small, thin fragments through (i) splitting of the needles into two halves, and…”

Section: Effect Of Sr Modificationmentioning

confidence: 99%

Paramètres métallurgiques contrôlant l évolution microstructurale dans les alliages de fonderie Al-Si-Mg et Al-Si-Cu

Liu¹

2004

View full text Add to dashboard Cite

With their characteristics of low specific gravity, low melting point, excellent castability and good corrosion resistance, aluminum-silicon (Al-Si) alloys are extensively employed in automotive applications. Castings produced from these alloys range from transmission cases and intake manifolds to more critical components such as engine blocks, cylinder heads and wheels.Two of the most popular commercial alloys used in such applications are the A356 and 319 type alloys, belonging to the Al-Si-Mg and Al-Si-Cu alloy systems. The casting quality and properties are determined by the quality of their microstructure, controlled by various parameters such as the dendrite arm spacing (DAS -as determined by the solidification rate), the degree of eutectic Si modification and grain refinement, and the amount of microporosity, intermetallics and inclusions observed in the microstructure. Among these, solidification rate is the most important, as it directly or indirectly affects almost all the other microstmctural parameters.Modification of the eutectic silicon morphology from its acicular, flake-like form to a fibrous form is usually carried out through the addition of strontium (Sr) to improve the alloy ductility. Intermetallics commonly present in these alloys are the P-AlsFeSi and a-Al 5 (Fe,Mn) 3 Si2 iron intermetallics, sludge, Mg2Si and, in the case of 319 alloys, the copper intermetallic, CuAl 2 . Due to its brittle, platelet-like nature, the P-AlsFeSi iron intermetallic can be quite deleterious to the alloy properties, as can the presence of porosity, particularly in terms of surface quality and soundness.The aim of the present work has been to investigate the metallurgical parameters controlling the microstmctural evolution of Al-Si-Mg and Al-Si-Cu alloys, through a study of the microstmctural characteristics of directionally solidified A356 and 319 type alloys as a function of iron content, Sr addition (~250 ppm), and cooling rate. The iron levels selected varied from 0.12 to 0.8 wt pet, and cover the range of Fe levels found in commercial casting alloys. The use of an end-chill mold provided different cooling rates along the height of the same casting, with DAS values that varied from ~23 to 85 |^m, corresponding to levels of 5, 10, 30, 50 and 100 mm above the chill end.The effects of these variables on the precipitation of the P-Al 5 FeSi phase, the characteristics of the a-Al dendrite stmcture, eutectic silicon modification, and porosity formation were examined in detail. Various techniques were used for microstmctural characterization and phase identification, including optical and scanning electron microscopy, electron probe microanalysis coupled with energy dispersive X-ray (EDX) and wavelength dispersive spectroscopy (WDS) facilities, and thermal analysis. An image analyzer was used in conjunction with the optical microscope for quantification purposes.

show abstract

“…The formation of the -phase can be promoted by a proper heat treatment of the foam or by adding certain transition elements to the alloy prior to the solidification. 5) Nevertheless, the exact influence of the -phase (with or without a heat treatment) on the ductility of the cell wall is unknown. When -AlFeSi plates are removed from the microstructure the strength and ductility of the cell walls depends on the size distribution, strength distribution and volume fraction of the SiC particles.…”

Section: Discussionmentioning

confidence: 99%

Fracture Behavior of Metal Foam Made of Recycled MMC by the Melt Route

et al. 2006

View full text Add to dashboard Cite

Metal foam was made from recycled MMC precursor by the melt route. The original starting material was an Al-9Si alloy containing 20 vol% of SiC particles (10 mm), which are used to stabilize the foam during the foaming process. The starting material has been used to make foam parts from which the residue was recycled and refoamed. During the (re)foaming process Fe is present in the melt. During solidification of the foam, -AlSiFe plates are formed with the surplus of Si and Al present in the alloy. These plates run through the entire thickness of the cell wall (40-50 mm) and their length ranges between 50 and 200 mm. During in-situ tensile tests fracture initiates in the -AlFeSi plates and propagates through other -AlFeSi plates leading to brittle fracture of the cell walls.

show abstract

Electron microscope study of Al-Fe-Si intermetallics in 6201 aluminum alloy

Cited by 146 publications

References 20 publications

Evolution of Fe Bearing Intermetallics During DC Casting and Homogenization of an Al-Mg-Si Al Alloy

Evolution of Fe Bearing Intermetallics During DC Casting and Homogenization of an Al-Mg-Si Al Alloy

Paramètres métallurgiques contrôlant l évolution microstructurale dans les alliages de fonderie Al-Si-Mg et Al-Si-Cu

Fracture Behavior of Metal Foam Made of Recycled MMC by the Melt Route

Contact Info

Product

Resources

About