Formation of spherical primary silicon crystals during semi-solid processing of hypereutectic Al-15.5wt%Si alloy

Lee, J.I.; Lee, H.I.; Kim, M.I.

doi:10.1016/0956-716x(95)00043-u

Cited by 11 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This implies that the shear promotes the coarsening of silicon particles. Lee et al (1995) have also reported that significant fragmentation and changes of primary Si morphology occur for an Al-15.5%Si alloy during the isothermal stirring but little change was observed when a sample was continuously cooled at a shear rate of˙ = 200 s −1 and at a cooling rate of −0.03 • C s −1 . This shear rate however is able to fragment the dendritic morphology of the Mg 2 Si primary phase crystals with entrapped liquid as shown in Fig.…”

Section: Rheocasting Processmentioning

confidence: 90%

Effect of conventional and rheocasting processes on microstructural characteristics of hypereutectic Al–Si–Cu–Mg alloy with variable Mg content

Hekmat-Ardakan

Ajersch

2010

Journal of Materials Processing Technology

View full text Add to dashboard Cite

Section: Rheocasting Processmentioning

confidence: 90%

Effect of conventional and rheocasting processes on microstructural characteristics of hypereutectic Al–Si–Cu–Mg alloy with variable Mg content

Hekmat-Ardakan

Ajersch

2010

Journal of Materials Processing Technology

View full text Add to dashboard Cite

“…As evidenced by the figure, the liquid casting sample exhibits a solid inner structure, while the RDC sample assumes a typical imperfect octahedral shape with a hollow interior and cracks on the edges and corners. In a study by Lee [41], shearing forces were applied to the Al-15.5 wt% Si alloy for several hours at the isothermal semisolid state, leading to the fragmentation of the primary Si along {100} planes and cleavage along {110} planes. While Lee attributed the origin of the cracks to the mutual collision between the primary Si, no discussion was offered on crystal nucleation and growth.…”

Section: Effect Of Rdc On Crystal Growth Of the Primary Simentioning

confidence: 99%

Improving Mechanical Property of Hyper-Eutectic Al-Si Alloys via Regulating the Microstructure by Rheo-Die-Casting

Huo

Chen³

et al. 2023

Metals

View full text Add to dashboard Cite

The microstructure plays a key role in the mechanical properties of hyper-eutectic Al-Si alloys. In this study, we investigate the microstructural evolution of rheo-die-casting (RDC) on the Al-15Si-4Cu-0.5Mg alloy using a mechanical rotational barrel system. Our findings demonstrate that higher rotational speed and pouring temperature reduce the size and roundness of primary Si particles in the semisolid slurry. Additionally, during RDC, the dendritic aluminum matrix and skeletal iron-containing inter metallics are sheared off, leading to a more uniform and dispersed Al2Cu phase. Ultimately, our rheo-diecasting results indicate the formation of a near globular aluminum matrix, fine primary Si particles, and a homogeneous Al2Cu phase, thus highlighting the efficacy of this processing method for improving the microstructure and properties of the Al-15Si-4Cu-0.5Mg alloy. We suggest that these results hold promise for enhancing the quality of aluminum-based alloys in various industrial applications.

show abstract

“…Additionally, there is evidence in the literature of agglomeration of primary silicon particles in Al-Si alloys, [36,37] and that silicon boundaries, generally, have a tendency to adopt special, low-energy, geometries. [38,39] …”

Section: E Contribution To Growth Rate From Agglomerationmentioning

confidence: 99%

Inhibited coarsening of a spray-formed and extruded hypereutectic aluminum-silicon alloy in the semisolid state

Hogg

Atkinson

2005

Metall Mater Trans A

View full text Add to dashboard Cite

The microstructural evolution of a spray-formed and extruded hypereutectic aluminum-30 pct silicon-5 pct copper-2 pct magnesium alloy heated into the semisolid state has been investigated. Liquid is formed initially by a quaternary eutectic reaction and then by a ternary melt reaction. These reactions occur relatively quickly. However, the binary Al-Si eutectic melt reaction takes a significant time-around several hours depending on the temperature. The coarsening rate constants (K) for the growth of the silicon particles are approximately three to four orders of magnitude lower than those for the majority of metal spray-formed alloys. This may be associated with difficulties in addition or removal of atoms from the low index silicon facets. Where growth does occur, agglomeration of silicon particles may play a large role, especially at higher liquid contents. Electron backscatter diffraction (EBSD) gives evidence of agglomeration, and furthermore shows that high-angle silicon-silicon boundaries are not wetted with liquid.

show abstract

Formation of spherical primary silicon crystals during semi-solid processing of hypereutectic Al-15.5wt%Si alloy

Cited by 11 publications

References 7 publications

Effect of conventional and rheocasting processes on microstructural characteristics of hypereutectic Al–Si–Cu–Mg alloy with variable Mg content

Effect of conventional and rheocasting processes on microstructural characteristics of hypereutectic Al–Si–Cu–Mg alloy with variable Mg content

Improving Mechanical Property of Hyper-Eutectic Al-Si Alloys via Regulating the Microstructure by Rheo-Die-Casting

Inhibited coarsening of a spray-formed and extruded hypereutectic aluminum-silicon alloy in the semisolid state

Contact Info

Product

Resources

About