Eutectic grain size and strontium concentration in hypoeutectic aluminium–silicon alloys

A solidification model for unmodified, Na-modified and Sr-modified Al-Si alloys

“…The results correspond with experimentally obtained data and observations reported in the literature [2][3][4][5]. It has been shown that the number of available sites for nucleation is reduced when Sr is added to Al-Si alloys [2].…”

“…As described by Dahle et al [2][3][4]11] it is assumed that the eutectic nucleates in the melt between the dendrites and that they grow as spherical grains in the interdendritic liquid. In Stage 3 the number of eutectic cells per m 3 formed in each time step is calculated.…”

“…The eutectic grain size of Sr-modified alloys is larger than that of Na-modified alloys. Due to recalescence the eutectic grows at varying velocity, and the shape and scale of the eutectic silicon varies from the centre of the eutectic grain to the intercellular region as described by McDonald et al [3,4]. Other than modification, it is well known that the local cooling rate in the melt influences nucleation and growth of the eutectic.…”

Impact of P and Sr on solidification sequence and morphology of hypoeutectic Al–Si alloys: Combined thermodynamic computation and phase-field simulation

“…Most of the recent studies, in contrast, rather focus on the impact of Sr on nucleation of eutectic (Si). McDonald et al found that Sr addition significantly reduces the nucleation frequency [15]. Dahle et al [16] suggested that this might be due to formation of the Al 2 Si 2 Sr phase, which competitively nucleates onto AlP thus reducing the potency of these particles for (Si) nucleation.…”

Permeability of dual structured hypoeutectic aluminum alloys

“…Al-20 wt.% Cu, and casting procedure. Although low grain densities were not achieved for the Al-Cu system, it has been reported that Sr addition to Al-Si alloys inhibits the nucleation of eutectic grains and dramatically decreases the eutectic grain density [34]. The modeling technique was used to produce numerically calculated permeabilities for eutectic grain densities varying from 6 to 90 mm À3 .…”