Investigation of the microstructure of the Al–Si eutectic in binary aluminium–7 wt% silicon alloys by electron backscatter diffraction (EBSD)

The influence of strontium on porosity formation in Al-Si alloys

“…It is well established that the eutectic aluminum shares a crystallographic orientation relationship with the primary aluminum in unmodified alloys, but not in Sr-modified foundry alloys. [20][21][22][23][24][25][26] The relative crystallographic orientations of the eutectic aluminum and the primary aluminum is evidence that the eutectic nucleates and grows from the dendrites in unmodified alloys and independently of the dendrites in Sr-modified alloys.…”

“…Investigations of the eutectic nucleation and growth mode using electron backscatter diffraction show that in unmodified alloys there is a direct crystallographic orientation relationship between the eutectic aluminum and the adjacent primary aluminum dendrites. [20][21][22][23][24][25][26] The crystallographic orientation relationship suggests that the eutectic grains nucleate on the primary dendrites. This orientation relationship is not present in alloys of commercial purity modified by strontium additions typical of foundry practice, suggesting that the eutectic grains nucleate independently of the primary aluminum dendrites in the interdendritic liquid.…”

“…This orientation relationship is not present in alloys of commercial purity modified by strontium additions typical of foundry practice, suggesting that the eutectic grains nucleate independently of the primary aluminum dendrites in the interdendritic liquid. It has been observed that eutectic aluminum in commercial purity Al-Si alloys with very high levels of strontium (approximately 500 ppm) [21] and in high-purity Al-Si alloys with 150 ppm Sr [26] has a crystallographic orientation relationship with the primary aluminum dendrites. Therefore, in these latter cases, the eutectic nucleation mode is the same as in unmodified alloys.…”

Microstructural characterization using orientation imaging microscopy of cellular Si/SiC ceramics synthesized by replication of Indian dicotyledonous plants

“…Such a model is far from complete, but appears reasonable as an approximation in explaining the presence of graphite inside the residual Si. The large Si grains had dominant presence of 3 twin boundaries -such boundaries are often reported 48 during solidification of liquid Si.…”

Some Applications of Electron Back Scattering Diffraction (EBSD) in Materials Research

“…more than 50% [Heiberg & Arnberg, 2001] and influences its mechanical properties. The coarse primary α-Al dendrite could be refined and equiaxed by adding proper quantities of Ti and B into the alloy [Easton & St John, 2001;Shabestari & Malekan, 2010], while Sr is a good modificator, which improves the mechanical properties of Al-Si alloy by changing the morphology of the eutectic Si [Chen & Zhang, 2010;Martínez et al, 2005].…”