Papers by Keyword: La

Abstract: Al₂O₃·SiO_2f/A356 composites contained La were fabricated by squeeze casting, and effect of La on the solute segregation and microstructure were researched. The results indicate that the microstructure in the composite can be refined by La, which enriches near the interface to be favorable to improve the wettability between the fiber and Al alloy. The phases RE-richening do not formed at the interface. There is no special influence of La on the Mg segregation in the matrix alloy. The distribution of Mg and La in the composite are near the interface.

Abstract: Specific investigations concerning La-contributions in graphite nucleation process in Ca,Al,La-FeSi inoculated grey cast irons were performed by using a scanning electron microscopy (SEM, EDS). It was re-confirmed that complex (Mn,X)S compounds act as major nucleation sites for graphite flakes. La was mainly concentrated in the first formed oxide-based micro-inclusions (similarly to Al), but also at an important level in the shell of (Mn,X)S compounds (accompanying Ca). It is assumed that La forms micro-inclusions later than Al, as La-reached phase surrounded Al-reached phase. Complex Al-La small micro-inclusions, as possible better nucleation sites for (Mn,X)S compounds and La-Ca presence in the shell/body of these sulphides, possible better nucleation sites for flake graphite, appear to be the peculiar effects of ferrosilicon based inoculants, which include these active elements, promoting type-A graphite, inclusively in low S-grey iron.