Cerium-silicon system

The Ce-Si phase diagram was constructed by means of differential thermal, X-ray and metallography examination of 15 as-cast key alloys. Ce5Si3, Ce3Si2, Ce5Si4, CeSi were confirmed. Two cerium disilicides were found, CeSi2-a1 (alpha-GdSi2 structure type) and CeSi2-a2 (alpha-ThSi2 structure type). The two-phase region CeSi2-a1 +CeSi2-a2 is very narrow. CeSi and CeS2-a1 melt congruently at 1630 and 1725 degreesC, respectively. The intermetallics Ce5Si3, Ce3Si2 Ce5Si4, CeSi2-a1 form in peritectic reactions at 1260, 1335, 1500 and similar to1575 degreesC, respectively. Three eurectics occur at 635, 1532+/-12 and 1198+/-2 degreesC and the compositions 10.5, 55 and 82 at% Si, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.