Insight into hexacelsian-to-celsian transformation in hot-pressed BN/BAS composites

This study aims to elucidate the phase transformation of hexacelsian-to-celsian in 10 wt.% h -BN reinforced BaAl 2 Si 2 O 8 (BN/BAS) composites fabricated by hot-pressed at 1300 °C for different holding time. Results showed that the relationship between the transformation fraction of celsian and the holding time displays a typical “S” curve according to Johnson-Mehl-Avrami equation. During the hexacelsian-to-celsian transformation, a transitional phase of paracelsian was observed. Celsian tended to nucleate and grow up along the (110) P habit plane of paracelsian by a non-diffusive transition behavior. During transformation, celsian and paracelsian present an oriented intergrowth with orientation relations of (110) P //(020) M , [001] P //[101] M and [ 1 1 ¯ 0 ] P // [ 10 1 ¯ ] M .