Mechanical and thermal properties of a Hf2[Al(Si)]4C5 ceramic prepared by in situ reaction/hot-pressing

Predominantly single-phase Hf(2)[Al(Si)(4)]C(5) ceramic hits been fabricated by an Ill Situ reaction/hot-pressing method using Al. Si and graphite its starting materials Hf(2)[Al(Si)](4)C(5) Shows comparable mechanical properties to Zr(2)[Al(Si)](4)C(5), and lower hardness and stiffness but higher strength and toughness than HfC The stiffness decreases slowly with temperature and at 1600 degrees C it remains 83% of that at ambient temperature Compared to Zr(2)[Al(Si)](4)C(5) and HfC, however, Hf(2)[Al(Si)(4)C(5) exhibits it relatively higher coefficient of thermal expansion,. all intermediate specific heat capacity and it lower thermal conductivity (C) 2009 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved