Novel Rare Earth-Bearing Ultra-High-Temperature Ceramics Tested in a Solar Furnace Above 2,200 A degrees C in Air

作者：Rebillat Francis^*; Andreani Anne Sophie; Poulon Quintin Angeline

来源：Oxidation of Metals, 2013, 80(3-4): 257-266.

DOI：10.1007/s11085-013-9383-1

• Solar furnace
• Dysprosium
• Oxidation mechanism

A novel method for testing ultra-high-temperature ceramics (UHTC) at very high temperature (above to 2,200 A degrees C) in air with an exposure time of several minutes is used. The well-known ZrB2 + SiC material shows a limited temperature of use in an oxidizing environment due to the low stability above 2,000 A degrees C of any silica that is formed. A few new systems without silicon are proposed, starting with the Hf or Zr, C, B and rare earth elements. The choice of rare earths is motivated by the formation of oxides with melting points higher than 2,000 A degrees C. The complex oxide scales formed during oxidation are accurately described, in terms of presence of porosity and gradients of composition. Similarities with the mechanism of oxidation described for ZrB2 + SiC materials are shown. A significantly higher thermal stability of rare-earth oxide containing ceramics compared to silica is highlighted. As a consequence, the protective capacity of the oxide scale is improved.

• 出版日期2013-10