The purpose of this work was to select materials for applications in oxidizing atmospheres at temperatures of a minimum of 1500 degrees C. Several requirements had to be fulfilled e.g. long-term oxidation resistance, low vapour pressure, high creep resistance and low gas permeability,. Another important point was to avoid reactions and sintering in material combinations,vith silica forming materials. The investigation was based on a detailed literature screening, followed by compatibility tests at 1600 degrees C in air with potential materials (Al2O3, ZrO2, CeO2, La2O3, Y2O3, HfO2, MgO . Al2O3) and Mosi(2) as an example of a silica-forming material. The result of these experiments was, that only Y2O3 and HfO2 did not show severe reactions in contact with MoSi2. Since most of the materials available did not fulfill all the requirements, some new materials were investigated. CIPed MoSi2 with different additives (SiC, ZrB2) and recrystallized SiC (RSiC) with a polymer (polysiloxane) derived MoSi2-filled coating. The oxidation behaviour of these materials was evaluated by continuous thermogravimetric measurements at 1500 degrees C over a period of 100 h in air and by detailed postexperimental investigations. (C) 1999 Elsevier Science Limited. All rights reserved.
