Creep Behavior of an Oxide/Oxide Composite with Monazite Coating at Elevated Temperatures

This study focuses on experimental investigation of stress-rupture behavior (creep response) of an oxide/oxide composite in a cross-ply (0/90) lay-up at elevated temperature. The test material, Nextel 610/monazite/alumina composite, employs monazite, an oxidation-resistant interfacial coating designed to improve performance at elevated temperatures. The experimental program included monotonic tensile tests to failure and creep-rupture tests at elevated temperatures. Tensile tests served to establish an ultimate tensile strength (UTS) for the material. The ensuing creep-rupture tests involved stress levels at varying percentages of the UTS. Stress-rupture curves at 900 and 1100oC were established. A family of creep curves for various constant stress levels at 900 and 1100oC was produced. Composite microstructure, as well as damage and failure mechanisms were also investigated.