Fatigue behavior of Nextel™ 312/Blackglas™ ceramic matrix composite with tensile and zero mean load

Abstract

This study characterized a woven fabric reinforced ceramic matrix composite, Nextel™ 312/Blackglas™, under monotonic and fatigue loading conditions at room and elevated (760°C) temperatures in order: (1) to investigate monotonic tensile and compressive loading behavior at room and elevated temperatures, (2) to establish the fatigue life diagrams (S - N curves) with tensile and zero mean load under low frequency (0.1 Hz) cycling condition at room and elevated temperatures, and (3) to investigate damage mechanisms and failure modes under monotonic and fatigue loading conditions. Fatigue lives under tension-compression cycling were much longer than those under tension-tension cycling at a given stress range for both room and elevated temperatures. However, fatigue lives under tension-compression cycling were much shorter than those under tension-tension cycling for a given maximum stress level at room temperature, but lives were about equal under these two loading conditions for a given maximum stress level at elevated temperatures. Further, fatigue lives were much shorter at elevated temperature than their counterparts at room temperature for a given stress range or for a given maximum stress level under the both tension-tension and tension-compression cycling conditions.