Project Details
Projekt
High Temperature Tensile and Tensile Fatigue Test Rig for Ceramic Matrix Composites
Subject Area
Materials Engineering
Term
Funded in 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 555004326
The requested high-temperature tensile and fatigue test rig for ceramic fiber composites consists of a servo-hydraulic test frame with suitable hydraulic fixtures for ceramic matrix composites (CMC) with usually flat rectangular or dogbone-shaped specimen geometry. Material testing can be carried out at temperatures of up to 1500 °C, whereby the specimen is heated by a short furnace with a high heating and cooling rate, which represent the measuring area of the specimen. The sample is clamped outside the furnace. It is possible to purge the heated zone with inert gas to prevent oxidation of the sample or, alternatively, to carry out the high-temperature test in ambient atmosphere. The testing rig allows uniaxial tensile testing and testing of the mechanical fatigue of CMCs at frequencies of up to 100 Hz and with a number of up to one million cycles. Both tension/tension and tension/compression tests are possible for dynamic testing. The control can be displacement or load-controlled. The maximum load is 100 kN. The strain measurement is carried out using non-contact optical measuring systems and digital image correlation (DIC). The test rig will be used to investigate the fatigue and failure behavior of CMCs at high temperatures and under inert or oxidative conditions. Of interest are mainly non-oxidic fiber composites, in particular carbon and silicon carbide fiber-reinforced silicon carbide (C/SiC and SiC/SiC). For example, the number of cycles until failure of the sample under dynamic load at a defined stress or the maximum possible stress for a certain number of cycles should be determined. The residual strength of the sample after dynamic loading, under high temperatures and/or under an oxidative atmosphere is also of interest. In addition, the failure mechanisms in the CMCs are to be investigated on the basis of the individual loading-unloading cycles, e.g. by determining the area enclosed by the hysteresis curves or the stiffness. In combination with microscopic methods, the debonding of fiber and matrix or the propagation of fatigue cracks under cyclic loading can be investigated. The influence of ceramic fiber coatings is also of interest here. The aim of these investigations is a detailed lifetime assessment of ceramic fiber composites under application-related environmental conditions, e.g. high temperatures and oxidative atmosphere.
DFG Programme
Major Research Instrumentation
Major Instrumentation
Hochtemperatur-Zug- und Ermüdungsprüfstand für keramische Faserverbundmaterialien
Instrumentation Group
2910 Dynamische Prüfmaschinen und -anlagen, Pulser
Applicant Institution
Universität Augsburg
