Gant, A J; Morrell, R (1999) CPD3 T3: Thermal cycling and mechanical properties of a unidirectional titanium matrix composite and a cross-ply ceramic matrix composite. NPL Report. CMMT(A)188

Text CMMT188.pdf Download (3MB)

Abstract

Recently there has been some interest in the use of ceramic matrix composites and titanium matrix composites in high temperature aerospace applications; specifically jet engine components such as bladed rings in engine compressors. Such materials have been characterised extensively as far as interfaces and a range of mechanical properties are concerned either at ambient or elevated temperatures, but relatively little work has been done on evaluating structure/property relationships in such materials subjected to thermal cycling to elevated temperatures, representative of in-service conditions. The materials used in the present study and subjected to thermal cycling were a unidirectional titanium/silicon carbide MMC and a cross ply barium osumilite glass ceramic CMC. The effects of thermal cycling on the interfaces in these materials were studied at room temperature, with and without subsequent mechanical testing. Scanning electron microscopy was primarily used to characterise the interfaces, together with monotonic and fatigue data in uniaxial tension; the latter being used, where possible, to relate interface response to bulk mechanical properties. In both the MMC and the CMC, property changes were observed after cycling to the lowest temperatures in the test regime; 450°C and 500°C respectively. Degradation of the CMC was progressive across the temperature regime studied, whereas in the TMC no consistent trends in bulk mechanical properties were seen due to the effect of microscopic interfacial changes being effectively masked by changes in matrix condition, caused by thermal cycling.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	CMMT(A)188
Subjects:	Advanced Materials Advanced Materials > Mechanical Measurement
Last Modified:	02 Feb 2018 13:18
URI:	http://eprintspublications.npl.co.uk/id/eprint/1145

Actions (login required)

View Item