Abstract
Thermo-mechanical fatigue (TMF) tests of a unidirectionally reinforced SP700/SCS-6 composite were carried out, where the matrix alloy, SP700 is a new generation high strength titanium alloy. The damage evolution during the TMF was explored, through the investigations of the following articles, compared with that in the monolithic matrix alloy: (i) mechanical properties of both the SP700/SCS-6 composite and the matrix alloy at elevated temperatures; (ii) TMF and isothermal low cycle fatigue (LCF) failure lives of the composite and the matrix alloy, (iii) fiber push-out tests at elevated temperatures to represent the fiber/matrix inter facial strength; (iv) observation and the characterization of the interface by means of a transmission electron microscope (TEM) and an energy dispersive X-ray spectrometer (EDS); (v) crack initiation and the propagation during the thermal cycle test under no external loading; and (vi) changes of the interface during the TMF, LCF and thermal cycles. These systematic investigations showed that the lives and the failure mechanisms of the TMF should be clearly distinguished from those of the LCF, whereas there were a few similarities between them.
