Transverse cyclic behaviour of a unidirectional titanium based metal matrix composite in isothermal and thermomechanical conditions

摘要

Isothermal and non isothermal fatigue tests were performed between 200 and 600℃ in the transverse direction of a titanium matrix composite reinforced with unidirectional continuous SiC fibers (loading perpendicular to fiber axis). It was observed that interfacial decohesions and slidings are one of the main characteristics responsible for the non linear composite mechanical behaviour. A simple one dimensional 3 bars modelling in isothermal conditions demonstrated that accumulation of matrix viscoplasticity between fibers is also responsible for the non linear cyclic behaviour and that it is a key factor of the composite fatigue fracture.