Tensile strength distribution of all-oxide ceramic matrix mini-composites with porous alumina matrix phase

Abstract

The mechanical behaviour of all-oxide ceramic matrix mini-composites with porous alumina matrix phase was investigated by performing uniaxial tensile tests on specimens with different gauge lengths. The specimens were fabricated from Nextel™ 610 fibres by slurry infiltration and subsequent sintering at 1300 °C for 1 h. The stress–strain curves of the tested mini-composites revealed that the porous alumina matrix phase accumulates damage with increasing tensile load, but continues to contribute to the mini-composites’ tensile stiffness until ultimate failure occurs. A dependence of the tested mini-composites’ axial tensile strength on gauge length was not observed. The mean stress in the fibres at mini-composite failure was found to decrease with increasing matrix volume fraction, indicating that the cause of ultimate failure of the mini-composites can be attributed to the propagation of matrix cracks.