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

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 (TM) 610 fibres by slurry infiltration and subsequent sintering at 1300 degrees 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. (C) 2016 Elsevier Ltd. All rights reserved.