Tensile strength degradation of ceramic fibres due to cyclic loading


KAYA F.

JOURNAL OF MATERIALS SCIENCE, cilt.42, ss.1096-1107, 2007 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 42 Konu: 4
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1007/s10853-006-1369-9
  • Dergi Adı: JOURNAL OF MATERIALS SCIENCE
  • Sayfa Sayısı: ss.1096-1107

Özet

Interfacial strength of Ti beta 21S/SCS 6 composite was increased via ageing. Composite specimens with a(o)/W ratios of 0.24 and 0.07 were prefatigued in three point bending at ambient and at 500 degrees C both in the air and vacuum. Bridging fibres were extracted from the pre-fatigued specimens and tested in tensile loading to monitor the strength degradation due repeated opening and closing of the fatigue crack. A tri-modal Weibull distribution was employed to express strength distribution of the SCS 6 fibres. Results have shown that cyclic loading of the composites lower the mean tensile strength of the fibres by 20%, compared to the unfatigued composite. A marked effect of initial unbridged defect size was observed, when the tensile strength data were divided into two sub-population using the fatigue crack length values. Compared to unfatigued composite, tensile strength reductions of 41 and 22% were measured from the prefatigued composites with a(o)/W of 0.24 and 0.07, respectively.