Bending fatigue behavior in an advanced SiC/SiC ceramic matrix composite component at elevated temperature in air

• DOI: 10.1016/j.jcomc.2021.100127
• Publication Date: 2021-03-07T20:58:10Z
• Authors: Amit Patel; Eiichi Sato; Takeshi Takagi; Naohiro Shichijo
• Keywords: Ceramic matrix composite; Brittleness

The present study aims to understand the high-temperature bending fatigue behavior at stress-concentrated Y-shape junction of a component made Tyranno SA3 fiber/BN interphase/SiC matrix composite. SiC/SiC CMC was processed via hybrid technique by combining Chemical Vapor Infiltration (CVI) and Polymer Impregnation Pyrolysis (PIP) processes. Two different types tests, namely, point-load-bending-static-test point-load-bending-fatigue-test, were performed 1100 °C. point-load-bending-static test revealed quasi-ductile or shear failure owing lower elastic modulus PIP-SiC matrix. first matrix-cracking occurred when high-stress region reached approximately 180 MPa, which facilitated pores cracks that remained after PIP process around intricate sample. point-load-bending-fatigue tests under maximum stresses ranging from 290 MPa. When stress than 60% static strength, multiple pronounced such did not fail withstand 1000 cycles. At higher 250 delamination due generation fiber tows interface degradation BN interphase ultimately led fracture low cycles less 100. Moreover, morphology 290-MPa-fatigue sample showed brittle failure, matrix-crack-assisted oxygen embrittlement. In addition, brief comparison between conventional tension-compression discussed.