In-beam creep of SiCf/SiC minicomposites under uniaxial tensile loading

Abstract

A newly developed clamping system for ceramic specimen is described in the present report. By using this system, the uniaxial tensile loading was first successfully applied up to fracture (950 MPa) on a SiCf/SiC minicomposite. A minicomposite is a 1D model composite. It consists of a SiC-based fiber tow embedded in a SiC matrix, which has a diameter of about 0.5 mm. Afterwards, the irradiation creep properties of SiCf/SiC minicomposites were studied. In-situ creep was performed in an in-beam creep device under uniaxial tensile stresses from 40 to 382 MPa during homogeneous helium irradiation. Homogenous irradiation was carried out by helium implantation with energies varying from 0 to 45 MeV. The displacement dose rate was 1.2 × 10−6 dpa/s. The average temperature was controlled to 700 and 900 °C within ±15 °C. Irradiation creep compliance of minicomposite was measured to be 3.07 × 10−5 and 5.43 × 10−5 dpa−1 MPa−1 at 700 °C and 900 °C, respectively.