Fabrication of highly dense three‐layer SiC cladding tube by chemical vapor infiltration method

Abstract

AbstractThree‐layer silicon carbide (SiC) cladding architectures are considered to be promising materials for current light‐water nuclear reactors. Herein, a novel processing approach was proposed to fabricate dense three‐layer SiC tubes by introducing SiC nanowires (NWs) on the graphite rod, which resulted in change in the valley‐peak structure of SiCf tubular preform. A dense three‐layer‐NWs SiC cladding tube, consisting of a chemical vapor infiltration (CVI)‐SiC inner layer, a CVI‐SiCf/SiC composite layer, and a CVI‐SiC outer layer, was obtained through CVI process. Microstructure and hoop strength of the as‐obtained three‐layer‐NWs SiC cladding tube were systematically investigated. By avoiding delamination of the layers and reducing the pores, the three‐layer‐NWs SiC cladding tube exhibited an average hoop strength of 316.6 MPa with a Weibull modulus of 11.55.