In this paper, TaC-based/graphite fibrous monolithic ceramics made of fibers with three core/shell volume ratios (75/25, 70/30, and 65/35) and two orientations of 0° and 0°/90° were prepared. Then, the effects of fiber core/shell volume ratio and fiber orientation on the microstructure and room temperature mechanical properties were investigated. Hot pressing at 1800 °C for 60 min under 40 MPa resulted in the maximum relative density for [0°] specimens with the minimum shell thickness. The work of fracture and fracture toughness of FM specimens with 0°/90° fibers orientations were calculated lower than samples with 0° fibers orientations at the same core/shell volume ratio. SEM observations of fracture surfaces and side surfaces of specimens approved these data. So that delamination and fiber pullout occurred in a minimized extent for the specimens with the bi-directional architecture of [0°/90°] compared to the unidirectional architecture of [0°]. The results disclosed that the fracture toughness of 6.6 ± 0.4 MPa m^1/2 and work of fracture of 2145 ± 56 J/m², as the highest values, were obtained for C70/S30-[0°] specimens.

本文制备了TaC基/石墨纤维整体陶瓷，该陶瓷由具有三种核/壳体积比（75 / 25、70 / 30和65/35）且两个方向分别为0°和0°/ 90°的纤维制成。然后，研究了纤维核/壳体积比和纤维取向对显微组织和室温机械性能的影响。在40 MPa下于1800°C进行60分钟的热压可得到[0°]标本的最大相对密度，而其外壳厚度最小。计算得出，在相同的核/壳体积比下，纤维取向为0°/ 90°的FM样品的断裂功和断裂韧性低于纤维取向为0°的FM样品。样品的断裂表面和侧面的SEM观察证实了这些数据。因此，与[0°]的双向结构相比，[0°/ 90°]的双向结构的试样在最小程度上发生了分层和纤维拔出。结果表明，断裂韧性为6.6±0.4 MPa m对于C70 / S30- [0°]标本，获得了^1/2的最高断裂功和2145±56 J / m ²的断裂功。