SiC纤维增强钛基复合材料的横向力学性能

Transverse Mechanical Properties of Continuous SiC Fiber Reinforced Titanium Matrix Composites

采用十字形试样测试分析有C涂层和无C涂层两种SiC纤维增强钛基复合材料的横向力学性能,以横向载荷作用下应力-应变曲线上的非线性拐点计算界面的强度。结果表明,有C涂层的界面横向开裂强度为53MPa,低于无C涂层的界面开裂强度196MPa,并且前者在横向载荷作用下沿C涂层与纤维之间开裂,而后者沿反应生成物与基体间开裂;体积分数为30%的多根纤维钛基复合材料的非线性拐点应力低于单根纤维复合材料,这主要是由于残余应力的减少引起,界面强度并没有明显变化。

Transverse mechanical properties of TMCs reinforced by two types of SiC fibers with and without C coating were determined by use of cross-shaped specimens. The initial nonlinear stress of the stress-strain curve under the applied transverse tensile load was adopted to calculate the interface strength. The interface strength with C coating was 53 MPa which was lower than 196 MPa of the one without C coating. The debonding position of two interface were different, i.e. the former was between the fiber and C coating, but the latter was between the matrix and reaction products. The initial nonlinearity stress of TMCs reinforced by multiple fibers with 30% volume fraction was lower than that of single fiber reinforced TMCs, which was caused by the decrease of residual stress on the surface of fiber, and the interface strength was not influenced by the more additional fibers.