采用在厚度方向引入Z-pin的方法,增强C/SiC陶瓷基复合材料层压板的层间性能。碳纤维平纹编织物和碳纤维Z-pin制备的预成型体,通过化学气相渗透工艺制成Z—pin增强平纹编织陶瓷基复合材料层压板。采用单向拉伸和压缩试验研究层压板的拉伸和压缩力学性能,通过扫描电子显微镜观察断口形貌,对拉伸试样和压缩试样断口进行了分析。试验结果表明:Z-pin增强平纹编织陶瓷基复合材料拉伸和压缩都具有非线性力学特性。断口扫描结果发现,拉伸破坏表现出基体开裂、面内纤维束断裂拔出的破坏机理,而压缩破坏机制则表现为纬向纤维束内的基体裂纹和层间裂纹的产生和扩展,最后,Z-pin和经向纤维束剪切断裂。
Interlaminar property of C/SiC ceramic matrix composite (CMC) laminates was reinforced through the thickness by insertion of Z-pins. A preform consisting of plain woven carbon fabric and carbon fiber Z-pins was prepared and then fabricated Z-pin reinforced plain-woven ceramic matrix composite laminate by chemical vapor infil- tration (CVI). Uniaxial tensile and compression tests were used on specimens of Z-pin reinforced plain-woven ce- ramic matrix composite to investigate its mechanical properties. The fracture patterns were observed through scan- ning electronic microscope (SEM) and were analyzed. The results show that the tensile and compression of Z-pin reinforced plain-woven ceramic matrix composite laminates have nonlinear characteristics. SEM observation shows that matrix cracking, in-plane fibre fracture and pull-out are tensile failure mechanisms, and that the initiation and propagation of matrix crack in transverse yam and delamination crack, and final shear fracture of longitudinal yam and Z-pins are compression failure mechanisms.