先驱体浸渍-裂解SiC界面改性涂层对气相渗硅3D-Cf/SiC复合材料力学性能的影响  

Effects of precursor infiltration-pyrolysis SiC interphase modified coating on mechanical properties of 3D-C_f/SiC composites prepared by gaseous silicon infiltration process

作　　者：刘荣军[1] 曹英斌[1] 龙宪海[1] 杨会永[1] 曹宇[1] 

机构地区：[1]国防科学技术大学航天科学与工程学院,新型陶瓷纤维及其复合材料重点实验室,长沙410073

出　　处：《复合材料学报》2016年第6期1266-1273,共8页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51102282);国防科学技术大学科研计划(JC14-01-01)

摘　　要：界面改性涂层对调节复合材料的力学性能起到重要作用。特别是在气相渗硅(GSI)制备C_f/SiC复合材料时,合适的界面改性涂层一方面保护C纤维不受Si反应侵蚀,另一方面调节C纤维和SiC基体的界面结合状况。通过在3D-C纤维预制件中制备先驱体浸渍-裂解(PIP)SiC涂层来进行界面改性,研究了PIP-SiC涂层对GSI C_f/SiC复合材料力学性能的影响。结果表明:无涂层改性的GSI C_f/SiC复合材料力学性能较差,呈现脆性断裂特征,其弯曲强度、弯曲模量和断裂韧性分别为87.6 MPa、56.9GPa和2.1 MPa·m^(1/2)。具有PIP-SiC界面改性涂层的C_f/SiC复合材料力学性能得到改善,PIP-SiC涂层改性后,GSI C_f/SiC复合材料的弯曲强度、弯曲模量和断裂韧性随着PIP-SiC周期数的增加而降低,PIP-SiC为1个周期制备的GSI C_f/SiC复合材料的力学性能最高,其弯曲强度、弯曲模量、断裂韧性分别为185.2 MPa、91.1GPa和5.5 MPa·m^(1/2)。PIP-SiC界面改性涂层的作用机制主要体现在载荷传递和"阻挡"Si的侵蚀2个方面。The interphase modified coating plays a vital role in adj usting the mechanical properties of composites,in particular for those Cf/SiC composites prepared from the gaseous silicon infiltration （GSI）process.The ideal inter-phase modified coating should not only prevent the etching of C fiber by Si vapor,but also render a good interface bonding between C fiber and SiC matrix.With SiC coatings from the precursor infiltration-pyrolysis （PIP）route as the interphase modified coating in 3D-C fiber preform,we discuss the effects of PIP-SiC coating on mechanical prop-erties of Cf/SiC composites made from GSI.The results show that,without coating modification,the GSI Cf/SiC composites have poor mechanical properties and show brittle fracture characteristic,with the flexure strength,flex-ure modulus and fracture toughness 87.6 MPa,56.9 GPa and 2.1 MPa·m^1/2 ,respectively.Those composites with PIP-SiC interphase modified coating exhibit better mechanical properties,with PIP-SiC coating modification,with the increase of the PIP-SiC cycles,flexure strength,flexure modulus and fracture toughness of GSI Cf/SiC compos-ites decrease,in particular those with the PIP-SiC coatings after one cycle,with the flexure strength,flexure modu-lus and fracture toughness 185.2 MPa,91.1 GPa and 5.5 MPa·m^1/2 ,respectively.The improvement effects from the PIP-SiC interphase modified coating are attributed to the transfer loading and prevention of etching by Si.

关 键 词：先驱体浸渍-裂解 SIC 界面改性 气相渗硅 CF/SIC 

分 类 号：TB332[一般工业技术—材料科学与工程]