反应熔渗C/C-SiC-ZrC复合材料的界面特征及其力学性能  

Interface characteristics and mechanical properties of reactive melt infiltrated C/C-SiC-ZrC matrix composites

作　　者：丁家鑫 陈招科[1] 王铎[1] 熊翔[1] DING Jiaxin;CHEN Zhaoke;WANG Duo;XIONG Xiang(Science and Technology on High Strength Structural Materials Laboratory,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻质高强结构材料重点实验室,长沙410083

出　　处：《复合材料学报》2024年第11期6195-6205,共11页Acta Materiae Compositae Sinica

基　　金：总装重点实验室基金(6142907200301);国家自然科学基金面上项目(52072410)。

摘　　要：C/C-SiC-ZrC复合材料作为一种极具前景的热防护材料,在航空航天领域均有广泛应用。但是反应熔渗法(Reactive melt infiltration,RMI)制备的C/C-SiC-ZrC复合材料却存在力学性能偏低的缺点,成为制约其发展应用的主要因素。为了改善C/C-SiC-ZrC基复合材料的纤维损伤和力学性能,通过化学气相沉积(Chemical vapor deposition,CVD)在碳纤维针刺坯体中引入了300 nm厚的热解碳(Pyrolysis carbon,PyC)界面、300 nm厚的PyC/SiC双层界面和100 nm、300 nm、800 nm厚的(PyC+SiC)共沉积界面,再采用RMI制备出C/C-SiC-ZrC复合材料。采用XRD、SEM、电子探针(EPMA)和TEM等分析手段研究了C/C-SiC-ZrC复合材料的物相、微观形貌、元素分布及RMI后C/C-SiC-ZrC复合材料的界面损伤情况,并采用三点弯曲试验评估了RMI后试样的弯曲性能。结果表明:界面的引入不仅起到了对纤维的保护作用,同时也改善了纤维和基体间的结合状态,极大地避免了反应熔渗对碳纤维的侵蚀;PyC界面对纤维的保护作用有限,而PyC/SiC双层界面的保护作用最好;界面类型和界面厚度对复合材料力学性能产生重要影响,当界面厚度相同时,含(PyC+SiC)共沉积界面复合材料和含PyC/SiC双层界面复合材料的抗弯强度分别为162.80 MPa和208.58 MPa,均优于含PyC界面的复合材料;随(PyC+SiC)共沉积界面厚度的增大,复合材料的力学性能呈现先上升后下降的趋势。C/C-SiC-ZrC matrix composites are widely used in aerospace field as a kind of promising thermal protection materials.But C/C-SiC-ZrC matrix composites prepared by reactive melt infiltration(RMI)have the disadvantage of low mechanical properties,which is the main factor restricting its development and application.In order to improve the fiber damage and mechanical properties of the C/C-SiC-ZrC matrix composites,300 nm pyrolysis carbon(PyC)interface,300 nm PyC/SiC double-layer interface,and 100 nm,300 nm,and 800 nm(PyC+SiC)co-deposited interfaces were introduced into carbon fiber needled preform by chemical vapor deposition(CVD);and then the C/C-SiC-ZrC matrix composites were prepared by RMI.The phase composition,micro-morphology,element distribution and interface damage were investigated by XRD,SEM,electron probe(EPMA)and TEM,and the mechanical properties of the composites after RMI were evaluated by three-point bending tests.The results show that the introduction of the interfaces not only protect the fibers,but also improve the bonding state between the fibers and the matrix,which greatly avoids the erosion of the carbon fibers by RMI.The PyC interface provided limited protection to the fibers,while the PyC/SiC double-layer interface provided the best protection.The interface type and interface thickness have an important effect on the mechanical properties of the composites.When the interface thickness is the same,the bending strength of the composites with(PyC+SiC)co-deposited interface and the composites with PyC/SiC double-layer interface are 162.80 MPa and 208.58 MPa,respectively,which are superior to those of the composites containing the PyC interface.With the increase of(PyC+SiC)co-deposited interface thickness,the mechanical properties of the composites show the trend of increasing and then decreasing.

关 键 词：C/C-SiC-ZrC复合材料 界面 反应熔渗 界面损伤 弯曲强度 

分 类 号：TB332[一般工业技术—材料科学与工程]