连续碳化硅纤维增强钛基(SiCf/Ti)复合材料的制备技术及界面特性研究综述

连续碳化硅纤维(SiCf)由于具有比强度、比模量高,耐磨性、热稳定性好等性能优点,常作为增强体制备SiC纤维增强钛基复合材料。与钛合金基体相比,其具有密度更低、强度更高、疲劳蠕变性能大幅提升等优点,但横向性能却明显下降。因此,该类材料常被设计制作成单向增强性部件,广泛应用在航空航天等领域,如发动机的传动轴、整体叶环、盘类及风扇叶片等多种复合材料的结构件。碳化硅纤维增强钛基复合材料的性能主要由碳化硅纤维的性能、基体性能及纤维与基体之间的结合界面性能决定。目前批量生产的SiC纤维性能较差,界面结合状态与复合材料性能之间关系的研究开展较少,还不能为钛基复合材料构件设计提供足够的数据支持。因此,近年来研究者们主要从SiCf/Ti基复合材料力学行为的研究角度出发,探究不同基体及纤维类型、复合材料制备工艺方法、界面特性及产物对SiCf/Ti基复合材料界面结合力及破坏机制的影响,获得了大量有价值的数据,以期开发出成本低、产物稳定性好、可批量生产SiCf/Ti基复合材料的制造工艺方法。目前较为成熟的碳化硅纤维有英国DERA-Sigma公司提供的Sigma系列SiCf及美国Textron公司提供的SCS系列SiCf,后者强度最高达到6 200 MPa。SiCf/Ti基复合材料的制备工艺包括金属箔-纤维-金属箔工艺(FFF)、单层带工艺(MT)、基体-涂层纤维工艺(MCT)等,制备复合材料的工艺根据零部件的用途来定,FFF适用于制备板材等大尺寸构件,MCT适用于制备叶环、轴、管、叶片等复杂结构件。界面是增强体与基体之间的纽带和桥梁,界面结构设计、界面反应控制及反应产物均影响着界面的力学特性。在SiCf/Ti基复合材料的纤维和基体之间添加过渡层能够减缓它们之间的相互扩散及化学反应,过渡层选用反应层和惰性涂层组成的双层涂层较好。界面反应产物受涂层成分、基体组织、复合和热处理工艺、环境因素等的影响,增强纤维及基体性能、优选制备工艺、控制界面反应及产物有利于提高复合材料的力学性能。本文总结了连续SiC纤维(SiCf)增强钛基复合材料的应用研究现状,详述了SiCf/Ti基复合材料的钛合金基体材料、SiCf的种类及性能,SiCf与SiCf/Ti基复合材料的制备方法,分析了SiCf/Ti基复合材料界面结构设计及反应产物,阐明了界面力学特性与复合材料性能的关系,指出国内SiCf/Ti基复合材料发展的重点应放在高性能SiC纤维的研究与开发、界面层设计及界面与性能的关系以及复合材料分析检测手段三个方面,为SiCf/Ti基复合材料的制备及其今后的实际应用提供了参考。

A Review of the State-of-Art Preparation Techniques and Interface Characteristics of Continuous-silicon-fiber-reinforced Titanium Matrix(SiCf/Ti) Composites

Continuous SiC fiber having advantages of high specific strength,high specific modulus,strong wear resisitance and good heat stability is the reinforcement of SiC fiber reinforced titanium matrix composite.SiCf/Ti matrix composite comparing with titanium alloy matrix has strengths of lower density,higher strength,more excellent fatigue and creep deformation resistance,but its transverse property decreases obviously.Therefore,SiCf/Ti matrix composite is used to design unidirectional reinforced struc-tures,such as transmission shafts,blings,blisks and fan blades,and broadly applys to aerospace fields. SiCf/Ti matrix composite's properties depend on the properties of SiCf,matrix and the interface bonding strength between SiCf and matrix.Duing to the poor properties of batch production SiCfand the less researches of relation between interface bonding state and composite performances,there are not sufficient data to support the design of titanium matrix composite structure at present. Therefore,reseachers have studied on the various types of matrix and fiber,the techniques of composite preparation,the effect of in-terface feature and production on interface bonding force and interface failure of composites in recent years.The data from studies probably optimize the technique to produce SiCf/Ti matrix composite with low cost,good stability and feasible volume production. Mature SiCfincludes the Sigma series from British DERA-Sigma company and the SCS series with strength of 6 200 MPa from USA Textron company.The prepartion techniques of SiCf/Ti matrix composite include foil-fiber-foil,mono-layer technique and matrix-coating fiber technique,etc.The usages of parts determine on the techniques of composite preparation.FFF is applied to large size structures as flat sections,and MCT is utilized to complex structures as blings,shafts,pipes and blades.Interface is the bridge con-necting reinforcement and matrix.Interfacial design,interfacial reaction control and reaction products have impact on interfacial me-chanical characteristic.Adding transition layer with a better method of selecting double layer consisted of reaction and inert coating layer between fiber and matrix slows down the diffusion and chemical reaction.Interface reaction products are influenced by coating composition,matrix texture,preparation and thermal treatment and environment,etc.Reinforcing fiber and matrix properties,opti-mizing preparation techniques,controlling interface reaction and products are beneficial to enhance mechanics properities of compo-site. In this paper,the application and research status of these SiCf/Ti matrix composites are reviewed,the choice of the titanium al-loys matrix,the different types of SiC fibers and the fabrication of the composites are also summarized systematically.The design of SiCf/Ti matrix composites interface and its reaction products are analyzed.The relationship between the interfacial mechanical pro-perties and the composite properties is illustrated.And finally,the paper points out that the future development of continuous SiC fiber reinforced titanium matrix composite should be focused on the high-performance SiC fiber,the design of interface layer,the re-lation of interface and property,and the new composites detection and analysis machines,providing reference for the future work.