MI SiC_(f)/SiC-SiYBC复合材料的蠕变性能及损伤机理  

Creep Properties and Damage Mechanisms of SiC_(f)/SiC-SiYBC Prepared by Melt Infiltration

作　　者：张立 管皞阳 郑琪宁 洪智亮 王佳璇 邢宁 李玫[1] 刘永胜[1] 张程煜[1] ZHANG Li;GUAN Haoyang;ZHENG Qining;HONG Zhiliang;WANG Jiaxuan;XING Ning;LI Mei;LIU Yongsheng;ZHANG Chengyu(Key Laboratory of Ultra-High Temperature Structural Composites,Northwestern Polytechnical University,Xi’an 710072,China;AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China)

机构地区：[1]西北工业大学超高温结构复合材料重点实验室,西安710072 [2]中国航发商用航空发动机有限责任公司,上海200241

出　　处：《无机材料学报》2025年第1期23-30,共8页Journal of Inorganic Materials

基　　金：国家自然科学基金(U2241239);国防科技基础加强计划(2023-JCJQ-LB-071)。

摘　　要：随着航空发动机的服役环境日益严苛,SiC_(f)/SiC在高温空气/水氧环境中的服役温度和应力亟需提升。为此,研究人员尝试采用自愈合基体改性的方法提升SiC_(f)/SiC复合材料的抗氧化性能和抗蠕变性能。本工作研究了熔体渗透工艺(MI)制备的碳化硅纤维平纹布增强的SiYBC改性碳化硅复合材料(MISiC_(f)/SiC-SiYBC)在空气中的拉伸蠕变性能及损伤机理,蠕变温度为1300、1350和1400℃,应力为60~120 MPa。结果显示:在1300~1400℃范围内,MISiC_(f)/SiC-SiYBC的蠕变断裂时间(tu)与应力、温度密切相关,随温度或应力升高而降低。当蠕变应力高于比例极限应力(σ_(PLS))时,基体开裂,氧气会进入材料内部侵蚀纤维和BN界面,使其发生氧化退化,大幅降低tu。此时由于基体完全开裂,载荷主要由纤维承担, tu受纤维的抗蠕变性能控制。当蠕变应力低于σ_(PLS)时, t_(u)较长,载荷由纤维和基体共同承担, tu则受纤维和基体两者的抗蠕变性能共同控制。随着温度从1300℃升高至1400℃,基体氧化物等物相填充界面间隙,导致界面黏结,促进裂纹张开和扩展。As aeroengines operate in gradually harsher service environments,enhancement of the service temperature and stress tolerance of SiC_(f)/SiC is in great demand to ensure its proper work in high-temperature air/water-oxygen environments.Previously,researchers have initiated efforts to modify the matrix through self-healing techniques to enhance the oxidation resistance and creep resistance of SiC_(f)/SiC composites,but whether it can be modified for more severe conditions remained unknown.Here,SiYBC modified SiC_(f)/SiC composites(MI SiC_(f)/SiC-SiYBC)were prepared by melt infiltration(MI),and their tensile creep properties and damage mechanisms in air at temperatures of 1300,1350,and 1400℃ with applied stresses ranging from 60 to 120 MPa were explored.The composites were reinforced with plain woven fabric of silicon carbide fibers,while the matrix was prepared by melt infiltration process.The results demonstrate that the creep rupture time(t_(u))is significantly influenced by stress and temperature,exhibiting a decrease with increasing temperature or stress.When test creep stress exceeds the proportional ultimate stress(σ_(PLS)),the matrix cracking facilitates oxygen ingress into the material,leading to erosion of the fiber and BN interfaces and subsequent oxidative degradation,which markedly reduces tu.As a result,the matrix is fully fractured,and the load is mainly supported by the fibers,whose creep resistance becomes the principal factor influencing performance.Conversely,when the creep stress is below σ_(PLS),t_(u) is extended,with the load being borne by the fibers and the matrix,which is controlled by the combined creep resistance of fibers and matrix.Additionally,as the temperature increases from 1300 to 1400℃,the generated oxides fill the gap of the matrix/fiber interface,enhancing interfacial bonding and facilitating crack propagation and growth.

关 键 词：SiCf/SiC-SiYBC 蠕变 氧化 损伤机制 

分 类 号：TB332[一般工业技术—材料科学与工程]