摘要
碳化硅纤维增强碳化硅复合材料(SiC_(f)/SiC)是制造下一代航空发动机热结构件的关键材料,中等温度(~800℃)下,SiC_(f)/SiC的蠕变断裂时间t_(u)显著下降。为此,研究了平纹编织SiC_(f)/SiC(2D-SiC_(f)/SiC)在空气中500~1000℃的蠕变性能及损伤机制,应力水平为100~160 MPa。利用SEM、TEM和EDS分析了断口形貌、微观组织和化学成分。结果表明:2D-SiC_(f)/SiC的t_(u)与温度和应力水平有关。相同温度下,2D-SiC_(f)/SiC的t_(u)随着应力增加而变短。当温度为800℃、蠕变应力大于基体开裂应力(PLS)时,2D-SiC_(f)/SiC发生中温脆化现象,其t_(u)下降。2D-SiC_(f)/SiC的中温脆化机制为基体开裂、BN界面氧化和SiO_(2)替代BN界面导致的强界面/基体结合。2D-SiC_(f)/SiC的t_(u)与应力在对数坐标下呈线性关系,且在过渡应力时发生线性转变,过渡应力与PLS一致。提高PLS能够有效提高SiC_(f)/SiC的t_(u)。
Silicon carbide fiber reinforced silicon carbide composites(SiC_(f)/SiC)have great potential to be used in the thermal structure of next-generation aero-engines.The creep rupture time t_(u) of SiC_(f)/SiC significantly reduced at intermediate temperatures(~800℃).Therefore,this paper investigated the creep rupture behaviors of a plain weave SiC_(f)/SiC(2D-SiC_(f)/SiC)at 500℃,800℃and 1000℃with stresses of 100 MPa to 160 MPa in air.The morphology,microstructure and compositions of the crept specimens were observed by scanning electron microscopy,transmission electron microscopy and an energy dispersive analysis system.The results show that the t_(u) of 2DSiC_(f)/SiC is closely related to the applied temperatures and stresses.At the same temperature,t_(u) decreases with the increasing stresses at constant temperatures.When the temperature is 800℃and the stress is greater than the proportional limit stress(PLS),embrittlement takes place for the 2D-SiC_(f)/SiC,which means the t_(u) and the total creep strain are much shorter than those at 500℃and 1000℃.The embrittlement mechanisms involve matrix cracking,oxidization of BN and formation of strong fiber/matrix interphase bonding by the filling of SiO_(2),as well as for the 2DSiC_(f)/SiC at intermediate temperatures.t_(u) vs.the applied stress follows linear relationship in logarithmic axis,whose transition appears when the applied stress equals to PLS.
作者
朱思雨
张巧君
洪智亮
荆开开
管皞阳
程赞粼
刘永胜
王波
张程煜
ZHU Siyu;ZHANG Qiaojun;HONG Zhiliang;JING Kaikai;GUAN Haoyang;CHENG Zanlin;LIU Yongsheng;WANG Bo;ZHANG Chengyu(NPU-SAS Joint Research Center,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Xi'an Aviation Brake Technology Co.,Ltd.,Xingping 713106,China;AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China;Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi’an 710072,China;School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2023年第1期464-471,共8页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51572224,U2241239)
高等学校学科创新引智计划(BP0820014)
国家重点研发计划(2017YFB1103504)。
