摘要
研究1000~1200℃高温热暴露对多孔基体Al_(2)O_(3)/Al_(2)O_(3)陶瓷基复合材料性能的影响,结果表明:1000℃热暴露100 h对复合材料拉伸强度无影响,1100℃热暴露100 h后拉伸强度略有降低,1200℃热暴露100 h后拉伸强度明显降低。进一步研究1200℃不同热暴露时长对Al_(2)O_(3)/Al_(2)O_(3)复合材料、氧化铝纤维及氧化铝基体性能的影响,并采用光学显微镜、SEM对试样的微观形貌进行表征。结果表明:1200℃热暴露100 h对氧化铝纤维的性能影响较小,但对氧化铝基体的影响较大,1200℃热暴露仅10 h后,氧化铝基体的孔隙率明显降低,密度明显增加;从基体断口的SEM形貌可以看出,随着1200℃热暴露时间的增加,氧化铝基体中的晶粒尺寸逐渐增大,基体发生进一步的烧结,相应地,从Al_(2)O_(3)/Al_(2)O_(3)复合材料的断口形貌可以看出,纤维拔出长度及数量也明显减少;高温热暴露后复合材料性能的降低主要缘于材料中氧化铝基体的进一步烧结,多孔基体的致密化降低了其对复合材料的增韧效果。
The effect of thermal exposure at 1000℃to 1200℃on the properties of porous matrix Al_(2)O_(3)/Al_(2)O_(3) ceramic matrix composites was studied.The results show that the thermal exposure at 1000℃for 100 h has no effect on the tensile strength of the composites.After 100 h at 1100℃,the tensile strength of the composites decreases slightly,and after 100 h at 1200℃,the tensile strength of the composites decreases obviously.The effects of different thermal exposure durations at 1200℃on the properties of Al_(2)O_(3)/Al_(2)O_(3) composites,alumina fibers and alumina matrix are further studied,and the micro morphologies of the samples are characterized by optical microscopy and SEM.The results show that the thermal exposure at 1200℃for 100 h has little effect on the performance of alumina fiber,but has a great effect on the alumina matrix.After the thermal exposure at 1200℃for only 10 h,the porosity of alumina matrix is significantly reduced and the density is significantly increased.It can be seen from the SEM morphology of the matrix fracture that with the increase of thermal exposure time at 1200℃,the alumina grain size of the matrix gradually increases and the matrix is further sintered.Correspondingly,it can be seen from the fracture morphology of the Al_(2)O_(3)/Al_(2)O_(3) composite that the length and number of fibers pulled out also decrease significantly.The degradation of the properties of the composites after high temperature thermal exposure is mainly due to the further sintering of alumina matrix,and the densification of porous matrix reduces the toughening effect of the composites.
作者
杨瑞
陈易诚
邓杨芳
孙世杰
赵文青
杨金华
焦健
YANG Rui;CHEN Yicheng;DENG Yangfang;SUN Shijie;ZHAO Wenqing;YANG Jinhua;JIAO Jian(National Key Laboratory of Advanced Composites,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Key Laboratory of Advanced Corrosion and Protection for Aviation Materials,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;AECC Sichuan Gas Turbine Establishment,Chengdu 610500,China)
出处
《航空材料学报》
CAS
CSCD
北大核心
2023年第2期1-8,共8页
Journal of Aeronautical Materials
关键词
热暴露
氧化铝
陶瓷基复合材料
拉伸强度
thermal exposure
alumina
ceramic matrix composite
tensile strength
