摘要
氧化铝纤维增强陶瓷基复合材料具有力学性能好、高温抗氧化、耐腐蚀、介电性能优异等特点,可用做于天线罩耐高温透波功能材料。以氧化铝纤维为增强体,以氧化铝浆料、莫来石溶胶为基体,磷酸镧作为界面层材料,制备出了氧化铝纤维增强陶瓷基复合材料,并对复合材料在室温以及1200℃的拉伸强度进行表征,同时通过扫描电镜观察其破坏规律。结果表明:引入LaPO_(4)界面相的复合材料,室温下的拉伸强度为148.3MPa,1200℃下的拉伸强度为129.6MPa,与无界面相复合材料拉伸强度相比分别提高了20.1%和24.9%。无界面相的氧化铝纤维增强陶瓷基复合材料断口平整,呈现脆性断裂,存在LaPO_(4)界面相的氧化铝纤维增强陶瓷基复合材料断口有大量纤维拔出,表现出韧性断裂特征。含有LaPO_(4)界面的复合材料在10GHz、常温下介电常数均值为5.77,介电损耗为0.0018。在1300℃下材料的介电常数均值为6.18,介电损耗为0.0020。相对于常温条件,介电常数和介电损耗的变化率分别为7.10%和11.1%,满足变化率小于15%的要求,有望用于透波复合材料领域。
Alumina fiber reinforced ceramic matrix composites are characterized by good mechanical properties,high temperature oxidation resistance,corrosion resistance and excellent dielectric properties.This material can be used as a kind of high temperature-resistant wave-transmitting functional material for radome.Taking Al2O3 and mullite slurry as basement,Al_(2)O_(3) fiber as reinforcement,and LaPO_(4) as interface,Al_(2)O_(3)/Al_(2)O_(3)composite is fab-ricated by repeating infiltration and high temperature treatment process.And then,the tensile strength of the composites at room temperature and 1200℃are measured,and the SEM is employed in observing the fracture microstructure.The tensile strength of Al_(2)O_(3)/Al_(2)O_(3) composites with LaPO_(4) interface at room temperature is 148.3 MPa,and increment of tensile strength is 20.1%in comparison with Al_(2)O_(3)/Al_(2)O_(3) composites without in-terface.The tensile strength of Al_(2)O_(3)/Al_(2)O_(3) composites with LaPO_(4) interface at 1200℃is 129.6 MPa,and its increment is 24.9%in comparison with Al_(2)O_(3)/Al_(2)O_(3) composites without LaPO_(4) interface.The SEM observation shows that the fracture surface of the composite without LaPO4 interface is smooth at crack,and brittle in frac-ture.A large number of fibers are pulled out in the fracture of alumina fiber reinforced ceramic matrix composites with LaPO_(4) interface phase,showing ductile fracture characteristics.The average dielectric constant of the com-posite material is 5.77 and the dielectric loss is 0.0018 when the frequency is 10 GHz and RT;the average dielec-tric constant of the material at 1300℃is 6.18 with the dielectric loss is 0.0020.The change rate of electric con-stant and dielectric loss is 7.10%and 11.1%respectively,meeting the needs of change rate<15%,and such a material is expected to be used in the field of wave-transparent composite materials.
作者
钟文丽
刘一畅
秦高磊
马新洲
叶冉冉
张剑
吕毅
ZHONG Wenli;LIU Yichang;QIN Gaolei;MA Xinzhou;YE Ranran;ZHANG Jian;LYU Yi(Aerospace Institute of Advanced Materials&Processing Technology,Beijing 100074,China)
出处
《空军工程大学学报》
CSCD
北大核心
2024年第3期28-35,共8页
Journal of Air Force Engineering University
关键词
氧化铝
磷酸镧界面
复合材料
拉伸强度
透波率
salumina
lanthanum phosphate interface
composite
tensile strength
transmissivity
作者简介
钟文丽(1985-),女,江西抚州人,高级工程师,博士,研究方向为材料科学与工程。E-mail:94120347@qq.com。
