离心-凝胶注模成型技术制备梯度碳纤维/HA复合材料  

Preparation of Gradient Carbon Fiber / HA Composites by Centrifugal-gelcasting Technology

作　　者：李强[1,2] 于景媛[1] 李振超[1] 商剑 石萍[1] 孙旭东[2] 

机构地区：[1]辽宁工业大学材料科学与工程学院,锦州121001 [2]东北大学材料与冶金学院,沈阳110004

出　　处：《人工晶体学报》2016年第3期826-833,共8页Journal of Synthetic Crystals

基　　金：国家自然科学基金(51405215);辽宁省自然科学基金(2014020111);辽宁省高等学校杰出青年学者成长计划(LJQ2013067)

摘　　要：以经过低温氧化和提拉HA溶胶改性处理的碳纤维为增强体,采用离心-凝胶注模成型技术制备梯度碳纤维/HA复合材料。观察了碳纤维改性处理后的形貌,研究了碳纤维/HA浆料的特性,以及浆料的凝胶固化过程。分析了离心转数、碳纤维含量对梯度复合材料生坯密度梯度的影响。观察了烧结后梯度复合材料的显微组织,并测量了不同烧结温度和碳纤维分布的HA复合材料的抗弯强度和断裂韧性。研究结果表明改性处理碳纤维表面形成一层致密的、结合性能较好的膜层,烧结后可以很好地连接基体和碳纤维。在p H=9,分散剂含量为5wt%,浆料固相含量为40wt%,碳纤维含量为2wt%时,碳纤维/HA浆料具有良好的分散性和稳定性。当催化剂和引发剂含量均为0.9wt%时,起始凝胶和终止固化时间与离心成型工艺相匹配。当离心转数为1000 r/min,碳纤维含量为2wt%时,离心-凝胶注模成型所得试样具有良好的密度梯度,1100℃烧结2 h后,该复合材料的抗弯强度达到最大值101.7 MPa;断裂韧性为1.98 MPa·m1/2,分别比干压成型制备的均匀碳纤维/HA复合材料提高了29.7%和25.3%。The carbon fiber modified after oxidation at low temperature and dip in the HA-sol was used as reinforcement to prepared gradient carbon fiber / HA composites using centrifugal-gelcasting method. The morphology of modified carbon fiber was observed. The characteristic and gel-solidification process of carbon fiber / HA slurries were studied. The effects of centrifugal rotation speed and carbon fiber content on green density difference of HA composites were analyzed. The microstructure of sintered compacts was observed and the bending strength and fracture toughness of different carbon fiber / HA composites were measured. The results show the surface of modified carbon fibers have a compact and fastness HA layer,which can better contact the carbon fibers and HA matrix. The 40wt% carbon fibers / HA slurries have good dispersion and stability at p H of 9 and the dispersant of 5wt%. At the amount of initiator and catalyst of 0. 9wt%,the gelcasting process of carbon fiber / HA slurries meet with centrifugal process. The carbon fibers / HA slurries with 2wt% carbon fiber centrifuged at 1000 r / min to form good gradientdistribution of green density. After sintered at 1100 ℃ for 2 h,the bending strength and fracture toughness of the gradient composites are 101. 7 MPa and 1. 98 MPa·m1 /2,respectively,which are 29.7% and 25. 3% more than those of the uniform carbon fibers / HA composites prepared by drying pressing method.

关 键 词：离心-凝胶注模 梯度碳纤维/HA复合材料 浆料特性 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]