聚丙烯腈预氧化纤维原位热解对TiCN基金属陶瓷微观结构和力学性能的影响

发布时间：2018-05-14 09:14

本文选题：TiCN金属陶瓷 + 聚丙烯腈预氧化纤维　；参考：《稀有金属材料与工程》2015年S1期

【摘要】：在N_2气氛下用热压烧结方法,在TiCN-NbC-Mo_2C-Ni基质中添加聚丙烯腈预氧化纤维(PAN)作为先驱体原位热解成碳纤维,成功制备得到了组成均匀的Ti CN基金属陶瓷,并研究了PAN添加量(0~25 vol%)对所制备金属陶瓷的微观结构及力学性能的影响。X射线衍射分析表明,随着PAN添加量的增多,热解产生的石墨相含量越来越高;当PAN添加量为25 vol%时,观察到明显的石墨相(002)衍射峰。用扫描电子显微镜在金属陶瓷的断口观察到了韧性窝、撕裂棱及纤维拔出等现象;而在纤维状物质表面上进行的能谱分析表明,其碳原子含量达到90.9 at%以上,说明PAN预氧化纤维热解成了碳纤维。实验表明,随着PAN添加量的增加,所得金属陶瓷的密度和相对密度均逐渐减小;硬度逐渐降低;而抗弯强度和断裂韧性都先增大后减小,当PAN添加量为15 vol%时其抗弯强度达到最大值(约为1020MPa),当PAN添加量为20 vol%时其断裂韧性达到最大值(约10.8 MPa·m1/2)。
[Abstract]:TiCN-based cermet with uniform composition was successfully prepared by in-situ pyrolysis of carbon fiber with polyacrylonitrile preoxidized fiber (pan) as precursor in TiCN-NbC-Mo_2C-Ni matrix by hot pressing sintering in N-2 atmosphere. The effect of the addition of PAN on the microstructure and mechanical properties of the cermet was studied. X-ray diffraction analysis showed that the content of graphite phase increased with the increase of PAN content, and the content of graphite phase increased with the addition of PAN to 25 vol.When the content of PAN was 25 vol%, the content of graphite phase increased with the increase of the content of PAN. The obvious diffraction peak of graphite phase was observed. On the fracture surface of cermet, the phenomena of ductile cavity, tearing edge and fiber pull-out were observed by scanning electron microscope, and the energy spectrum analysis on the surface of fibrous material showed that the carbon atom content was over 90.9 at%. The results show that PAN preoxidized fiber is pyrolyzed into carbon fiber. The experimental results show that the density and relative density of the cermet decrease with the increase of PAN content, the hardness decreases, and the flexural strength and fracture toughness increase first and then decrease. When the content of PAN is 15 vol%, the flexural strength reaches the maximum value (about 1020MPA ~ (-1) and the fracture toughness reaches the maximum (about 10.8 MPa / 1 / 2) when the PAN content is 20 vol%.
【作者单位】：中国地质大学国土资源部深部地质钻探技术重点实验室;清华大学新型陶瓷与精细工艺国家重点实验室;
【基金】：国家地质调查局地质大调查项目(1212010916026) 国家科技支撑计划(2011BAB03B08)
【分类号】：TG148

【相似文献】