改性碳纤维含量对Ti(C,N)基金属陶瓷组织结构和力学性能的影响  

Influence of Modified Carbon Fibers Content on Microstructure and Mechanical Properties of Ti(C,N)-based Cermets

作　　者：张佩[1] 孙万昌[1] 李攀[1] 张磊[2] 

机构地区：[1]西安科技大学材料科学与工程学院,陕西西安710054 [2]中国船舶重工集团公司第十二研究所陕西兴平,713102

出　　处：《热加工工艺》2015年第10期149-152,156,共5页Hot Working Technology

基　　金：陕西省科技攻关项目(2014K08-09);国家自然科学基金资助(50172023);榆林市产学研科技计划项目(2012);陕西省教育厅专项计划资助(11JK0824)

摘　　要：以Ti C、Ti N微米级粉末为主要原料,Ni、Co为金属粘结剂,添加改性短碳纤维(Cf)为增强相,采用无压结技术制备了Ti(C,N)基金属陶瓷,利用扫描电镜分析了Ti(C,N)基金属陶瓷的显微组织、断口形貌,通过维氏硬度法、三点弯曲法测试了Ti(C,N)基金属陶瓷的硬度和抗弯强度。结果表明:碳纤维表面镀镍后,镍磷(Ni-P)镀层表面平整致密,均匀包覆于碳纤维表面,且镀层与纤维结合紧密;添加改性碳纤维后,Ti(C,N)基金属陶瓷断裂方式以穿晶断裂为主,断面整体起伏较大,断口形貌主要表现为大量穿晶断裂留下的大块硬质相颗粒,少量沿晶断裂留下的凹坑以及小块硬质相颗粒和粘结相金属塑性变形形成的撕裂棱;Ti(C,N)基金属陶瓷组织形貌具有典型的"芯-壳"组织结构;当碳纤维添加量为4wt%时,材料抗弯强度和硬度达到最大值,分别为386.42、33.96 GPa。Ti（C,N）-based cermets were successfully prepared by pressureless sintering technology,with Ti C,Ti N micron powders as the main raw materials,Ni,Co as binder metal,and modified short carbon fibers as reinforcement.The microstructure,fracture morphology and phase structure were investigated by scanning electron microscopy（SEM）.The effects of the addition of modified carbon fibers on the microstructure and mechanical properties of Ti（C,N）-based cermets were examined by Vickers hardness measurement and three-point bending method separately.The results show that the surface of modified carbon fiber is smoothly,the Ni-P coating on the carbon fiber is dense and uniform.The thickness of Ni-P coating could be controlled and the Ni-P coating combines with the fiber tightly.After adding the modified carbon fibers,the main fracture mode of Ti（C,N）-based cermets is transgranular fracture,leaving a large undulating fracture surface.The fracture surface shows lots of bulk hard phase particles left by transgranular fractures,a small amount of pits left by intergranular fracture and some tearing edges are formed by plastic deformation of metal binders.The morphology of Ti（C,N）-based cermets exhibit a typical ＂core-rim＂ structure.When the modified carbon fiber content is 4wt%,the bending strength and hardness of Ti（C,N）-based cermets reach the maximum of 386.42 MPa and 33.96 GPa,respectively.

关 键 词：TI(C N)基金属陶瓷 强韧化 碳纤维 化学镀镍 显微组织 力学性能 

分 类 号：TG148[一般工业技术—材料科学与工程]