梯度结构Al_2O_3-(W,Ti)C-TiN-Mo-Ni纳米金属陶瓷刀具材料的设计及制备  

Design and Fabrication of Al_2O_3-(W,Ti)C-TiN-Mo-Ni Nano-composite Cermet Tool Materials with Graded Structures

作　　者：倪秀英 赵军[1] 孙加林[1] 李洪江 侯冠明 田源 NI Xiu-ying;ZHAO Jun;SUN Jia-lin;LI Hong-jiang;HOU Guan-ming;TIAN Yuan(School of Mechanical Engineering,Shandong University,Jinan 250061,China;School of Transportation,Ludong University,Yantai 264025,Shandong,China;3Lovol Heavy Industry Co.,Ltd.,Weifang 261206,Shandong,China;School of Mechanical&Automotive Engineering,Qilu University of Technology,Jinan 250061,China)

机构地区：[1]山东大学机械工程学院,济南250061 [2]鲁东大学交通学院,山东烟台264025 [3]雷沃国际重工股份有限公司,山东潍坊261206 [4]齐鲁工业大学机械与汽车工程学院,济南250061

出　　处：《材料工程》2018年第2期50-56,共7页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51475273)

摘　　要：基于对高速硬切削时刀具应力和温度分布,以及刀具内部疲劳裂纹扩展仿真分析,提出一个组分含量分布和微观结构具有梯度特征的设计模型。通过韧性相的添加和梯度结构的引入,实现疲劳裂纹扩展速率的减缓,从而提高刀具寿命。采用二阶段热压烧结工艺制备出具有梯度结构的Al_2O_3-(W,Ti)C-TiN-Mo-Ni纳米复合刀具材料,并对其微观结构和力学性能进行研究。结果表明:所制备的梯度结构金属陶瓷材料表层硬度、内层的断裂韧度和抗弯强度分别达到19.258GPa,10.015MPa·m^(1/2)和1017.475MPa,满足高速硬切削刀具的性能要求。材料的断口出现韧窝和黏结相撕裂形成的断裂棱,有利于断裂韧度和抗弯强度的增强,从而提高刀具抗疲劳裂纹扩展能力。Based on the analysis on temperature and stress distributions,as well as fatigue crack prop-agation in cutting tools,a model for designing compositional distribution and microstructure with gra-ded characteristics was proposed.The addition of ductile phase and the introduction of the graded structure are beneficial to slow down the fatigue crack propagation rate and improve tool life.Al2 O3-(W,Ti)C-TiN-Mo-Ni nano-composite tool material with graded structures was fabricated via two stage hot pressing sintering process,and the microstructure and mechanical properties were studied.The results show that the surface hardness,fracture toughness of inner layer and bending strength of the cermet with sintered gradient structure reach 19.258GPa,10.015MPa·m1/2 and 1017.475MPa,respectively.The performance requirements to cutting tools were met.The dimple cleavage and torn edge of the binding phase in the fracture surfaces can be beneficial to the improvement of the frac-ture toughness and bending strength,so the resistance to fatigue crack propagation of tools is im-proved.

关 键 词：梯度结构 金属陶瓷 疲劳裂纹 结构设计 热压烧结 

分 类 号：TQ174[化学工程—陶瓷工业]