La2O3添加量对Ti(C,N)-WC-Mo2C-Ni-Co金属陶瓷组织结构和力学性能的影响
Effect of La2O3 additions on microstructure and mechanical properties of Ti(C,N)-WC-Mo2C-Ni-Co cermets
邱昊 1李小强 1江晨阳 1潘存良 1屈盛官1
作者信息
- 1. National Engineering Research Centre of Near-net-shape Forming Technology for Metallic Materials,South China University of Technology,Guangzhou 510640,China
- 折叠
摘要
稀土元素被认为是可以有效改善TiCN基金属陶瓷性能的添加剂,但其在高Mo2C含量下的效果尚未得到深入研究.本研究采用真空热压烧结技术,在1500℃下制备了不同La2O3含量的Ti(C,N)-WC-Mo2C-Cr3C2-Ni-Co金属陶瓷,其中Mo2C含量为12 wt.%.对不同La2O3添加量(0.5 wt.%、1.0 wt.%、1.5 wt.%和2.0 wt.%)对Ti(C,N)基陶瓷显微组织和力学性能的影响进行了参数化分析.结果表明,当La2O3含量增加到1.0 wt.%时,芯相的比例增加,脆壳相的比例减少;在陶瓷相晶界上形成的纳米结构,有效抑制了壳相组织的异常长大,这使得金属陶瓷的脆壳相变薄,硬质相颗粒细化,从而提高了其硬度和断裂韧性等力学性能.当La2O3的添加量从1.5 wt.%增加到2.0 wt.%时,La2O3团聚形成直径约100 nm的较大颗粒,大幅度降低了金属陶瓷的力学性能.当La2O3添加量为 1.0 wt.%时,Ti(C,N)基陶瓷的综合力学性能最佳,其维氏硬度和断裂韧性分别为16.55 GPa和6.14 MPa·m1/2.本研究有助于进一步揭示稀土氧化物对高Mo2C含量Ti(C,N)基陶瓷芯壳结构和力学性能的影响.
Abstract
Rare earth elements were considered alternative additives beneficial to the TiCN based cermets,but their effect with high content Mo2C has not been thoroughly investigated.In this study,Ti(C,N)-WC-Mo2C-Cr3C2-Ni-Co cermets containing 12 wt.%Mo2C doped with different contents of La2O3 were prepared by vacuum hot-press sintering at 1500℃.Parametrical analysis on La2O3 addition(0,0.5 wt.%,1.0 wt.%,1.5 wt.%,and 2.0 wt.%)was conducted,in terms of microstructure and mechanical properties of Ti(C,N)based cermets.Experimental results show that when the content of La2O3 increases from 0 to 1.0 wt.%,the ratio of core phase increases while the ratio of brittle rim phase decreases.Nanostructure is formed on the grain boundary of ceramic phase,which effectively inhibits the abnormal growth of rim structures.This can thin the brittle shell,coarsen the core phase,and refine the grains,thus improving its mechanical properties,including hardness and fracture toughness.When the addition amount of La2O3 increases from 1.5 wt.%to 2.0 wt.%,it will aggregate to form larger particles of about 100 nm,which sharply reduces its mechanical properties.The optimal La2O3 addition is 1.0 wt.%,in which Ti(C,N)-based cermets show the optimal comprehensive mechanical properties:the Vickers hardness and fracture toughness are 16.55 GPa and 6.14 MPa·m1/2,respectively.This work provides further knowledge about the effect of rare earth on the core-rim structure and mechanical properties of Ti(C,N)-based cermets with high Mo2C contents.
关键词
碳氮化钛基金属陶瓷/稀土/氧化镧/芯壳结构/断裂韧性Key words
Ti(C,N)-based cermets/earth elements/La2O3/core-rim structure/fracture toughness引用本文复制引用
基金项目
National Natural Science Foundation of China(51474108)
Natural Science Foundation of Guangdong Province,China(208081725043)
Innovationdriven Development Science and Technology Project of Economic Development District of Yichun,China(1203)
出版年
2023
NETL
NSTL
万方数据