摘要
以TiC、TiN、WC、钼粉、Cr_(3)C_(2)为硬质相原料,以镍粉和铬粉为黏结剂(添加总质量分数为25%,铬粉质量分数分别为0,2.5%,5.0%,7.5%),采用真空烧结工艺制备Ti(C,N)基金属陶瓷,研究了铬添加量对该金属陶瓷显微组织、力学性能和抗氧化性能的影响。结果表明:添加不同含量铬的Ti(C,N)基金属陶瓷晶粒均为芯-环结构,芯相为Ti(C,N),环形相为(Ti,W,Mo,Cr)(C,N)多元固溶体;随着铬添加量的增加,金属陶瓷晶粒尺寸明显变大,同时环形相的均匀性变差;随着铬添加量增加,金属陶瓷的硬度增加,抗弯强度降低,断裂韧度先升后降,当黏结相中铬质量分数为5.0%时综合力学性能最佳,抗弯强度、硬度和断裂韧度分别达到1829 MPa、90.5 HRA和11.57 MPa·m^(1/2)。当黏结相中铬质量分数为5.0%时,金属陶瓷的单位面积氧化质量增加量较未添加铬的低,在氧化过程中表面形成了含NiCr_(2)O_(4)和CrMoO_(4)的致密氧化膜,有效阻碍了氧元素的进一步扩散,提升了基体的抗氧化性能。
With TiC,TiN,WC,Mo powder,Cr_(3)C_(2) as bonded phase raw materials,nickel powder and Cr powder as binders(the total mass fraction was 25%,and the mass fraction of Cr powder was 0,2.5%,5.0%,7.5%),different Ti(C,N)-based cermets were prepared by vacuum sintering process.The effect of Cr addition on the microstructure,mechanical properties and antioxidant properties of the cermet was investigated.The results show that the grains of Ti(C,N)-based cermets with different Cr content all exhibited the core-ring structure,whose core phase was Ti(C,N)and ring phase was(Ti,W,Mo,Cr)(C,N)multivariate solid solution.With the increase of Cr addition,the cermet grain size became significantly larger,and the homogeneity of the ring phase deteriorated.With the increase of Cr addition,the hardness of the cermet increased,the flexural strength decreased,and the fracture toughness first increased and then decreased.When the mass fraction of Cr in the binder phase was 5.0%,the comprehensive mechanical properties of the cermet were the best with the flexural strength,hardness,and fracture toughness of 1829 MPa,90.5 HRA,and 11.57 MPa·m^(1/2),respectively.When the mass fraction of Cr in the binder phase was 5.0%,the oxidation mass increase per unit area of the cermet was lower than that without Cr addition,and the denser oxide film containing NiCr_(2)O_(4) and CrMoO_(4) was formed on the cerment surface during the oxidation process.The dense oxide film effectively impeded the further diffusion of the oxygen element and enhanced the antioxidant performance of the substrate.
作者
陈宇聪
谭健
黄婷
刘伟康
黄莺莺
吴炳昆
姚振华
CHEN Yucong;TAN Jian;HUANG Ting;LIU Weikang;HUANG Yingying;WU Bingkun;YAO Zhenhua(School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China;New Tobacco Products Engineering Center,China Tobacco Hubei Industrial Co.,Ltd.,Wuhan 430040,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第11期37-44,共8页
Materials For Mechanical Engineering
基金
国家自然科学基金青年基金资助项目(52001118)。
