TiC/NbC添加量对铁基复合材料显微组织及力学性能的影响

Effect of TiC/NbC Content on Microstructure and Mechanical Properties of Iron-based Composite Materials

将不同添加量的TiC/NbC陶瓷颗粒(质量分数分别为50%、33.33%、25%、20%、16.67%)加入到铁基体中,采用放电等离子体烧结(SPS)技术制备了陶瓷颗粒增强铁基复合材料。通过扫描电子显微镜(SEM)以及能谱仪(EDS)对烧结试样的微观组织形貌进行表征,并对其相对密度和力学性能进行测试。结果表明,含16.67%TiC/NbC陶瓷颗粒的烧结试样相对密度最大,达96.78%,且拥有较高的维氏硬度和弯曲强度,分别为300 HV和400 MPa;试样断口表现出明显的脆性断裂特征。SPS快速烧结技术可使TiC/NbC陶瓷颗粒均匀分散在铁基体中,且增强体和铁基体界面结合良好。少量TiC/NbC陶瓷颗粒即可显著细化基体组织,增强铁基复合材料强度和硬度;随着TiC/NbC陶瓷颗粒含量的进一步增加,其对基体组织的细化作用减弱。

TiC/NbC ceramic particles(mass fractions of 50%,33.33%,25%,20%and 16.67%)were added to the iron matrix,and ceramic particle reinforced iron-based composite materials were prepared by spark plasma sintering(SPS).The microscopic morphology of the sintered samples were characterized by scanning electron microscope(SEM)and energy dispersive spectrometer(EDS),and their relative density and mechanical properties were tested.The results show that the iron-based composite material with 16.67%TiC/NbC ceramic particles has the highest relative density of 96.78%,and high Vickers hardness and flexural strength of 300 HV and 400 MPa,and its fracture shows obvious brittle fracture characteristics.SPS rapid sintering technology can make TiC/NbC ceramic particles uniformly dispersed in the iron matrix,and the interface between the reinforcement phase and the iron matrix is well combined.A small amount of TiC/NbC ceramic particles can significantly refine the matrix microstructure and enhance the strength and hardness of the iron-based composite materials.With the further increase of the content of TiC/NbC ceramic particles,their refinement effect on the matrix microstructure is weakened.