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采用真空热压烧结法制备两种成分的ZrB_2增强NbMo基复合材料:42.5%Nb+42.5%Mo+15%ZrB_2、42.5%Nb+42.5%Mo+10.5%ZrB~(2+)4.5%SiC(体积分数)。烧结工艺为温度1600℃,轴向应力30 MPa,保护气体为氩气,保温时间分为1 h和2 h。使用扫描电子显微镜、能谱分析仪和X射线衍射仪分析材料的微观结构和相组成,使用显微维氏硬度计和液压式万能试验机检测材料的力学性能。研究发现,ZrB颗粒均匀分布于NbMo固溶体中,在添加SiC的样品中有SiC的剩余以及MoSi_2相的生成。与无陶瓷相添加的样品相比,添加陶瓷相的样品的抗压强度由1380.15 MPa提高至1974.17 MPa,屈服强度提高至1664.13 MPa,硬度提高3~5倍。保温时间越长,材料的抗压强度、屈服强度和硬度越高。复合材料强度和硬度提高是固溶强化以及ZrB和NbMo之间良好的界面结合力的结果。
Two kinds of ZrB 2 reinforced NbMo matrix composites were prepared by vacuum hot-pressing sintering: 42.5% Nb + 42.5% Mo + 15% ZrB 2, 42.5% Nb + 42.5% Mo + 10.5% ZrB 2+ 4.5% Volume fraction). Sintering process temperature 1600 ℃, axial stress 30 MPa, the protective gas is argon, holding time is divided into 1 h and 2 h. The microstructure and phase composition of the material were analyzed by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry. The mechanical properties of the material were measured using a micro Vickers hardness tester and a hydraulic universal testing machine. It is found that the ZrB particles are uniformly distributed in the NbMo solid solution, with the addition of SiC and the formation of the MoSi 2 phase in the SiC-added sample. The compressive strength of the sample added with ceramic phase increased from 1380.15 MPa to 1974.17 MPa, the yield strength increased to 1664.13 MPa and the hardness increased by 3 ~ 5 times compared with the sample without ceramic phase. The longer the holding time, the higher the compressive strength, yield strength and hardness of the material. The strength and hardness increase of the composite material are the result of solid solution strengthening and good interfacial adhesion between ZrB and NbMo.