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采用单质硼粉、镍粉和钼粉结合反应硼化烧结法制备了Mo2Ni B2基金属陶瓷,研究了Mo2Ni B2基金属陶瓷在烧结过程中的物相转变和尺寸变化以及烧结温度和保温时间对其力学性能和显微组织的影响.结果发现:随着烧结温度升高,材料物相逐渐由单质相变为二元硼化物相和三元硼化物相,并且材料的尺寸先发生细微收缩,再在硼化反应过程中逐渐增加,最后在液相烧结过程中逐渐减小;随着烧结温度升高,Mo2Ni B2基金属陶瓷的抗弯强度和硬度先增加后减小,在1290℃达到最大,分别为1346.5 MPa和83.7 HRA,并且硬质相颗粒逐渐粗化;保温时间对材料性能的影响与烧结温度一致,但在保温30min时抗弯强度最大(1453.3 MPa),保温60 min时硬度最大(83.7 HRA).
The Mo2Ni B2-based cermets were prepared by borosilicate sintering with the combination of simple boron powder, nickel powder and molybdenum powder. The phase transformation and size change of Mo2Ni B2-based cermets during sintering were investigated. The effects of sintering temperature and holding time on the Mo2Ni B2- Mechanical properties and microstructures.It is found that with the increase of sintering temperature, the phase of the material gradually changes from simple substance to binary boride phase and ternary boride phase, and the size of the material firstly shrinks slightly, then And gradually decreased during the boride reaction. Finally, the sintering temperature of Mo2Ni B2-based cermets increased first and then decreased with the increase of sintering temperature, reaching the maximum at 1290 ℃, (1346.5 MPa and 83.7 HRA respectively), and the hard phase particles gradually roughened. The effect of holding time on the properties was consistent with the sintering temperature, but the bending strength was the highest (1453.3 MPa) at 30 min and the hardness was the highest at 60 min 83.7 HRA).