CAJ | 학술논문

采用单质硼粉、镍粉和钼粉结合反应硼化烧结法制备了Mo2 NiB2基金属陶瓷,研究了Mo2 NiB2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,Mo2 NiB2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30 min时抗弯强度最大(1453.3 MPa),保温60 min时硬度最大(83.7 HRA).
채용단질붕분、얼분화목분결합반응붕화소결법제비료Mo2 NiB2기금속도자,연구료Mo2 NiB2기금속도자재소결과정중적물상전변화척촌변화이급소결온도화보온시간대기역학성능화현미조직적영향.결과발현：수착소결온도승고,재료물상축점유단질상변위이원붕화물상화삼원붕화물상,병차재료적척촌선발생세미수축,재재붕화반응과정중축점증가,최후재액상소결과정중축점감소；수착소결온도승고,Mo2 NiB2기금속도자적항만강도화경도선증가후감소,재1290℃체도최대,분별위1346.5 MPa화83.7 HRA,병차경질상과립축점조화；보온시간대재료성능적영향여소결온도일치,단재보온30 min시항만강도최대(1453.3 MPa),보온60 min시경도최대(83.7 HRA).
Mo2 NiB2 based cermets were prepared using element powders of boride, nickel and molybdenum. The phase transfor-mation and dimensional change in the sintering stage as well as the effects of sintering temperature and holding time on the mechanical properties and microstructure of Mo2 NiB2 based cermets were studied. The results show that with the increasing of sintering tempera-ture, the phase gradually transfers from elemental phase to diboride and then to ternary boride phase, the dimension of the cermets also firstly slightly decreases, then obviously increases in the boronizing sintering process, and finally significantly reduces in the subse-quent liquid sintering process. The bending strength and hardness of the cermets firstly increase and then decrease when the sintering temperature rises. The cermets sintered 1290℃ for 60 min show the best mechanical properties with the bending strength of 1346. 5 MPa and the hardness of 83. 7 HRA. Holding time has a similar effect on the mechanical properties of the cermets. When the holding time is 30 min at 1290℃, the bending strength reaches the maximum of 1453. 3 MPa.