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本文运用XRD和SEM等对比研究了烧结气氛对Mo2FeB2基金属陶瓷相组成、显微组织和力学性能的影响。结果表明,当烧结温度为1250℃,保温时间为40min时,真空烧结后,金属陶瓷可获得较均匀的显微组织和较佳的力学性能,抗弯强度为1774MPa,硬度为90.4HRA;氩气气氛烧结时,由于碳不能完全除去粉末颗粒表面和B2O3中的氧,降低了烧结过程中液相对硬质相颗粒的润湿性,从而导致金属陶瓷的力学性能明显降低;氮气气氛烧结时,粘结相Fe与氮气发生反应生成了Fe3N,导致烧结过程中没有出现液相,未能得到致密的烧结体。
In this paper, the effects of sintering atmosphere on the phase composition, microstructure and mechanical properties of Mo2FeB2-based cermets were investigated by XRD and SEM. The results show that when the sintering temperature is 1250 ℃ and the holding time is 40min, the microstructure and mechanical properties of cermets obtained after vacuum sintering are better. The flexural strength is 1774MPa and the hardness is 90.4HRA. Atmosphere sintering, due to the carbon can not completely remove the oxygen in the surface of the powder particles and B2O3, reducing the wetting of the liquid phase of the hard phase particles during sintering, resulting in significantly reduced mechanical properties of the cermet; nitrogen atmosphere sintering, the viscosity Nodular Fe reacts with nitrogen to form Fe3N, resulting in no liquid phase during sintering and no compact sintered body.