【摘要】 采用真空液相烧结法制备了Mo₂FeB₂基金属陶瓷，研究了CeO₂含量对其组织和力学性能的影响。结果表明：CeO₂的添加使金属陶瓷出现B₂O₃相，Ce主要固溶于Mo₂FeB₂硬质相中。随着CeO₂含量增加，金属陶瓷中气孔率增大，柱状晶减少，等轴晶数量增加，等轴晶晶粒尺寸增加，金属陶瓷中的晶粒尺寸趋于均匀化。随着CeO₂添加量的增加，金属陶瓷的抗弯强度持续下降；硬度整体呈下降趋势，但当CeO₂质量分数为0.50%和1.00%时硬度均有上升；断裂韧性均表现为先增大后减小，当CeO₂质量分数为0.75%时，金属陶瓷的断裂韧性达到最大值34.5 MPa·m^1/2，相比基体成分金属陶瓷断裂韧性增长68%。当CeO₂质量分数为0.50%时，金属陶瓷表现出较好的综合力学性能，抗弯强度为1 775 MPa，硬度为HRA 88.5，断裂韧性为30.2 MPa·m^1/2。更多还原

【Abstract】 Mo₂FeB₂-based cermets were prepared by the vacuum liquid phase sintering method,and the effect of the CeO₂content on the structure and mechanical properties of Mo₂FeB₂-based cermets was studied.The results show that the addition of CeO₂makes the cermets form a B₂O₃phase,and Ce is mainly dissolved in the hard phase of Mo₂FeB₂.With the increase in the CeO₂content,the porosity of cermets,the number of equiaxed crystals,and the grain size rise while the columnar crystals decrease,and the grain size in the cermets tends to be uniform;With the increasing addition of CeO₂,the bending strength of cermets declines continuously,and the overall hardness shows a downward trend.However,when the CeO₂mass fraction is 0.50%and 1.00%,the hardness grows,and the fracture toughness increases before it decreases;when the CeO₂mass fraction is 0.75%,the maximum fracture toughness of the cermet is 34.5 MPa·m^1/2,which is 68%higher than that of matrix cermets.When the CeO₂mass fraction is 0.50%,the cermets show better comprehensive mechanical properties,with bending strength of 1 775 MPa,hardness of 88.5 HRA,and fracture toughness of 30.2 MPa·m^1/2.更多还原