(湘潭大学 机械工程学院,湘潭 411105)
摘 要: 为了改善17Ni-(10NiO-NiFe2O4)金属陶瓷惰性阳极中金属相的分布,在原料中添加不同含量的Co,以Co-Ni取代纯Ni作为金属相,采用真空烧结方法制备17(xCo-Ni)-(10NiO-NiFe2O4)金属陶瓷,并研究Co添加量对金属陶瓷物相组成、显微组织、致密度及力学性能的影响。结果表明:烧结样品主要由Co-Ni、NiFe2O4、NiO组成,部分Co与陶瓷基体反应生成CoO与Fe2O3。添加适量Co可以改善金属相在陶瓷相的分布和形貌,使团聚孤立的金属相分布均匀,且部分球状金属相变为长条状金属相;同时,添加适量Co还可以促进烧结,提高试样的致密度。适量Co的添加还能降低晶粒尺寸,大幅提高金属陶瓷材料强度与韧性。当Co质量分数为金属相的20%时,金属陶瓷的综合性能最好,致密度、抗弯强度、断裂韧性及硬度分别达到96.87%、163.65 MPa、8.38 MPa/m1/2和820.81HV。
关键字: 10NiO-NiFe2O4基金属陶瓷;Co添加;致密度;力学性能
(School of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China)
Abstract:In order to improve the distribution of metal phase in the 17Ni-(10NiO-NiFe2O4) cermet, 17(xCo-Ni)-(10NiO-NiFe2O4) cermet were prepared by vacuum sintering method using Co-Ni instead of Ni as the metal phase. And the effects of Co content on the phase composition, microstructure, relative density and mechanical properties of the cermet were investigated. The results show that the cermet is composed of Co-Ni, NiFe2O4 and NiO, a part of Co reacts with ceramic matrix to form CoO and Fe2O3. The proper addition of Co can significantly improve the distribution and morphology of the metal phase, the agglomerate isolated metal phases can distribute uniformly and a part of spherical metal phases can change to elongated metal phases. Moreover, the proper addition of Co can promote sintering and increase the density of sample. Co addition can refine the grain size and greatly increase the strength and the toughness of cermet. When the mass fraction of Co in metal phase is 20%, the combination properties of sample are the best. The density, bending strength, fracture toughness and hardness are 96.87%, 163.65 MPa, 8.38 MPa/m1/2 and 820.81 HV, respectively.
Key words: 10NiO-NiFe2O4 based cermet; Co addition; relative density; mechanical property