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采用粉末冶金工艺制备了不同Mo含量Ni_3Al粘结金属陶瓷,采用XRD,TEM和EDS等表征技术分析了其组织及成分.结果表明:金属陶瓷组织表现为芯/环结构硬质相颗粒分布在粘结相中,硬质相基本为黑芯-白环结构,而当Mo含量(质量分数)达到15%时,出现灰白色外环-亮白色内环-黑芯结构的硬质相颗粒;同时,随Mo含量的增加,硬质相颗粒明显细化;液相烧结过程中Mo趋向于在碳化物表面聚集析出,形成富Mo内环相.Ni_3Al粘结金属陶瓷力学性能分析表明:抗弯强度和硬度随Mo含量增加先增大后减小,在添加8%质量分数的Mo时达到最大值,分别为1 396 MPa和HRA91.0.
The microstructure and composition of Ni_3Al bonded cermets with different Mo content were prepared by powder metallurgy process.The microstructures and compositions of Ni_3Al bonded cermets were characterized by XRD, TEM and EDS.The results showed that the microstructure of the cermet was characterized by the distribution of hard phase particles in the core / In the jelly phase, the hard phase is basically a black core - white ring structure, and when the Mo content (mass fraction) reaches 15%, the hard white phase particles with an outer white outer ring - the bright white inner ring and the black core structure appear; With the increase of Mo content, the hard phase particles are obviously refined. Mo tends to accumulate and precipitate on the carbide surface during the liquid phase sintering process, forming the Mo-rich inner ring phase.The mechanical properties of Ni3Al-bonded cermets show that the flexural strength and The hardness first increases and then decreases with the increase of Mo content, and reaches the maximum values of 1 396 MPa and HRA91.0 when adding 8% Mo.