纳米La2O3掺杂对Mo2NiB2基金属陶瓷组织及力学性能的影响

Effect of Nano-La2O3 Doping on Microstructure and Mechanical Properties of Mo2NiB2 Based Cermets

采用真空热压烧结技术,根据Ni-6B-53.3Mo的配比,制备了掺杂不同含量纳米La2O3颗粒(0、0.3%、0.6%、0.9%、1.2%)的Mo2NiB2基金属陶瓷,并研究其显微结构和力学性能。结果表明,掺杂La2O3可以使Mo2NiB2基金属陶瓷的硬质相和Ni基粘结相相溶性提高,晶粒尺寸减小,Ni基粘结相分布更加均匀。随着La2O3掺杂含量的增加,Mo2NiB2基金属陶瓷的抗弯强度、硬度和压缩强度先增大后减小。掺杂0.6%La2O3时,抗弯强度和硬度均最大,分别为603.55 MPa和902.1 HV。掺杂0.3%La2O3时,压缩强度最大,为550 MPa。但随着La2O3掺杂含量的增加,Mo2NiB2基金属陶瓷的断裂韧性和密度都有所降低。

Based on the composition of Ni-6 B-53.3 Mo,Mo2NiB2 based cermets with different content of nano-La2O3 particles(0,0.3%,0.6%,0.9%,1.2%)were prepared by vacuum hot pressing sintering technology,and their microstructure and mechanical properties were studied.The results show that doping La2O3 can improve the solubility of hard phase and Ni based binding phase of Mo2NiB2 based cermets,reduce the grain size and make the distribution of Ni based binding phase more uniform.With the increase of La2O3 content,the bending strength,hardness and compressive strength of Mo2NiB2 based cermets increase first and then decrease.The cermet with 0.6%La2O3 has the maximum bending strength and hardness of 603.55 MPa and 902.1 HV,respectively.The cermet with 0.3%La2O3 has the maximum compressive strength of 550 MPa.However,with the increase of La2O3 content,both the fracture toughness and density of Mo2NiB2 based cermets decrease.