稀土Sm_2O_3对Mo_2NiB_2基金属陶瓷微观组织和力学性能的影响

Effect of rare earth Sm_2O_3 on microstructure and mechanical properties of Mo_2NiB_2 based cermets

以NiB、Mo、Cr、V、Ni等几种粉末为基本原料,并以稀土Sm_2O_3为添加剂,采用真空液相烧结法制备Mo_2NiB_2基金属陶瓷。利用XRD、SEM、EDS、洛氏硬度计和电子万能试验机等研究添加Sm_2O_3对Mo_2NiB_2基金属陶瓷微观组织和力学性能的影响。结果表明,添加0.3%~0.9%的Sm_2O_3后,金属陶瓷晶粒明显细化,组织分布更加均匀,材料的硬度和抗弯强度也得到提高。当Sm_2O_3添加量为0.6%时,所得试样的晶粒最为细小,晶粒尺寸大致在0.8~3.0μm,材料的力学性能最佳,其硬度和抗弯强度分别达到HRA88.7和1550 MPa。

With NiB, Mo, Cr,V and Ni powders as basic raw materials,rare earth Sm2O3 as additive,Mo2NiB2 based cermets were prepared by vacuum liquid-phase sintering technology. Effects of Sm2O3 on the microstructure and mechanical properties of MO2NiB2 based cermets were investigated bymeans of XRD,SEM,EDS,Rockwell hardness tester and electronic universal testing machine. The results show that,when the added amount of Sm2O3 is 0.3 %-0.9%,the cermets have finer grainsand more homogeneous microstructure, and their hardness and bending strength also increase. The samplewith 0. 6% Sm2O3 has the smallest grain size （0.8-3.0 μm） and the bestmechanical proper-ties. Its hardness and bending strength reach HRA88.7 and 1 550 MPa,respectively.