球磨时间对Mo_2FeB_2基金属陶瓷组织和力学性能的影响

以Mo、FeB、Cr、Ni、Fe粉末以及少量的C粉为原料,采用行星球磨法对其球磨后烧结制备Mo2FeB2基金属陶瓷,利用扫描电镜观察球磨粉及其烧结试样的组织形貌,并测定烧结试样的孔隙度、硬度和抗弯强度,研究原料粉末球磨时间对Mo2FeB2基金属陶瓷组织和力学性能的影响。结果表明,随着球磨时间的增加,粉末粒度逐渐变小,Mo2FeB2基金属陶瓷的孔隙度明显降低,其硬度和抗弯强度明显增大,晶粒也随之细化;球磨30h原料粉末所制Mo2FeB2基金属陶瓷的综合性能最优,其硬度(HRA)达到90.2,抗弯强度达到1850MPa。

Effect of ball milling time on the microstructure and mechanical properties of Mo2FeB2-based cermet

With Mo, FeB, Cr, Ni, Fe powder and a small amount of C powder as the raw materials, the Mo₂FeB₂-based cermet was prepared by sintering treatment after being ball-milled by planetary ball milling method. The microstructure and morphologies of the raw material powder and sintered sample were observed by scanning electron microscope. The porosity, hardness and bending strength of sintered samples were measured. The effect of ball-milling time of raw material powder on the microstructure and mechanical properties of Mo₂FeB₂-based cermet were studied. The results show that with ball-milling time increasing, particle size of mixed powder gradually decreases, porosity of Mo₂FeB₂-based cermet obviously decreases, hardness and bending strength of Mo₂FeB₂-based cermet significantly increase,and grain crystal of the cermet is refined. Under the ball-milling time of 30 h, the performance of Mo₂FeB₂-based cermet reaches an optimal value, when hardness and bending strength reach 90.2 and 1850 MPa,respectively.