Mo_2FeB_2基新型硬质合金的制备

PREPARATION OF Mo_2FeB_2 BASED NEW HARD ALLOYS

本文采用真空反应烧结法原位合成制备了Mo2FeB2基新型硬质合金,研究了Mo2FeB2基新型硬质合金及烧结温度和保温时间对合金组织和性能的影响。利用扫描电镜(SEM)和X射线衍射仪(XRD)对试样的组织和物相进行了分析,测定了试样的密度、抗弯强度(TRS)和硬度(HRA)。实验结果表明,提高烧结温度或延长保温时间都会导致合金中的Mo2FeB2颗粒形貌从近球形向长条形转变,导致抗弯强度降低。本实验烧结温度为1 270℃,保温0min时获得的硬质合金的组织和性能最佳,其抗弯强度为1 780MPa,硬度为86HRA。

The Mo2FeB2 based hard alloy was prepared by vacuum reaction sintering. The effects of final sintering temperature and holding time on microstructure and mechanical property were investigated. Scanning electron microscopy （SEM） and X-ray diffraction （XRD） were used for characterization. Moreover, the transverse rupture strength （TRS） and hardness （HRA） were also measured, and attempts were made to relate them to the mi- crostructure development. The results indicate that increasing the final sintering temperature or prolonging the holding time lead to the change of Mo2 FeB2 grains shape from spherical to cubic which decrease the transverse rupture strength The best mechanical properties of Mo2FeB2 based hard alloy are obtained when the final sintering temperature is 1270℃ and holding time 0min i. e. transverse rupture strength of 1780Mpa, and hardness of 86HRA.