添加氧化镧WC-11Co-2.1TaC硬质合金的组织及性能

Microstructure and properties of WC-11Co-2.1TaC cemented carbides by adding La_2O_3

硬质合金的晶粒度和组织均匀性是制约其性能的关键因素。为了细化晶粒,改善组织,提高合金性能,采用粉末碳化、冷压烧结技术,以W、Co、Ta为原料,La2O3为添加剂,制备WC-11Co-2.1Ta C硬质合金,研究添加La2O3对硬质合金组织和力学性能的影响。结果表明：添加0.2%～0.4%La2O3可抑制WC-11Co-2.1Ta C硬质合金组织WC晶粒聚集生长,使组织均匀,WC相邻接度减小,WC/Co接触面积增大,提高抗弯强度;当La2O3添加量增加到0.6%时,合金组织偏聚,WC晶粒严重聚集生长,WC相邻接度增大,提高了硬质合金抵抗显微金刚石压头的刻入能力,增大了显微硬度。

Grain size and even structuring of the hard alloy are the two key elements in its performance.In order to refine the grain and the strucure and improve the performance of the alloy,the WC-11Co-2. 1Ta C cemented carbides are prepared by powder carbonization and cold compaction sintering process. The W and Co and Ta powder are used as raw materials and La2O3 as additive. Its aim is to analysis the effect of La2O3 on microstructure and properties of WC-11Co-2. 1Ta C cemented carbides. The result shows that,the clustered growth of WC grain is restrained by La2O3 with mass percent of 0. 2% - 0. 4%,which makes microstructure uniform and contiguity of WC phase decreased,therefore,contact area of WC / Co increase and enhance the bending strength. The microstructure segregation of cemented carbides occur,which can result in the clustered growth of WC grain and contiguity of WC phase increased and lead to the improvement of microhardness.