稀土添加量对TiC基钢结硬质合金性能的影响

Effect of rare earth addition on properties of TiC-based steel bonded carbide

采用真空烧结法以TiC粉、纯Mo粉、纯Cr粉、羰基Fe粉、鳞片状石墨等为原料,制备了TiC基钢结硬质合金,并采用含Ce的环烷酸稀土作为成形剂,通过加入不同含量的Ce元素对其进行改性。利用SEM、万能实验机、洛氏硬度计等对烧结试样进行显微组织和性能分析。结果表明,添加稀土元素进行改性后的合金试样接近全致密;同时,TiC更加均匀地分布于基体中;添加Ce元素质量分数为0.2%时,合金抗弯强度达到最大值,相比不含Ce的合金试样提高近28%。

The TiC-based steel bonded carbide was prepared by vacuum sintering using titanium carbide,molybdenum,chromium,carbonyl iron powder and flaky graphite as raw material.The alloy was modified by adding forming agent naphthenates containing rare earth Ce.Scanning electron microscopy （SEM） was used for characterization.Moreover,the transverse rupture strength （TRS） and hardness were also measured,and attempts were made to relate them to the microstructure development.The results indicate that the addition of rare earth greatly increases the density.TiC particles are distributed in the matrix more uniformly as well.The sample with 0.2％ Ce （mass percent） has the maximum transverse rupture strength,which is increased by 28％ compared to samples without Ce.