摘要
超细WC粉末是制备超细硬质合金的主要原材料,本文采用XRD﹑SEM﹑TEM等分析手段,研究了三种不同粒度的超细WC粉末中微观缺陷的种类及其在晶粒中的分布,探讨了超细WC粉末微观缺陷的形成原因。分析结果表明:超细WC粉末主要为多晶颗粒,其位错密度较大,高于常态下一般的金属或合金。其微观缺陷的存在形式主要有位错﹑层错﹑孪晶等。在钨转化为碳化钨的相变过程中,钨原子密度由6.309 446个/nm3降低为3.211 922个/nm3,体积膨胀31%,为了释放其中的应力,必须存在有数量较多的缺陷。
Uhrafine tungsten carbide powder is one of the main raw materials for ultrafine grained cemented carbide. The types of micro defects in three grades of ultrafine tungsten carbide powder with different particle sizes and their distribution in the grains were Studied via XRD, SEM, TEM, in addition the formation reasons of the micro defects were discussed. The results show that, the ultrafine tungsten carbide powder includes many multigrains. The dislocation density of ultrafine tungsten carbide powder is higher than that of the general metals or alloys in normal state, the types of micro defects are dislocation, stacking fault and twin crystal and so on. The analysis show that during the process of tungsten phase transforming into tungsten carbide phase, the density of tungsten atom decreases from 6.309 446 per cubic nanometer to 3.211 922, the volume of tungsten expands of 31%. A considerable number of micro defects exist mainly due to the release of the stress.
出处
《硬质合金》
CAS
2012年第5期283-288,共6页
Cemented Carbides
关键词
WC
超细粉末
微观缺陷
位错
硬质合金
WC
ultrafine powder
, micro defects
dislocation
cemented carbide
