【摘要】 用透射电子显微镜对YG8、YG11、YG12和H₁₂S₂等几种硬质合金中WC的微观结构和形变断裂过程进行了观察、电子衍射和衍衬分析。结果表明,合金中WC晶粒内部有着非常丰富的微观结构,例如,高密度的位错纠缠、堆垛层错、界面位错、超位错、小角度晶界,以及由位错交互作用形成的位错网络等。本文着重探讨了,当合金承受应力,产生应变和断裂时,WC晶内微观结构变化规律,这为合金穿晶断裂提供了实验依据,并试图从晶体学的角度给予解释。更多还原

【Abstract】 The observation,electron diffraction and diffraction contrast on the microstructure and defo-rmation fracture process of WC in cemented carbides,such as YG8,YG11,YG12 and H₁₂S₂,werecarried out with TEM. It is indicated that there are varieties of microstructure in WC grains,suchas dislocation tangling with high density,stacking faults,interface dislocation,superdislocations,small-angle grain boundry and dislocation networks formed by the interaction of dislocations. Thispaper mainly deals with the behavior of the microstructure change in WC in the case of that thealloys are subjected to a stress,and the strain and fracture occurs. The evidence of transgranularfracture for the alloys is provided and the explanation would be made from the point of view ofcrystallography.更多还原