The deformation and fracture behaviour of constituents of a WC-Co hardmetal were investigated by microcantilever bending technique. The compositions of FIB fabricated microcantilevers were: I) single grains of WC, II) WC grains of different orientations and III) the mixture of WC grains and Co phase. The crystallographic orientation of WC grains and the fracture surface of beams were studied by EBSD and SEM analyses, respectively. It was revealed that the elastic deformation depends mainly on the composition of the beams and the orientation of the WC grains. The Young's modulus of WC grains showed an orientation dependence with decreasing values from the basal (E~800 GPa) towards the prismatic orientations (E~500 GPa), which is in agreement with the theoretical predictions. The deformation behaviour of WC grains exhibited plasticity before their fracture with an average fracture strength of σ = 12.3 ± 3.8 GPa. It was found that the effect of dislocations and nanometre-sized defects (e.g. pores) plays an important role in the bending test of WC grains. Most of the WC/WC boundaries showed brittle failure with an average fracture strength of σ = 4.1 ± 2.5 GPa. It was concluded that the majority of the boundaries in the WC-Co composite are high energy WC/WC boundaries and their fracture strength is generally much lower than that of the WC grains.

通过微悬臂梁弯曲技术研究了WC-Co硬质合金成分的变形和断裂行为。FIB制成的微悬臂梁的组成为：I）WC的单个晶粒，II）不同取向的WC晶粒，以及III）WC晶粒与Co相的混合物。通过EBSD和SEM分析分别研究了WC晶粒的结晶取向和梁的断裂面。结果表明，弹性变形主要取决于梁的组成和WC晶粒的取向。WC晶粒的杨氏模量显示出与从基部（减小值的方位依存性ë〜800 GPa）的朝向所述棱柱取向（Ë〜500 GPa），与理论预测相符。WC晶粒的变形行为在断裂前表现出可塑性，平均断裂强度为σ  = 12.3±3.8 GPa。已经发现，位错和纳米级缺陷（例如孔）的影响在WC晶粒的弯曲试验中起着重要的作用。大部分WC / WC边界显示脆性破坏，平均断裂强度为σ  = 4.1±2.5 GPa。结论是，WC-Co复合材料中的大多数边界都是高能WC / WC边界，并且其断裂强度通常远低于WC晶粒的断裂强度。