To scientific understanding the effect of a slight change in carbon content near the upper/lower limit on alloys, five sets of WC-10Co cemented carbides were prepared with the carbon content of 5.34 wt%, 5.36 wt%, 5.44 wt%, 5.53 wt% and 5.56 wt% respectively. The properties of the alloys are analyzed by SEM, XRD, Hardness tester, universal testing machines, HSR-2 M tribometer, and surface characterisation. The results showed that the existent of multi-steps proved that the WC coarsening process was governed by 2-D nucleation in the alloy with low carbon content. On the contrary, the low W solubility in Co and the low melting point of Co binder accelerated the dissolution-precipitation process with increasing carbon content. At this time, the morphologies of WC grains tented to be the triangular shape without multi-steps due to the continuous grain growth. Additionally, the increasing of the value of carbon content brought about the coarser WC grain size, and the particle size distribution with “double peak” was also observed in the alloy with free carbon. Further analysis of XRD, the various dissolution of W in Co binder phase brought about a minor different intensity of the basal plane (0001) peaks. Moreover, a slight change in carbon content near the upper/lower limit also significantly affected the mechanical properties of alloys. The cemented carbides with 5.44 wt% carbon content in two phase range exhibited a combination of superior mechanical properties and wear resistance.

为了科学理解碳含量略有上下变化对合金的影响，制备了五套WC-10Co硬质合金，碳含量分别为5.34 wt％，5.36 wt％，5.44 wt％，5.53 wt ％和5.56wt％。通过SEM，XRD，硬度测试仪，通用测试仪，HSR-2 M摩擦计和表面特性分析了合金的性能。结果表明，多步骤的存在证明了低碳含量合金中WC的粗化过程是由二维成核作用决定的。相反，Co中低的W溶解度和Co粘合剂的低熔点随着碳含量的增加而加速了溶解沉淀过程。此时，由于晶粒的连续生长，WC晶粒的形态趋于三角形，没有多步。另外，碳含量值的增加导致WC晶粒尺寸更大，并且在具有游离碳的合金中还观察到具有“双峰”的粒径分布。XRD的进一步分析表明，W在Co粘结相中的各种溶解导致基面（0001）峰的强度略有不同。而且，碳含量在上限/下限附近的微小变化也显着影响了合金的机械性能。在两相范围内碳含量为5.44 wt％的硬质合金表现出优异的机械性能和耐磨性的组合。碳含量值的增加导致WC晶粒尺寸更大，并且在含游离碳的合金中还观察到具有“双峰”的粒径分布。XRD的进一步分析表明，W在Co粘结相中的各种溶解导致基面（0001）峰的强度略有不同。而且，碳含量在上限/下限附近的微小变化也显着影响了合金的机械性能。在两相范围内碳含量为5.44 wt％的硬质合金表现出优异的机械性能和耐磨性的组合。碳含量值的增加导致WC晶粒尺寸更大，并且在含游离碳的合金中还观察到具有“双峰”的粒径分布。XRD的进一步分析表明，W在Co粘结相中的各种溶解导致基面（0001）峰的强度略有不同。而且，碳含量在上限/下限附近的微小变化也显着影响了合金的机械性能。在两相范围内碳含量为5.44 wt％的硬质合金表现出优异的机械性能和耐磨性的组合。W在Co粘结相中的各种溶解导致基面（0001）峰的强度略有不同。而且，碳含量在上限/下限附近的微小变化也显着影响了合金的机械性能。在两相范围内碳含量为5.44 wt％的硬质合金表现出优异的机械性能和耐磨性的组合。W在Co粘结相中的各种溶解导致基面（0001）峰的强度略有不同。而且，碳含量在上限/下限附近的微小变化也显着影响了合金的机械性能。在两相范围内碳含量为5.44 wt％的硬质合金表现出优异的机械性能和耐磨性的组合。