In the binder jetting (BJ) additive manufacturing of cemented carbides, the abnormal growth of WC grains and the formation of coarse WC grain clusters pose significant challenges. This study introduces a novel approach to address these issues by incorporating micron-sized Cr3C2, a recognized inhibitor of WC grain growth, into spherical WC-17Co granules at varying concentrations for the BJ process. This method targets the inherent microstructural inhomogeneity of BJ-processed carbides. We systematically examined the impact of Cr3C2 content on the microstructure and mechanical properties of BJ-processed WC-17Co carbides. Our findings show that Cr3C2 effectively inhibits abnormal WC grain growth, enhancing the microstructural homogeneity of BJ-processed carbides. The average WC grain size was reduced from 1.57 μm in the plain WC-17Co to 1.39 and 1.35 μm with the addition of 0.5 wt% and 1 wt% Cr3C2, respectively. Concurrently, the hardness increased substantially to 1248 HV30 and 1232 HV30 with the same Cr3C2 additions, compared to 1149 HV30 for the plain WC-17Co. However, the addition of 0.5 wt% and 1 wt% Cr3C2 also led to a decrease in fracture toughness to 14.5 and 14.2 MPa·m1/2, respectively, from 17.5 MPa·m1/2 for the plain WC-17Co. Similarly, the transverse rupture strength decreased to 2151 MPa and 1993 MPa, respectively, from 2211 MPa for the plain carbide. Despite these reductions, the wear resistance was improved by 49.6 % and 15.4 % with the addition of 0.5 wt% and 1 wt% Cr3C2, respectively. Additionally, Cr3C2 enhanced the surface quality of BJ-processed WC-17Co carbides. The optimal microstructure homogeneity, high relative density, and favorable mechanical behavior were achieved with a 0.5 wt% Cr3C2 addition. These findings highlight the potential of Cr3C2 as a microstructural modifier in the binder jetting additive manufacturing of cemented carbides, suggesting a promising strategy to tailor the material properties for specific applications.

中文翻译：

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Cr3C2 添加剂对粘结剂喷射添加剂制备的硬质合金微观组织和力学行为的影响


在硬质合金的粘结剂喷射 （BJ） 增材制造中，WC 晶粒的异常生长和粗 WC 晶粒簇的形成构成了重大挑战。本研究介绍了一种解决这些问题的新方法，方法是将微米级的 Cr3C2（一种公认的 WC 颗粒生长抑制剂）掺入不同浓度的球形 WC-17Co 颗粒中，用于 BJ 工艺。该方法针对 BJ 加工碳化物固有的微观结构不均匀性。我们系统地研究了 Cr3C2 含量对 BJ 加工的 WC-17Co 碳化物的微观结构和力学性能的影响。我们的研究结果表明，Cr3C2 有效抑制了异常的 WC 晶粒生长，增强了 BJ 加工碳化物的微观结构均匀性。平均 WC 晶粒尺寸从普通 WC-17Co 的 1.57 μm 减小到 1.39 和 1.35 μm，分别添加了 0.5 wt% 和 1 wt% 的 Cr3C2。同时，在添加相同 Cr3C2 的情况下，硬度大幅提高到 1248 HV30 和 1232 HV30，而普通 WC-17Co 的硬度为 1149 HV30。然而，添加 0.5 wt% 和 1 wt% Cr3C2 也导致普通 WC-17Co 的断裂韧性从 17.5 MPa·m1/2 分别降低到 14.5 MPa·m1/2 和 14.2 MPa·m1/2。同样，普通硬质合金的横向断裂强度分别从 2211 MPa 降至 2151 MPa 和 1993 MPa。尽管降低了这些，但添加 0.5 wt% 和 1 wt% Cr3C2 后，耐磨性分别提高了 49.6% 和 15.4%。此外，Cr3C2 提高了 BJ 加工的 WC-17Co 碳化物的表面质量。添加 0.5 wt% Cr3C2 实现了最佳的微观结构均匀性、高相对密度和良好的机械行为。 这些发现突出了 Cr3C2 在硬质合金的粘结剂喷射增材制造中作为微观结构改性剂的潜力，提出了一种为特定应用定制材料性能的有前途的策略。