采用粉末冶金工艺制备硬质合金时，坯体的成形工艺对烧结制备硬质合金的组织和力学性能有显著影响，但目前缺乏规律性的认识。本工作以原位合成的超细WC-Co复合粉末为原料，研究了在粉末压制成坯体过程中成形剂的含量和溶液浓度以及生坯密度等成形工艺参数对烧结制备WC-12Co硬质合金尺寸、微观组织和力学性能的影响规律。结果表明，成形剂聚乙二醇(PEG)含量在一定范围内增加会导致烧结硬质合金中磁性Co含量呈线性增长，而PEG溶液的浓度主要影响其在粉末中分散的均匀性与喂料粒度，2者均会显著影响烧结制备硬质合金的物相、致密性和力学性能。压制过程中随生坯密度在一定范围内增加，烧结制备硬质合金的收缩率与其保持良好的线性关系，致密性先显著增加后保持稳定，抗弯强度则呈先增大后减小的变化趋势。当PEG质量分数为1.5%、PEG浓度为4.1%和生坯密度为7.7 g/cm³时，烧结制备硬质合金抗弯强度平均值达到4571 MPa，且测量值波动小。WC晶内形成的大量富Co纳米相阻碍位错运动是硬质合金强度提升的主要原因。

The quality of the green body is crucial for achieving excellent mechanical properties in sintered cemented carbides via the powder metallurgy process, making it necessary to explore and optimize the powder molding process. In this study, the effects of the content and solution concentration of the pressing binder, as well as the green density during the powder molding process, on the geometries, microstructures, and mechanical properties of sintered WC-12Co cemented carbides were investigated. These materials were produced using in situ synthesized ultrafine WC-Co composite powder as the raw material. The results indicated that increasing the polyethylene glycol (PEG) content as the pressing binder within a certain range led to a linear increase in the magnetic Co content of the sintered cemented carbides. The concentration of the PEG solution primarily influenced its dispersion in the powder and feedstock particle size. Both of which considerably influenced the phase constitution, density, and mechanical properties of the prepared cemented carbides. During the pressing process, as the green density increased within a certain range, the shrinkage rate of the sintered alloys exhibited a good linear relationship with it. Additionally, the density of the cemented carbides initially increased notably and then stabilized, whereas the fracture strength initially increased and then decreased. By optimizing the conditions to 1.5% PEG content, 4.1% PEG concentration, and a green density of 7.7 g/cm³, the sintered cemented carbide achieved an exceptional average transverse rupture strength of 4571 MPa with minimal fluctuations in the measured values. The formation of numerous Co-rich nanophases within the WC grains, which hinder dislocation movement, is the primary reason for the enhanced strength of the cemented carbide.