This work investigates the critical roles of two-step sintering (TSS) and laminated structure on the sintering behavior and mechanical properties of functionally graded WC-TiC-Al₂O₃ nanostructured composite materials doped with Cr₃C₂/VC. Results show that excellent mechanical properties are achieved for tailored TSS conditions with a hardness of 27.91 ± 2.3 GPa and a flexural strength of 1423.3 ± 23.5 MPa. The desirable mechanical properties are attributed to the suppressed grain growth without densification deterioration. TSS is more effective in facilitating the favorable dispersion of secondary phase toughening nano-particulates in a WC matrix than conventional sintering (CS). Cr₃C₂/VC dopant plays an important role in maximizing and shifting the temperature range of the kinetic window for WC-Al₂O₃ composites. Al₂O₃ crack deflection, transgranular Al₂O₃, microcracking, WC crack bridging and plate-like WC crack deflection are the major toughening mechanisms. Residual surface compressive stress induced by the graded structure is also an appreciated contribution to the improvement of mechanical properties.

这项工作研究了两步烧结（TSS）和叠层结构对掺杂Cr ₃ C ₂ / VC的功能梯度WC-TiC-Al ₂ O ₃纳米结构复合材料的烧结行为和力学性能的关键作用。结果表明，在量身定制的TSS条件下可获得优异的机械性能，硬度为27.91±2.3 GPa，弯曲强度为1423.3±23.5 MPa。期望的机械性能归因于抑制的晶粒生长而没有致密化变质。与常规烧结（CS）相比，TSS在促进二次相增韧纳米颗粒在WC基体中的良好分散方面更为有效。铬₃ C ₂/ VC掺杂剂在最大化和改变WC-Al ₂ O ₃复合材料动力学窗口的温度范围中起着重要作用。主要的增韧机理是：Al ₂ O ₃裂纹偏斜，晶态Al ₂ O ₃，微裂纹，WC裂纹桥接和板状WC裂纹偏斜。由渐变结构引起的残余表面压应力也是改善机械性能的重要贡献。