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用控制烧结工艺制备了均质基体结构与梯度基体结构的WC-(W,Ti)C-(Ta,Nb)C-Co硬质合金,采用化学气相沉积工艺在合金表面涂上TiCN/Al2O3/TiN涂层,制备成相应的涂层硬质合金及刀片。运用金相观察、扫描电镜分析、三点抗弯强度测试及切削性能测试,研究了梯度基体结构对涂层WC-(W,Ti)C-(Ta,Nb)C-Co硬质合金的组织与力学性能影响。结果表明,采用梯度烧结工艺,可以在合金的表层形成梯度韧性区,该韧性区可以提高裂纹扩展阻力。所制备的梯度基体结构合金的抗弯强度明显超过均质基体结构合金,而相应涂层硬质合金刀片在保持耐磨性能的同时能显著提高抗冲击性能。
The WC- (W, Ti) C- (Ta, Nb) C-Co cemented carbide with homogeneous matrix structure and gradient matrix structure was prepared by controlling the sintering process. The alloy surface was coated with TiCN / Al2O3 / TiN coating, prepared into the corresponding coated cemented carbide and blade. The microstructure of WC- (W, Ti) C- (Ta, Nb) C-Co cemented carbide with gradient matrix was studied by means of metallographic observation, scanning electron microscopy, three-point bending test and cutting test. And mechanical properties of the impact. The results show that the graded toughness zone can be formed on the surface of the alloy by the gradient sintering process, and the toughness zone can improve the crack propagation resistance. The flexural strength of the prepared gradient matrix alloy significantly exceeds that of the homogeneous matrix alloy, while the corresponding coated cemented carbide inserts can significantly improve the impact resistance while maintaining the wear resistance.