纳米TiN对WC-Co硬质合金组织和力学性能的影响

Effect of Nano-TiN on Microstructure and Mechanical Properties of WC-Co Cemented Carbide

采用真空烧结方法制备添加纳米TiN的WC-Co硬质合金材料,研究不同添加量纳米TiN对硬质合金组织和性能的影响。结果表明:纳米TiN添加量未超过1%(质量分数)时,纳米粒子主要分布在晶界和相界处,可明显改善WC-Co硬质合金组织结构,并使硬质合金的抗弯强度和硬度得到提高。添加纳米TiN,不利于改善硬质合金的断裂韧性。纳米TiN添加量为1%时,材料的综合力学性能最好:抗弯强度1493MPa,硬度92.5,断裂韧性12.1MPa·m1/2。

The WC-Co-based cemented carbide was fabricated by vacuum sintering, and the effect of nano-TiN on microstructure and mechanical properties was studied. The results show that, when the nano-TiN addition is not beyond 1% （ mass fraction）, the nano-TiN particles are located at grain boundary and phase boundary, which effectively improves the microstructure, bending strength and hardness of the cemented carbide. The fracture toughness of the cemented carbide isn＇t improved by adding nano-TiN. When the nano-TiN addition is 1%, the material shows the best mechanical properties with the bending strength of 1 493 MPa, hardness of 92.5 and fracture toughness of 12.1 MPa.m^1/2.