刀具用硬质合金刀片表面等离子渗氮涂层制备及其耐磨性能研究

Study on Preparation of Plasma Nitride Coating on the Surface of Cemented Carbide Blade and its Wear Resistance

在氮气气氛、高压条件下,利用等离子渗氮技术于刀具用硬质合金刀片表面制备氮化物涂层。利用X射线衍射仪(XRD)表征涂层物相,显微硬度计测试涂层显微硬度,扫描电镜(SEM)表征涂层表面及截面微观形貌。通过对比硬质合金试样和涂层试样的摩擦系数,衡量涂层耐磨性能;通过观察摩擦磨损实验后表面微观形貌,研究硬质合金和涂层试样的摩擦磨损机理。结果表明:涂层物相以TiN为主,层厚5μm左右;涂层与基体间紧密结合,无明显间隙与裂纹;硬质合金基体的摩擦系数在0.4左右,且出现较大波动,而涂层摩擦系数稳定在0.2左右。在硬质合金表面制备的等离子渗氮涂层可有效提高基体的耐磨性能。

Plasma nitride coating was prepared on the surface of cemented carbide blade under the conditions of nitrogen atmosphere and high pressure. The phase composition of the coating was characterized by XRD,its micro-hardness was tested by a micro-hardness tester, and its microstructure on surface and sec- tion was observed by SEM. Wear resistance of the coating was evaluated by contrasting friction coefficient between cemented carbide sample and coated sample. The wear mechanism of cemented carbide and coated sample was studied based on friction and wear surface morphology. The results show that the coating was mainly composed of TiN of about 5 pm layer thickness. The coating is tightly bonded to the substrate with- out obvious gap and crack. The friction coefficient of cemented carbide substrate is about 0.4 with relative- ly large fluctuation,while the coating has stable friction coefficient around 0.2. Plasma nitride coating on cemented carbide surface can effectively improve the wear resistance of the substrate.