DLC表面特性对高速钢耐磨性的影响

EFFECT OF DLC SURFACE BEHAVIOUR ON WEAR RESISTANCE OF HIGH SPEED STEEL

在高速钢基体上沉积了三种不同的DLC薄膜,厚度均为2μm。利用原位纳米力学测试系统测试了DLC薄膜表面纳米硬度,采用德国标准用洛氏硬度计及金相显微镜方法测试了DLC薄膜与基体的结合强度。在MM200摩擦磨损试验机上比较了三种DLC试样对铸铁合金的摩擦磨损性能,利用三维超景深显微镜对DLC试样的磨痕面积及形貌进行测量与分析,并以磨痕面积评判耐磨性。结果表明:稳定磨损阶段各DLC试样在不同的润滑条件下摩擦系数均比较低;硬度及结合强度对DLC的耐磨性能有较大影响,硬度和结合强度适中时摩擦性能最好,而当硬度较低时耐磨性最差。

Three different types of DLC films with the thickness of about 2 μm were prepared on the surface of high speed steel. The nanohardness of these DLC films was tested by In-Situ Nano- mechanical Test System. The adhesive strength of DLC films to substrates was measured by using Rockwell hardometer and metallographic microscope according to German Standard. The wear resist- ance of the three DLC samples running against cast iron alloy was investigated by using MM-200 fric- tion and wear tester, also the wear track areas and micrographs of DLC samples were calculated and analyzed by three dimensional ultra depth of field microscope. The wear track areas were adopted to assess the wear resistance level. It was revealed that under various lubrication conditions the friction coefficient of DLC samples hold in a low level during stabilized wearing, the wear resistance of DLC samples were deeply affected by surface hardness and interfacial adhesive strength. The wear resist- ance showed the best performance when hardness and adhesive strength combined well, however, it would be in the worst state due to very low surface hardness of DLC.