Search Results (4)

Tungsten carbide is currently the most widely used tool material for machining difficult-to-machine materials, such as titanium alloys and nickel-based super alloys. In order to improve the performance of tungsten carbide tools, surface microtexturing, a novel technology that can effectively reduce cutting forces and cutting temperatures and improve wear resistance, has been applied in metalworking processes. However, when fabricating the micro-textures such as micro-grooves or micro-holes on tool surfaces, the significant decrease in material removal rate is a major obstacle. In this study, a straight-groove-array microtexture was fabricated on the surface of tungsten carbide tools via a femtosecond laser with different machining parameters including laser power, laser frequency, and scanning speed. The material removal rate, surface roughness, and the laser-induced periodic surface structure were analyzed. It was found that the increase in the scanning speed decreased the material removal rate, whereas increasing the laser power and laser frequency had the opposite effects on the material removal rate. The laser-induced periodic surface structure was found to have a significant influence on the material removal rate, and the destruction of the laser-induced periodic surface structure was the reason for the reduction in the material removal rate. The results of the study revealed the fundamental mechanisms of the efficient machining method for the fabrication of microtextures on ultrahard materials with an ultrashort laser. Full article

This paper explores the influence of micro textures on cutting performance of polycrystalline cubic boron nitride (PCBN) tools from two aspects, that is, tool wear and machined surface roughness. By designing micro-hole textures with different forms and scales on the rake face of tools when PCBN tools turn hardened steel GCr15, and combining finite element analysis (FEA) technology and cutting experiments, the cutting performance of micro-textured tools is simulated and analyzed. This paper analyses the influence of micro textures on tool wear and machined surface roughness by analyzing cutting force, Mises stress and maximum shear stress of tool surface. Results of finite element analysis (FEA) and cutting experiments show that the reasonable micro-hole textures can significantly alleviate tool wear and improve machined surface quality when compared with the non-textured tools. Besides, the size of micro-hole textures on the rake face play an important role in reducing the cutting force and tool wear. This is mainly because micro-hole textures can reduce cutting force and improve tool surface stress. Finally, by designing reasonable micro-hole textures on the rake face, the problems of bad roughness of machined workpiece and severe tool wear of PCBN tools in cutting GCr15 material are solved. Consequently, the paper shows that micro-hole textures have a positive effect on improving the cutting performance of tool. Full article

This paper applies micro textures to the rake face of PCBN (Polycrystalline Cubic Boron Nitride) tools, including three types of micro textures that are microgroove textures vertical to the cutting edge, microgroove textures parallel to the cutting edge, and microhole textures. In this paper, the effects of different cutting speeds on the surface quality of hardened bearing steel GCr15 by dry turning with non-texture PCBN tools and micro-texture PCBN tools are studied, and the surface roughness values obtained by different micro textures were compared and analyzed. The results showed that, compared to that of non-texture tools, the influence degree of the micro-texture tools on the machined surface roughness was different. The microhole texture and vertical microgroove texture were able to effectively reduce the surface roughness of the workpiece, and microhole texture had the best effective influence on surface roughness, but the parallel microgroove texture increased surface roughness. The influence of cutting speeds on surface roughness was different due to different types of micro textures. The influence of micro textures on surface roughness has huge potential for tool applications. Full article

To enhance the friction and wear performance of cemented carbide, textured microholes were machined on micro Electron Discharge Machining (EDM) on the tool rake face, and Calcium Fluoride (CaF₂) powders were burnished into the microholes. The friction and wear characteristics of the microhole-textured tool filled with CaF₂ were investigated using sliding friction tests and dry cutting tests. Results exhibited that the working temperature could affect the tribological performance of the microhole-textured tool filled with CaF₂ due to the temperature-sensitive nature of CaF₂. There is no obvious lubrication effect for the textured tool filled with CaF₂ at room temperature, while it was shown to be more effective in improving tribological property at a cutting speed of higher than 100 m/min with a corresponding to cutting temperature of 450 °C. The possible mechanisms for the microhole-textured tool filled with CaF₂ were discussed and established. Full article