Laser Surface Textured Cemented Carbides for Application in Abrasive Machining Processes

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Cutting effectiveness of abrasive tools is directly related to their intrinsic surface topography resulting from the abrasive grains protruding out of the tool surfaces. The fundamental concept of this project inherits from the study of the behavior of single abrasive grains in the abrasive machining processes. However, it is not easy to exclude the influences of other adjacent abrasive grains on the associated cutting surfaces. Therefore, it is meaningful to conceive an approach to isolate or fabricate single grains on the tool cutting surface. In this regard, the use of more conventional hard materials, e.g. cemented carbide, might be proposed as alternative for expensive tool materials, as long as the surface topography features of current abrasive tools can be replicated at the corresponding length scales and the mechanical properties can also meet such cutting requirements. In a previous study of abrasive tools (CBN honing stone as example), topographical features of the cutting surfaces, especially the geometry and distributions of the protruding grains were statistically characterized. Surface topography of the novel cemented carbide tools will be conceived and designed based on the results of the previous study. Subsequently, these geometrical features will be replicated on cemented carbides using the advanced laser surface texturing (LST) technology. Results of previous fundamental research of laser-matter reaction mechanism are the base for LST process design, to obtain high geometrical precision, to improve surface integrity and to avoid surface damage. Afterwards, mechanical properties of these novel tools shall be enhanced through coating technology. The compatibility of the coatings on the laser machined surfaces shall be studied and improved. Finally, performance of the new tools will be validated and compared with traditional abrasive tools by various implementations, including cutting tests, tribological tests and investigations of mechanical properties.