Efeito da texturização em ferramentas de pcd no torneamento de Alumínio 2011-t4

Abstract

In recent years, researchers have tried to compile studies on the effects of texturing on cutting tools. There is a clear convergence of the conclusions, however, there are still parameters whose results drastically diverge among the authors. One of the possible causes of such divergent results is the difference between the properties of the materials studied by each researcher. Therefore, the effects of textures on materials studied in smaller numbers in the literature end up being masked, as is the case of aluminum, a material that, despite being widely used in industries, corresponds to only 16% of the materials studied in the last 5 years. The application of textured tools in aluminum machining combined with a high-strength tool such as PCD becomes highly viable, because in this combination there is no significant tool wear, unlike in most cases where there is rapid tool wear that consumes the texture in a short machining path, nullifying its effect. Thus, this work carried out turning tests in 2011-T4 aluminum alloy with PCD tools with different types of texture (parallel and perpendicular channels to the main cutting edge), varying the lubri-cooling condition (dry and with the addition of MoS2) and cutting speed. Tests with non-textured tools were also performed for comparisons. The textures were machined by a femtoseconds Ti:sapphire laser, varying the direction, depth and width of the channels. The output parameters considered in the experiments were the cutting forces, cutting temperature, workpiece surface roughness and chip morphology. Favorable conditions for texture production and their behavior during turning were observed. The textures helped to break the chips and consequently the dissipation of the heat generated. The presence of lubricant avoided the material clogging inside the textures, reducing friction, so the MoS2 favored the cut in relation to the reduction of forces and temperatures, however there was no improvement in relation to the roughness of the piece. It was observed that textures have a large influence on the feed force, but this component was only a small percentage of the machining force, and therefore the small influence on the cutting force was what determined the final result in the machining force. Textures with channels perpendicular to the main cutting edge with lubricant showed the best results when compared to non-textured tools: the textures with smaller dimensions reduced the machining force by more than 7 %, and the temperature by 9 %, while the textures with larger dimensions reduced the surface roughness parameter Ra by 49 %. Keywords: Laser texturing, PCD tools, Aluminum 2011-T4 alloy, MoS2.