Influência do ar comprimido resfriado no processo de fresamento do aço H13 endurecido com ferramentas barril e topo esférico

Abstract

Due to the increasing complexity of the machining processes, the present research aims to evaluate the efficacy of cold air in hardened H13 steel milling at 48 HRC, employing both barrel and ball nose end mills for machining on double-inclination surfaces. The main goal of this study is to enhance machining productivity while reducing environmental impacts and operational costs. Additionally, the adoption of barrel end mills is explored as one of the strategies to reduce machining time without compromising the quality of the final product. The temperatures and maximum flank wear were monitored during the tests, and the 2D surface roughnesses were measured. The cooling methods of the chip-tool interface adopted were compressed air at 15 °C and cooled compressed air at -26 °C by a vortex tube. After the tests, the 3D surface topographies of the samples were examined with interferometry, and cutting tools wears were assessed using a scanning electron microscope (SEM) with energy-dispersive X-ray (EDX) analysis. The results of the tests showed that the type of cooling did not significantly impact the surface roughness or maximum tool flank wear. All tools experienced coating loss, exposing the base material. There was also machined material adhesion on the cutting edges, mainly when machining with a ball nose end mill under compressed air without cooling. Specifically with the barrel end mill, material from the tool was pulled out, which may have intensified the vibrations during machining. The cold compressed air kept the temperature of the specimen closer to room temperature and improved chip breaking.