Micro end-milling of channels using ultrafine-grained low-carbon steel

During micromachining, the interaction between the cutting tool and the workpiece material may cause damages on the machined surface related to material deformation. It would be interesting that the workpiece microstructure suits the scale of the cutting parameters. Very little has been investigated on how a metallurgically modified material responds to microcutting. This research evaluated the effect of an ultrafine-grained material in the micromilling of grooves. Dual-phase low-carbon steel (ferrite-pearlite) was submitted to warm rolling for grain refinement (from 11- to 0.7-mu m size of ferrite grains). The effect of tool cutting edge radius (r(e)), feed per tooth (f(t)), tool diameter, and speed cutting upon surface roughness and burr formation during end-milling of the original material and the modified one was evaluated. The ultrafine-grained material showed better results of surface finishing and presence of burrs when compared to the original dual-phase material. The metallurgical modification of low-carbon steels by grain refinement favored for micromachining of grooves, making it possible to extend applications of this class of steels.