In this article, the influence of electropulsing on the machinability of steel S235 and aluminium 6060 has been studied during conventional and electropulsing-assisted turning processes. The machinability indices such as chip compression ratio ξ, shear plane angle ϕ and specific cutting energy (SCE) are investigated by using different cutting parameters such as cutting speed, cutting feed and depth of cut during electrically-assisted turning process. The results and analysis of this work indicated that the electrically-assisted turning process improves the machinability of steel S235, whereas the machinability of aluminium 6060 gets worse. Finally, due to electropluses (EPs), the chip compression ratio ξ increases with the increase in cutting speed during turning of aluminium 6060 and the SCE decreases during turning of steel S235.

The aim of this study is to report the use of non-conventional material removal process technique. It was found that electropulses (EPs) assisted drilling process improves the material machinability based on the eletroplastic influence. The influence of EPs in drilling process is studied by combining different feed rates, drills diameters and current densities in 7075 aluminium and 1045 carbon steel. The results show that the electrically assisted drilling process improves material machinability, decreases the specific cutting energy up to 27% in aluminium and 17% in steel.

In the forging industry, surface quality and surface treatments of dies are crucial parameters to extend their life. These components are usually machined by milling or by Electrical Discharge Machining (EDM), and the final surface roughness depends on the machining techniques and operational conditions used in its fabrication. After milling, a nitriding treatment is widely applied to extend its service life. Nevertheless, no scientific report that informs about nitriding after EDM has been found. Accordingly, this work focuses on the wear and friction behavior of pins made of brass and medium carbon steel sliding over AISI H13 discs, made by wire EDM in the conditions of finishing and roughing. The discs are plasma nitride, and their effect on the wear during pin-on-disc tests is evaluated. In this sense, the analysis of the surface damage for the different pins will help us to understand the service life and wear evolution of the forging dies. The results show that plasma nitride reduces the friction and prevents the degradation of the pin, independently of the material of the pin, when sliding over finishing and roughing EDM conditions.

Grinding energy efficiency depends on the appropriate selection of cutting conditions, grinding wheel, and workpiece material. Additionally, the estimation of specific energy consumption is a good indicator to control the consumed energy during the grinding process. Consequently, this study develops a model of material-removal rate to estimate specific energy consumption based on the measurement of active power consumed in a plane surface grinding of C45K with different thermal treatments and AISI 304. This model identifies and evaluates the dissipated power by sliding, ploughing, and chip formation in an industrial-scale grinding process. Furthermore, the instantaneous positions of abrasive grains during cutting are described to study the material-removal rate. The estimation of specific chip-formation energy is similar to that described by other authors on a laboratory scale, which allows to validate the model and experiments. Finally, the results show that the energy consumed by sliding is the main mechanism of energy dissipation in an industrial-scale grinding process, where it is denoted that sliding energy by volume unity decreases as the depth of cut and the speed of the workpiece increase.

This article describes the development of a methodology to measure the specific cutting energy (SCE) in drilling. The SCE allows characterizing and the machining process, thus obtaining a technologic approach that allows to carry out a planning of the chip removal process. The main frame of this machine consists of a pedestal drill, instrumented with: a meter, a motor that controls the spindle speed, safety elements such as limit switches and an active power meter coupled to the drill motor. The mechanical power is calculated indirectly through the active power. To this end, it must have a previous calibration with a torque dynamometer to reoced theoutput curve and, subsequently, display the relationship between the mechanical power and the active electrical power. To validate the capability of this method, the EEC of three different materials is evaluated, an aluminum 7075-T6 and the steels C45E y 34CrNiMo6. It has been verified that the estimated SCE values correspond to those described by the literature. The influence of several parameters, like the cutting speed and the feed rate, on the SCE allows to estimate the sensitivity of this method. Finally, this works shows that the SCE in steel increases with the increase of the feed rate, whereas in aluminum the behavior is the opposite, the SCE decreases as the feed rate increases. Keywords: Specific cutting energy, material removal rate, cutting power, feed rate, drilling.