This paper presents the application of the electromagnetic field as a tool for metal sheet cutting. The experiments showed that one can easily adapt the conventional cutting equipment to the electromagnetic cutting technology and thereby eliminate the mechanical work of the punch and the press. Two methods exploiting the electromagnetic field as the tool for cutting sheet metal were used. In one of the methods the cutting element was a die while in the other method a punch was used for cutting. Owing to the high quality surface of the cut obtained by each of the methods the cutting process does not entail additional costs for removing burrs. The shape of the surface of the cut is different than the one obtained by traditional blanking – no zones characteristic of the latter are present here. In the case of both materials, the rollover of the sheet surface is much larger and longer than in the conventional method. In comparison with the conventional method, the electromagnetic machining technology ensures high quality of the surface of the cut and can be successfully used in the industry.

Both graphene, a single-atom-thick layer, and its derivative, reduced graphene oxide (rGO), are highly promising materials with a wide range of applications due to their exceptional mechanical, electrical, and thermal properties. However, the application of graphene in its natural form in engineering practice is challenging, which is why a three-dimensional structure is preferred. Additionally, a very strong bond with the metal substrate is highly desirable. Here, we present a method for obtaining such micrometer-thick 3D rGO coatings on various metal alloys. This bulk material coating inherits, to some extent, the exceptional properties of single-layer graphene. The method for obtaining 3D rGO is based on the preliminary preparation of the metal surface using an argon cold plasma and the application of rGO using a pulsed electric current. A good bond between the layer and the substrate has been demonstrated, confirmed both by TEM, where no porosity was found, and in a number of other studies, including XPS, nanoindentation, and scratch testing. To better determine the quality of the obtained bond with the substrate, a resistance measurement method was used during tensile-compression tests. The 3D rGO coating developed can be used in many practical engineering applications where the high strength or other remarkable properties of graphene are particularly desirable.

The plastic treatment of products reduced to sizes corresponding to the microscale poses difficulties, due to the occurrence of the so-called size effect, which is responsible for the different behavior of the material during the realization of microforming. In this study, a constitutive equation was elaborated taking into account two types of size effects, with the use of a surface model as well as a composite material model. The influence of the size effect referring to both the material grain size and the geometric scaling of the sample size on the material’s flow stresses was considered. The surface model took into account the different grain shapes present in actual polycrystalline materials. After the application of the presented model for titanium Grade 2, a good agreement of the experimental results with the FEM simulation results was obtained. Thus, the proper FEM modeling of microforming processes should be conducted with the use of a material model, taking into account the occurring size effects.

This article presents a study on symmetric cyclic torsion with the application of electric pulses and their effect on the formability of α-brass CuZn30 at room temperature. Preliminary tests were carried out using a conventional monotonic torsion test. The obtained results served as a reference for the subsequently conducted symmetric cyclic torsion tests. Then, under analogical deformation conditions, tests were conducted with the application of electric pulses featuring various parameters: different pulse durations and different periods, i.e., intervals between successive pulses. Microstructural studies of the deformed material were conducted, including examinations using a microscope equipped with an electron backscatter diffraction (EBSD) detector. Based on the results, it was found that the application of electric pulses during cyclic torsion tests consistently leads to a reduction in stress compared to cyclic torsion tests conducted at ambient temperature without current flow. In most cases, it also results in an increase in strain compared to tests without the application of electric pulses. The electroplastometric torsion tests carried out in this study within the bulk forming process are the first of their kind to combine cyclic torsion with electrically assisted forming (EAF). The proposed combination may lead to the development of new deformation methods in real manufacturing processes.

This article presents the results of research on electrically assisted forming (EAF) in the process of cyclic oscillatory torsion of CuZn30 brass. Experiments were conducted using pulsed electric current with varying parameters: pulse durations of 0.5, 2.5, and 5 ms, and pulse intervals ranging from 0.5 to 30 ms. Reference data for the electrically assisted torsion tests were obtained from conventional tests performed under identical conditions without current flow. A pronounced thermal effect was observed for specific current parameters. To accurately determine the impact of temperature rise on the deformability of CuZn30 brass during cyclic torsion, the authors conducted additional tests at elevated temperatures—corresponding to the average temperatures recorded during the EAF trials—without current application. In all investigated cases, EAF during cyclic oscillatory torsion led to a flow stress reduction ranging from nearly 8% to almost 25% compared to current-free trials. Furthermore, applying current parameters where the pulse interval exceeded the pulse duration resulted in a significant increase in strain to failure, ranging from nearly 25% up to 110% relative to the reference samples. The study also examined isophase current characteristics (where pulse duration equals pulse interval), which yielded results that clearly deviated from other configurations. The application of isophase pulses triggered a different material response, leading to a degradation of deformability by more than 21%. The presented research and findings may contribute to the further development of novel, energy-efficient, and advanced manufacturing processes in metal forming.