Automated electric drive for the control system of two-coordinate welding machine

Two-coordinate welding machine is used to obtain welds on various elements of high quality metal structures. The main disadvantage of the existing equipment is that the work on this machine is currently performed manually. This operation is quite dangerous and monotonous. In addition, hydraulic drive is used as the main drive of the system. Replacement of the hydraulic drive of a two-coordinate welding machine with an electric drive is substantiated in order to increase the efficiency of the entire system. The authors have developed an automated system for a two-coordinate machine for welding embeds, controlled on the basis of a programmable logic controller. A functional diagram of an automated electric drive for such machine was proposed. The design of the object’s electric drive was carried out. The necessary elements of the developed automation system were selected. On the basis of the technological process, an algorithm has been developed that allows automating the process of embeds welding. The developed algorithm provides the necessary security measures, carrying out self-diagnostics at the stage of system startup. In order to check the performance of the developed algorithm, an automated electric drive was simulated using the MATLAB Simulink software. The developed system contains two internal and three external circuits that control the required parameters: speed, current, torque, flux linkage and force. The dynamic characteristics of the presented parameters are obtained, confirming the operability of the developed automated electric drive system. An economic calculation of the automation system proposed for implementation has been carried out. The total costs for the modernization will amount about 55 thousand rubles with a payback period of about one year.

Preventing Evaporation Products for High-Quality Metal Film in Directed Energy Deposition: A Review

Directed energy deposition (DED), a type of additive manufacturing (AM) is a process that enables high-speed deposition using laser technology. The application of DED extends not only to 3D printing, but also to the 2D surface modification by direct laser-deposition dissimilar materials with a sub-millimeter thickness. One of the reasons why DED has not been widely applied in the industry is the low velocity with a few m/min, but thin-DED has been developed to the extent that it can be over 100 m/min in roller deposition. The remaining task is to improve quality by reducing defects. Thus far, defect studies on AM, including DED, have focused mostly on preventing pores and crack defects that reduce fatigue strength. However, evaporation products, fumes, and spatters, were often neglected despite being one of the main causes of porosity and defects. In high-quality metal deposition, the problems caused by evaporation products are difficult to solve, but they have not yet caught the attention of metallurgists and physicists. This review examines the effect of the laser, material, and process parameters on the evaporation products to help obtain a high-quality metal film layer in thin-DED.

Preventing Evaporation Products for High-quality Metal Film in Directed Energy Deposition: A Review

Directed Energy Deposition (DED) is a process that enables high-speed deposition with a sub-millimeter thickness using laser technology. Thus far, defect studies on additive manufacturing, including DED, have focused mostly on preventing pores and crack defects that reduce fatigue strength. On the other hand, evaporation products, fumes and spatters, generated by the high energy have often been neglected despite being some of the main causes of porosity and defects. In high-quality metal deposition, the problems caused by evaporation products are difficult to solve, but they have not yet caught the attention of metallurgists and physicists. This review examines the effect of the laser, material, and process parameters on the evaporation products to help obtain a high-quality metal film layer in thin-DED.

Regeneration of Metal Radioactive Waste from Radiochemical Industries for Metal and Alloy Recycling Purposes

The paper proposes a processing method for metal radioactive waste (high alloyed stainless steel and its alloys) containing transuranic radionuclides. This type of waste is generated during operation and decommissioning of SNF reprocessing equipment at radiochemical production facilities. To ensure the recycling of valuable components, decontamination and conditioning of the regenerated ingots to high-quality metal is arranged in a two-staged process involving MRW remelting: its first stage involves in-depth metal decontamination under a layer of a refining flux, whereas the second stage provides for additional metal treatment to remove radioactive and stable impurities, as well as metal alloying to make up for the "burnt out" valuable components and to level its chemical composition. The process is implemented at an enterprise specialized in RW processing having appropriate infrastructure facilities and licenses authorizing relevant operations with radioactive materials. Metal radioactive waste regeneration results in a grade metal, which in terms of its residual radioactive contamination level can be released from radiation control and admitted to unrestricted use. It has been experimentally demonstrated that ESR, when used for MRW decontamination purposes, allows to obtain high-quality steel suitable for future reuse.