International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Laser welding has become an indispensable manufacturing process, revolutionizing industries from automotive to medical devices with its precision, speed, and versatility. This advanced technique, which uses a high-intensity laser beam to melt and fuse materials, has seen significant technological advancements in recent years. These developments have expanded its applications, improved weld quality, and enhanced process control, making laser welding a cornerstone of modern manufacturing. This article provides an in-depth overview of the latest scientific developments in laser welding, including advancements in laser sources, process monitoring and control, material compatibility, applications, future directions, and challenges. It also integrates the most recent research from 2024 and 2025 to ensure the content reflects cutting-edge trends and innovations.

This study investigates the influence of distance and relative orientation of semi-elliptical twin surface cracks in cylindrical bars under tensile loading on the stress intensity factors (SIF). Finite element analysis was used to analyze the interactions between two identical cracks with different spacing (5-20 mm) and rotation angles (0°-180°). The results show that the crack orientation has a significant effect on the stress distribution patterns and stress intensity factor values, with a 45° rotation producing the highest SIF values, while a parallel orientation has a favorable shielding effect with significantly lower values. All configurations gradually converge to the reference value for a single crack at larger distances (20 mm), indicating decreasing interaction effects. These results can provide insights for the assessment of structural integrity, especially for components with multiple closely spaced defects, and provide a basis for the development of more accurate predictive models for fracture behavior in engineering applications.

The Cyber-Physical System (CPS) is one of the main concepts associated to the Industry 4.0 framework. The paper aims at analyzing the futures and architecture and technologies of CPS, retracting it in form its general conceptualization, to the interpretation in high relevant problem of welding manufacturing in context of Industry 4.0. The most recent approaches are based on empirical models or AI and rely on experimental data collection. On the other hand, the actuator shell control a certain parameter or parameter set. Under close consideration of the state of the knowledge to the problem of out-of-plane welding distortions, the aspects related to data sensing and actuating process parameters are analysed. However, due to the intensive development of the welding techniques und machines as well as the increasing focus on lightweight design pose a challenge that enters an unstudied parameter domain. To address this problem, a study was carried out using a combination of experimental and numerical methods. Based on the obtained results, the existing analytical expressions are supplemented and put into discussion. Essential findings, as well as the correlations between the occurring out-of-plane distortions and the welding process conditions and parameters are emphasized. Thus, the level of knowledge and the range of application of the existing analytical models are extended. On this basis, the development of highly effective deterministic-driven CPS in the context of Industry 4.0 is advanced.

A mathematical model is proposed, describing the movement of a gas bubble in a viscous liquid medium under the action of the Archimedean force. In addition to Archimedean forces and fluid viscosity it takes into account the influence of temperature and pressure of the fluid and of the gas in the bubble. Solutions have been obtained for the movements of a gas bubble in the conditions of a solidifying casting, considering the influence of the bubble size, the pressure in the liquid and the viscosity of the medium on the speed of movement. Software based on the FORTRAN language has been created, which implements the solutions of the model for specific values of the input parameters. The capabilities of the model are illustrated by numerical experiments under different conditions.

A mathematical approach is presented for estimation of inertia of thermocouples in unsteady heat transfer processes. The approach allows to estimate the systematic error in measured data and to make a first-order correction, bringing the measurement data significantly closer to the real ones. The efficiency of the method is illustrated by computer simulation of two examples from foundry practice. The symmetry of heat transfer processes is used to identify an important and determining parameter of the inertia of the thermocouple.

Simulation of gravity filling a metal mold with aluminum alloy (EN AC-46400 AlSi9Cu1Mg)

In this issue the main new opportunities in MAGMASOFT® 6.1 /last version of software package MAGMASOFT/ are presented and illustrated. The presentation will introduce you in all general innovations as general innovations in geometry perspective, new options for heat treatment of castings, new possibilities in continuous casting and a new innovation – MAGMA ECONOMICS. With the last option you can now also keep an eye on costs and emissions. With MAGMA ECONOMICS you can add a decision criterion to your decision base. Calculate the costs or look at the carbon footprint and make more informed decisions.

The latest version of MAGMASOFT software package – MAGMA6.1 is used to simulate and optimize a casting formation. The alloy AlSi7Mg was used for this purpose. The casting is intended for the production of a wire connector for high voltage power transmission networks. Die casting method is used. The results obtained from the stimulation of pouring and crystallization of the casting are presented. Based on the located defects and the analysis performed, changes of the technology were made, which ultimately ensure the formation of a defect-free and soundness casting.

In recent years, natural disasters have occurred almost annually in Japan, causing great damage. Power outages in disasterstricken areas have occasionally forced victims to resort to outdoor campfires or indoor candles for lighting. Prolonged bad weather during such events makes it difficult to safely secure lighting, which could have a negative influence on people’s health. To address this issue, we used white light-emitting diodes (LEDs) as the light source and fabricated handmade lanterns by filling a 500 mL plastic bottle with tap water and adding 1–2 drops of milk. In this study, an LED light source casing was constructed using a three-dimensional printer, achieving a stable light scattering effect. Red, green, blue, and yellow LEDs were used for the lantern, considering people’s preferences for colored handmade lanterns. An additional light source case was easily made from cardboard, and a bamboo light source case was also constructed.

Composite structural modifications based on hydraulic inorganic binders and foam glass aggregate fractions were prepared. Formwork moulds were developed for the moulding of composite test bodies using different technological approaches. A series of experimental specimens meeting the requirements for standard laboratory tests were obtained. The role of the technological regimes used in the formation of the structural characteristics and performance of the composites is examined. The existing possibilities for further modification and potential application of the obtained composite materials are analysed.

The article presents a comparison of different computational approaches used to study the surface treatment of a NiCrMoV steel with 0.55% Carbon content by a plasma jet. Metallographic observations show formation of martensite layer due to high cooling rate by heat transfer into the bulk steel. Heat affected zone (HAZ) was 1 mm deep and 10-12 mm wide. The treated surface maximum hardness was measured at 763 HV0.1 whereas untreated steel was at 210 HV 0.1. The computation indicates a hardening sink near the surface that went undetected in the experimental observations. The ability of the different computational approaches to explore the process related phenomena and to give reliable results is put into discussion.

High-speed machining (HSM) significantly influences the thermal dynamics of the cutting process, particularly in the toolworkpiece interaction zone. At elevated cutting speeds, the reduced tool-workpiece contact time minimizes heat transfer to the workpiece, concentrating thermal energy in the cutting zone. This results in localized material softening, reduced cutting forces, and enhanced process efficiency. This study investigates the thermal effects of HSM by experimentally turning C45 steel using a cubic boron nitride (CBN) tool at cutting speeds ranging from 800 m/min to 1800 m/min. Cutting forces were measured and analyzed in conjunction with temperature distributions within the cutting zone and tool. The experimental results were compared against predictions from the analytical Oxley machining model and numerical simulations using DEFORM software. The analysis revealed the dependence of cutting speed on cutting zone thermal properties, providing insights into material behavior under high-speed conditions. Furthermore, the study identified optimal cutting speeds that balance thermal effects and cutting process stability. These findings contribute to the definition of appropriate high-speed machining parameters, ensuring effective heat dissipation and stable tool performance.