This article deals with the effect of quenching and tempering on the hardness and microstructure of 42CrMo4 steel. All investigated samples were water quenched from an austenitizing temperature of 820 °C. After quenching, the samples were tempered at 610 °C, for 30 minutes and for 60 minutes. After the heat treatment, the cross-sectional hardness of the samples was measured. The hardness was measured us (…)
This paper presents a comprehensive application of the Multi-Criteria Decision-Making (MCDM) approach to evaluate and rank different models of welding goggles. The study uses both the Mean Weight and Entropy Weight methods in conjunction with five different MCDM techniques—TOPSIS, CODAS, COPRAS, SAW, and MOORA. These methods provide an insightful comparison and robust ranking of various goggle models. T (…)
This research aims to improve the sustainability and mechanical properties of concrete by using partial replacement of cement with Ground Granulated Blast Furnace Slag (GGBFS), Alccofine (AL), and Metakaolin (MK). The study compares the effects of different proportions of GGBFS (0-50%), Alccofine (0-20%), and Metakaolin (0-15%) on the compressive, tensile, and flexural strength and at curing ages of 7th (…)
Abrasive Waterjet Machining (AWJM) is one of the widely used non-traditional machining process to cut the hard materials like aluminium metal matrix composites (AMMCs) and the materials which are very difficult to machine using conventional machining due to their high hardness and tendency to cause tool wear. Present work two popular multi criteria decision making (MCDM) techniques Complex Proportional (…)
In this study predictive models are developed for moisture ratio in the drying process of grapes using a desiccant rotary dryer. Response Surface Methodology (RSM) and Genetic Programming (GP) are employed to capture the relationship between critical drying parameters—temperature, airflow velocity and time—and the moisture ratio. The RSM model demonstrated high accuracy with a correlation coefficient of (…)
This research investigates the tribological characteristics of SS316L produced through Laser Powder Bed Fusion (LPBF), emphasizing the influence of testing temperature, sliding velocity, and loading conditions. The findings demonstrate that the friction coefficient escalates with increased temperatures (150°C and 250°C), whereas the wear rate remains invariant, presumably attributable to the establishme (…)
This study introduces Gaussian Binary Particle Swarm Optimization (G-BPSO), designed to address binary optimization challenges effectively. G-BPSO employs new transfer functions of the Gaussian type derived from the power functions to enable mapping of real-valued vectors of individual encodings into binary form. This ensures smooth change between steps and improved convergence. To assess the effectiven (…)
In this work, the application of various machine learning (ML) algorithms for predicting tensile strength based on welding parameters in AA2014-T6 aluminium alloy joints is studied. Six ML models namely linear regression, AdaBoost regression, random forest regression, support vector regression (SVR), multi-layer perceptron regression and gaussian process regression (GPR) are considered. The comprehensiv (…)
Friction stir welding (FSW) can be a solution in solving the problem of joining thermoplastic polymers which are difficult to do with fusion welding. Selection of the proper FSW connection parameters can produce optimal connection quality in HDPE material joints. In friction stir welding, the heat of welding is used to raise the temperature of the material from its initial state to the solid state tempe (…)
The article deals with the determination of the influence of the speed of hard metal layers welding, with a focus on the evaluation of the abrasive wear of the layers formed by the tubular wire welding technology. The layers were wound with filled wire manufactured by ESAB under the trade name Fluxofil 58. Two different winding speeds of v=125m/min and a speed of 18m/min were used to produce the samples (…)
Thanks to its carbon-free nature, it is possible to say that hydrogen is a potential fuel for future automotive systems. Its main favourable properties include high burning rate, wide range of flammability and low ignition energy. In combination with hybrid electric technology, the hydrogen combustion engine has the potential for further development with the goal of maximum efficiency in energy conversi (…)
Presented paper is focused on the experimental welding of aluminium alloys – the additively manufactured material AlSi10Mg and the conventional alloy AW-5754. The experimental electron beam welding was conducted in collaboration with First welding company, Inc. The objective of the experiment was to create a weld joint between aluminium alloys prepared by additive and conventional methods, evaluate the (…)
The study showcases findings from an investigation into the chemical composition and morphology of nanocomposite materials employed in the production of dental implants. By utilizing clinical strains of microorganisms isolated from patients with implant infections (including Bacteroides fragilis, Porphyromonas melaninogenica, Actinomyces spp., and Staphylococcus aureus), the authors of the paper analyze (…)
Galvanic plating is one of the most widespread methods of surface treatment of metal parts. The process consists of immersion of modified parts in an electrolytic bath. These processes produce wastewater with a high metal content. One of the methods of reduction metal content in water is sorption on a solid layer. Natural zeolites in natural form, but also in modified form, can be used for these purpose (…)
High pressure die casting is a precision casting method that comes closest to the ideal effort of directly transforming the base material into a finished product. Casts produced by high pressure die casting are characterized by high quality, even if they are prone to internal inhomogeneity. The internal inhomogeneity of the casts is, among other things, caused by entrainment of air, gases and vapors ins (…)
The article deals with the investigation of tribological properties of polycarbonate (PC) material produced by 3D printing using Fused Deposition Modelling (FDM) technology under different layer deposition strategies and their subsequent testing for abrasive wear. The aim of the experiment was to compare the effect of different layer deposition strategies in the FDM process on the abrasive wear of the m (…)
Industry 4.0 marks a major transformation driven by digitization, automation, and smart technology integration in production, significantly impacting human resources and reshaping work environments and employee management practices. Both, employees and managers must adapt to these technological shifts, which alter traditional approaches to core areas of human resource management, presenting new challeng (…)
This study presents the Piecewise Constant Curvature (PCC) kinematic model of a two-segment continuum robot, offering a clear and illustrative approach to deriving the kinematics of a soft manipulator. Analytical expressions are developed to relate the endpoint positions of the robot’s pneumatic arm segments to the lengths of its pneumatic muscles. The kinematic model has two contrasting features: it is (…)
Machining technologies are constantly evolving in line with new material development strategies, with further advances in cutting tools accelerating these changes even further. Growing demands for increased productivity and production efficiency have led us to today's advanced level of technology. Recently, steel structures made of thin sheets and strips, which are processed by bending, three-dimensiona (…)
This article is focused on the construction of a stand-alone residential 5-kW hybrid power system to feed different domestic loads at a typical house in Thi-Qar City, Iraq, including lighting loads, Table fan, Smartphone charger, TV, Microwave and Cooler. The stand-alone residential 5-kW hybrid power system consists of PV generator, PEMFC, storage batteries, Electrolyzer and hydrogen tank. The battery a (…)
This article considers the development of a mathematical model of electrochemical grinding for processing precision components operating at varying loads. The combination of processes (for example, the mechanical and electrochemical material removal processes) significantly improves operation control capabilities by increasing the number of control inputs and selected input variables. The results of the (…)
In this work, the aerodynamic analysis of the original and modified Ahmed body was done. The principle of modification was the chamfer angle on the back sides of the Ahmed body like a boat tail, which was expected to decrease the magnitude of the drag force. The value of the aerodynamic coefficients was carried out using CFD modelling and data were validated in wind tunnel measurements. For those measur (…)
Currently, emphasis is placed on the ever-higher accuracy and speed of measuring the geometric accuracy of CNC machine tools. Achieving the highest possible accuracy is often time-consuming, which results in higher financial costs. The purpose of this study was to verify the suitability of the dynamic measurement of the position CNC machine based on laser interferometry using angular optics concerning (…)
The article provides practical insights into the development of a specialized machine for automating the assembly of components based on customer-specified parameters. The initial design undergoes a risk analysis in accordance with the EN ISO 13849 standard, ensuring safety compliance. For the software aspect, we create sequences and algorithms for the machine's individual components using standardized (…)
Investigating vibrations in mechanical transmission systems to detect and identify the causes of abnormal vibrations remains a prominent focus for researchers. Within industrial transmission systems, rolling bearings play a pivotal role. Utilizing the envelope spectrum of vibration signals to diagnose faults in rolling bearings proves highly reliable due to the bearings' mechanical properties. Under con (…)
Determining the particle size distribution of water mist is necessary for a wide range of industrial applications or experimental measurements. Particle size defines the ability of water mist to absorb heat, absorb or scatter heat radiation, inertize the environment, reduce environmental dust, regulate odor, etc. The paper presents the principle of measuring droplet size distribution using laser diffrac (…)
This paper focuses on application of fuzzy logic to enhance induction motor drive performance in case where the measured stator currents are distorted by Gaussian noise. For different load torques, the fixed proportional-integral (PI) speed controller provides an undesired drive performance for both transient and steady-state responses. At first, load torque is computed thanks to extended-Kalman-filtere (…)
The nuclear power plants in Eastern Europe face problems with supplies of spare parts manufactured according to the same Russian standards as the originals. Therefore, the dissimilar welds of original Russian steel 08Ch18N10T and substitutive 1.4541 were made and analyzed to consider the possibility of original steel replacement during the repairs. Two different filler wires were applied. The welds were (…)
This paper presents an innovative accelerated subspace iteration method tailored for simulating varying eigenpairs of thin-walled workpieces. The proposed approach significantly boosts computational efficiency by selecting optimal start iteration vectors for a given cutter location. The optimal start iteration vectors are generated based on the previously calculated eigenvectors from the preceding cutte (…)
In this article, the effects of selected quantities on the thickness of a fouling layer that is formed on the internal surface of the pipes of natural gas (NG) coolers are discussed. Models created by applying an analytical method, a dimensional analysis, and a multiple linear regression were compared. The most complex model was the analytical model with a total of 16 relevant physical quantities. From (…)
Among alternative energy sources, wind energy is one of the fastest growing sectors. However, conventional wind turbines have their limits, especially when it comes to their application in more densely populated areas and in areas with a long-term lower average wind speed. In the future, the Archimedes wind turbine could contribute to an even more significant use of the potential of wind energy. In the (…)
Recently, the role of hydrogen technology has become more important in decarbonizing society and achieving carbon neutrality goals. The most important sector where it is possible to implement hydrogen technologies to achieve carbon neutrality is the automotive industry. For hydrogen technologies in the field of transport to be able to compete with conventional motor vehicles, research in several areas i (…)
The aim of the study is to investigate the effect of point reduction on the dimensions of a part produced by two different additive technologies, Stereolithography (SLA) and Fused Deposition Modelling (FDM). Also, the effect of polygonization methods on the number of points and file size. For the purpose of the experiment, a part was fabricated which was made up of geometric elements, which served to in (…)
When parts are machined, especially on heavy machine tools, an accurate description of the rotations around the geometric axes is required. The work adds the concept of rotation around the machine and the workpiece axes. Both types of rotation in mechanics are related to internal and external rotations, which we describe in detail. We show how both types convert to each other and how conversion formulas (…)
The Male and Cockroft ring compression test stands as one of the methods utilized to determine the coefficient of friction in forming processes. This approach eliminates the need for force measurement. This study presents the outcomes of the Male and Cockroft ring compression test conducted on Hardox 450 material at varying strain rates, conducted without lubricant. The experiments were carried out usin (…)
SECURE 400 steel is used for basic ballistic protection of armoured vehicle chassis against the pressure energy of exploding mines, IEDs and grenades. It is a low-alloy high-strength steel with a manufacturer's declared hardness of 380 to 430 HB, which is characterized by a good combination of high strength and toughness. As standard, this steel is processed by quenching followed by tempering, but new p (…)
The article presents the results of a study of theoretical, methodological and practical aspects of marketing activities at industrial enterprises, systematized in the form of three functional models of marketing activities implemented at industrial enterprises, taking into account the specific features of changes in marketing activities depending on the functional marketing model implemented at the ent (…)
Dual-phase (DP) steel plates are characterized by very good absorption capacity, so they are used in the automotive industry for body deformation zone parts. They are attached to the frame of the car-body by welding. Laser welding of dual-phase steels is gaining increasing importance in the automotive industry. In the present paper, the possibility of predicting the strength and deformation characterist (…)
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