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

This paper deals with the possibility of renovating exterior plastic automotive components using adhesive bonding technology. The research focuses on the evaluation of the shear strength of adhesive joints formed using adhesive systems commonly applied in automotive repair practice. The experimental investigation was carried out using selected adhesives, and the shear strength of the bonded joints was evaluated. To simulate real operating conditions of vehicles, accelerated laboratory tests were performed in which the bonded joints were exposed to various degradation environments. Subsequently, changes in the shear strength of the adhesive joints were evaluated after their exposure to these conditions. The study also examined the influence of road de-icing agents commonly used in winter road maintenance on the quality and integrity of the adhesive joints. Based on the analysis of fracture surfaces, the failure mechanisms of the joints were identified and classified as adhesive or cohesive failure. The obtained results provide a basis for assessing the applicability of adhesive bonding technology for the renovation of exterior plastic automotive components and contribute to the optimization of repair procedures used in automotive maintenance practice.

Tribological properties of functional surfaces are a key factor influencing the durability, reliability and efficiency of mechanical systems. One of the progressive approaches to surface modification is laser surface microtexturing, which allows for the precise creation of controlled microstructures capable of modifying contact conditions and lubricant retention at tribological interfaces. This article focuses on the application of laser-induced surface microtexturing to improve the tribological performance of hard nanocomposite coatings nACRo³ and nACRo⁴. The experimental part of the research is dedicated to the preparation of microtextures on the substrate surface using a pulsed laser system, followed by the deposition of nanocomposite coatings nACRo³ and nACRo⁴. The created microstructures are characterized in terms of their geometry, distribution and influence on the contact properties of the coated surfaces. The wettability of the microtextured surfaces was evaluated based on the measurement of the contact angle. Optimizing surface microtexture is an effective way to increase wettability and potentially improve lubrication conditions during technological processes of forming or tribological loading of materials.
Keywords: laser surface texturing, tribology, nanocomposite coating, wettability, contact angle, PVD coating, tool steel, die casting

Article presents the results of research aimed at determining the quality of the weld layers produced during the renovation of the surfaces of molds intended for injection molding of aluminum alloys. Plasma arc transfer (PTA) technology was used. Medium alloy steel X38CrMoV5-1 (H11) was used as the mold material. Three types of additives in powder form were used to create functional layers: two iron-based types with the designation HSS 23 and HSS 30 and one nickel-based type with the designation DEW Nibasit 625-P. The quality of the layers was assessed using non-destructive and destructive tests. The surface integrity of the layers was assessed using visual and capillary tests. Chemical composition of the elements was determined by energy-dispersive X-ray spectroscopy (EDX) analysis using a SEM microscope and the hardness of individual layers was evaluated also. Since molds are subject to significant frictional wear during operation, friction coefficients

The paper presents the results of a research focused on the application of laser surfacing of functional surfaces using an additve material in the form of a wire. Cladding is made in a single layer using a robot. The quality of the cladding layer was evaluated by ultrasonic inspection. Possible occurrence of internal defects was assessed. Macrostructures and microstructures were analyzed on metallographic sections using light microscopy. Influence of the used additive material and the cladding parameters on the microhardness behaviour in the individual parts of the test specimens was also evaluated.

Paper presents experimental work focused on the application of the separating agent-lubricant SafetyLube 7815 on the surface of the tested samples: ground surface; polished surface; surface of the samples textured by laser in the mode stochastic texture mode. Duplex PVD coatings nACRo4, AlXN3 and AlTiN G were deposited on the surface. The aim of the experimental work was to approximate the breakin conditions of a new or renovated mould part for high pressure casting of aluminium alloys. The release agent-lubricant SafetyLube 7815 was applied to the surface of the specimens by dispersive spraying. The method of measuring the contact contact angle measurement, the influence of the finishing operations of the mould part surface on the surface wettability by contact angle measurement.

This paper presents the results of an investigation aimed at evaluating the geometric and material characteristics of welds, such as dimensions, shape, pores, cracks and other imperfections. An automated weld inspection workstation has been designed which includes suitable sensors, equipment and software solutions for data acquisition and processing. Tests were performed on selected welds to determine the material superheat and weld quality.

The paper presents the results of research focused on the application of innovative procedures for surface topography modification. The experimental work was aimed at adjusting the microgeometry and surface topography of new and renovated shaped parts of molds for casting aluminium alloys under high pressure. In the phase of experimental verification of suitable surface topography, a group of samples from Dievar material was prepared. A multilayer nanostructured PVD coating of the 4th generation duplex nACRo4 was deposited on part of the experimental samples. The surface of the samples was ground and polished. The microgeometry of the surface of the samples was modified by low-energy laser radiation – microtexturing. The maximum interval was chosen to create a stochastic texture, also called a random texture crater distance up to 200 μm. The aim of this surface treatment was to analyze the adhesion effect of commercially used ones of lubricants in the technology of treatment of shaped parts of molds when casting aluminium alloys under high pressure on machines with a cold filling chamber. In the run-in of the mold, after the first cycles of spraying with a separating agent, a compact layer was created to increase the technological life of the shaped parts of the molds.

The paper presents the results of research aimed at determining the quality of renovation layers using laser technology. In order to repair and renovate shaped parts of molds for casting aluminum alloys under high pressure, samples of experimental welds were prepared on the base material quality 1.2343 (Dievar). The renovation layers were created using additional materials Dievar, UTP A 7002 and NIFIL NiCu7 res. NiCu7 with Dievar combination. The microstructures on the cross-sections of the deposits were checked using the light microscopy technique. The technique of scanning electron microscopy and semi-quantitative EDX microanalyses were analyzed distribution of alloys in deposits. The microhardness of the deposits was determined.

The paper presents the results of research aimed at determining selected tribological properties of PVD nanocoatings. PVD nanocoating of the 4th generation duplex nACRo4 was applied to the surface of shaped parts of molds and cores for high-pressure aluminium casting. The surfaces were laser textured with a random texture. The tribological properties of the coating were determined by measuring the friction coefficient using the Pin on Disc method at a temperature of 300 °C. Confocal microscopy was used to determine the parameters of the microgeometry of surfaces with random texture topography. The aim of this surface treatment was to analyse the adhesion effect of commercially used ones of lubricants in the technology of treatment of shaped parts of molds when casting aluminium alloys under high pressure on machines with a cold filling chamber. By checking the integrity of textured surfaces with deposited with the duplex PVD coating of the 4th generation nACRo4, no damage to the integrity of the deposited material was detected PVD coating. Elements forming the PVD coating were detected on the surface by semiquantitative EDX microanalysis.

CMT technology provides significant advantages, such as reduced deformation due to high temperatures, high welding speed and a significant reduction in spatter compared to the MIG/MAG method. The experimental work was focused on verifying the possibility of renovating the surfaces of molds for high-pressure aluminum casting using CMT technology. A mold wear analysis was performed and a method of restoring functional surfaces was proposed. Two types of additive materials were used – Thermanit 625 and Thermanit X. The quality of the layers was evaluated by SEM, EDX microanalysis and the coefficients of friction of the layers were determined by the Ball-ondisc method. The renovation layers were also subjected to an immersion test in Al alloy at 680 °C.

The paper focuses on the evaluation of the quality of fillet welds produced robotically by the method of impulse synergic welding MAG. This welding technology is used in the automotive industry in the production of rear seat backs for passenger cars. In the process of automated production, the speed of the process, accuracy, and quality of the made joints are important. Several factors affect the accuracy and quality of welded joints. The paper presents the results of research where the influence of filleting of fillet welds on their quality was confirmed. Visual and capillary methods were used to determine the quality of welds, metallographic analysis for evaluation depth of weld root penetration, strength properties of welds were evaluated by static tensile test. Statistical ANOVA methods were used to process the obtained values. Experimental work confirmed that the depth of welding of the weld root into the base material has the greatest influence on the final quality of fillet welds. It is this parameter that results in the elimination of the weld and thus the entire produ ct.

The paper presents the results of quality evaluation of weldments produced by a mutual combination of different steel grades. Weld joints were made using GMAW technology (method -135 ISO 4063). The type of welding parameters used for the quality of welded joints was monitored. The quality of welded joints was assessed using non-destructive tests. In non-destructive tests, the Visual test according to EN ISO 17637, the Penetration test with colour indication according to EN ISO 22476-12 was used to identify surface defects. The presence of internal errors was assessed by a radiation test according to EN ISO 17636-1. Within the destructive tests, the quality of the welds was assessed by a tensile test according to EN ISO 6892-1, by the test of brittleness of welds according to EN ISO 5173, the course of hardness according to EN ISO 6507-1 was determined on transverse cuts. The bending impact test according to EN ISO 9016 will determine the toughness of the weld metal and heat-affected areas. Metallographic analysis of welds according to EN ISO 17639 was performed on transverse metallographic sections using light microscopy. Based on the performed experiments, recommendations were set, or proposed changes in the welding procedures of the given steel grades.