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

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 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 presents the results of research aimed at determining surface wettability. The research was focused on microtexturing by low-energy laser irradiation of the surface of molded parts using innovative engraved surface treatment methods (LBT and EBT) to ensure a smooth distribution of the separation agent on the surface of high-pressure Al castings. The basic material was Uddeholm Dievar, which is used to make molds. PVD coatings were applied to the base material. The effect of laser texturing surfaces on the contact angle size was determined. Contact angle was evaluated on the base material, on PVD coatings without surface treatment and with the use of two types of separating agents.

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 focuses on the degradation of molds that are used for the technology of high-pressure casting of Al and its alloys. The method of high-pressure casting of aluminum products is one of the widely used production methods, which at the same time meets the requirements for precision and productivity in the production of cars and various mechanical parts. In the high-pressure casting process, the molds are exposed to various thermal and mechanical loads, where the molds and their shaped parts are degraded. The paper presents the results of research focused on the use of duplex PVD coatings to increase the life of shaped parts of molds for high-pressure casting of Al and its alloys.