BALTTRIB, Proceedings of International Conference

TRIBOLOGICAL EVALUATION OF PALM OIL-BASED TRIMETHYLOLPROPANE (TMP) LUBRICANT ENHANCED WITH GRAPHENE OXIDE FOR ENGINE OIL APPLICATIONS

2025-12-30T13:59:28+02:00

Palm oil's long molecular fatty acid chains make it a promising candidate for lubricants due to its potential to reduce wear and friction. However, its thin fluid film may sometimes fail to protect contact surfaces. To solve this, an effective additive is required. This study used trimethylolpropane (TMP) as the base lubricant and graphene oxide (GO) as a nano-based additive. The combination's performance was evaluated using a Four-ball tribotester, measuring friction coefficient, wear scar, and surface roughness under various conditions, and compared with synthetic and mineral oils. While the TMP +0.5wt% mixture had a slightly higher friction coefficient than pure TMP, it outperformed both mineral and synthetic oils in friction reduction. Additionally, the TMP+0.5wt% formulation showed significant improvements in surface roughness and wear scar diameter, indicating enhanced surface protection and wear resistance with the inclusion of graphene oxide.

EFFECT OF HEAT TREATMENT ON THE ABRASIVE WEAR OF WELDED JOINTS OF MARTENSITIC STEEL WITH BORON

2025-12-30T14:15:49+02:00

The welding of martensitic steels in any case results in a reduction of mechanical properties and thus resistance to abrasive wear, both in the zone of the weld material and the broad heat-affected zone. This is due to the maximum strength of commercially available welding consumables not exceeding the tensile strength R_m value of 1000 MPa, which for steels with a claimed hardness of 500 HBW and a strength of min. 1500 MPa, results in a reduction of mechanical properties in the zone of the weld material by a minimum of 40% compared to the base material. To address this issue, the authors decided to subject welded joints of selected high-strength steel to comprehensive heat treatment procedures aimed at restoring the martensitic microstructure in the weld zone. The study demonstrated that the hardness of the weld material could be increased from 213 HBW in the as-welded state to 357 HBW after heat treatment. This improvement led to a corresponding increase in the relative abrasive wear resistance coefficient k_b, rising from 0.87 to 0.97, bringing it closer to that of the base material (k_b = 1.00).

CAVITATION EROSION OF 3D PRINTED MARAGING STEEL

2025-12-30T14:25:52+02:00

We are witnessing the expansion of the application of metal machine parts and elements obtained using some of the additive manufacturing technologies. However, there are still not many publications on the surface load-carrying capacity of 3D-printed parts, especially worn by cavitation erosion. If cavitation occurs in the fluid that is in contact with the surfaces of machine parts, erosive wear may occur due to high-cycle fatigue of local micro volumes. The result is a loss of material mass and a change in the geometry of the surfaces. In this way, the functionality of the parts, operational ability, load-carrying capacity, service life, and reliability were reduced. The degree of surface damage of machine parts exposed to cavitation depends on the chemical composition, microstructure, and mechanical and anti-corrosion properties of the material. This paper presents the results of testing the resistance to cavitation of metal samples produced on a 3D printer by laser sintering of high-quality steel powder of maraging steel MS1.

IMPROVEMENT OF PERFORMANCE PROPERTIES OF TITANIUM ALLOYS BY APPLYING PEO COATINGS

2025-12-30T14:36:37+02:00

Titanium and its alloys are widely used in various industries due to their unique properties - low density, high thermal stability and specific strength, high corrosion resistance, good biocompatibility. However, along with high physical and mechanical properties, titanium alloys have low wear resistance. In order to improve the properties of titanium and its alloys, plasma electrolytic oxidation (PEO) of their surface is considered as a reliable, simple and environmentally friendly method that allows to improve the performance characteristics of titanium and its alloys. The influence of the component composition of electrolytes and process modes, which affect the microstructure and formation of PEO films, was analyzed. It is shown that PEO coating is promising and can provide optimal tribological and corrosion properties of titanium and its alloys.

ENHANCEMENT OF WEAR RESISTANCE OF Ti6Al4V TITANIUM ALLOY BY SURFACE MODIFICATION

2025-12-30T14:57:59+02:00

The effect of surface modification (thermal oxidation and gas nitriding) on phase-structural state and wear resistance of Ti6Al4V titanium alloy was investigated. The wear resistance was evaluated under dry friction conditions with various loads (10 to 25 N). The friction and wear experiments demonstrated that under various loads, the wear of the surface-treated Ti6Al4V alloy decreased by 5–37% (for oxidation) and 28–47% (for gas nitriding) compared to that of the untreated one. It should be noted that the greater the load during dry sliding friction, the greater the effectiveness of the proposed surface treatments. The best wear resistance of titanium was provided by gas nitriding due to the formation of a surface compound (TiN+Ti₂N) layer with high hardness. To conclude, our findings indicate that surface modification is an effective approach to improving the wear performance of Ti6Al4V alloy.

ADHESIVE WEAR OF TOOL STEELS WITH FUNCTIONAL COATINGS

2025-12-31T10:02:27+02:00

When processing metals by cutting, there are several materials prone to adhesion. This phenomenon leads to a change in the geometry of the cutter, cutting force and surface quality, technological dimensions of the detail. In this work, experimental studies of the processes of dry friction of tool steels with coatings were carried out to evaluate the effectiveness of reducing the process of adhesive bonding of materials. It was established that the nature of formation, destruction and size of adhesive areas depends on the chemical composition of the material and modes of friction. High-strength chromium-manganese steels are most prone to adhesion and microburring. It is shown that increasing the cutting speed cannot always be used to prevent adhesion. Along with this, adhesion reduction can be achieved using single-layer and multi-layer coatings with a defect-free structure and moderate friction modes. It has been experimentally proven that electrolytic single-layer nickel and chromium coatings contribute to the formation of growth on the studied materials and this phenomenon does not depend on friction modes. At the same time, electrochemical coatings, which have a defect-free structure, are almost not amenable to adhesion.

INVESTIGATION OF MECHANOCHROMIC AND TRIBOLOGICAL PROPERTIES OF A NOVEL THERMALLY ACTIVATED DELAYED FLUORESCENCE CARBAZOLE DERIVATIVE FOR LIGHT-EMITTING ELECTROCHEMICAL CELL APPLICATION

2025-12-31T09:54:50+02:00

This study investigates the design and synthesis of fish-shaped structures based on carbazole derivative for applications in light-emitting electrochemical cells (LEECs). A thermally activated delayed fluorescence (TADF) carbazole derivative was synthesized as an emitter in the active layer using a coupling reaction technique. [Ir(buoppy)₂(dmapzpy)]PF₆ was employed as a promising host, resulting in high-performance LEECs with enhanced brightness of 4952 cd.m^-2 and an external quantum efficiency (EQE) of 4.09%. The synthesized dye exhibited a lower singlet-triplet energy splitting (ΔE_ST) value of 0.06 eV compared to other reported counterparts, with reverse intersystem crossing (RISC) dominating its photophysical behavior. The crystalline dye demonstrated mechanochromic behavior, as its photoluminescence (PL) spectrum red-shifted upon mechanical stimulation. This mechanochromic behavior was also observed in the fabricated LEECs, and the tribological properties were further investigated.

FINITE ELEMENT MODELING OF STRESS BEHAVIOR IN COLD FORGING PROCESSES UTILIZING PALM KERNEL OIL AS A BIO-LUBRICANT

2025-12-30T11:14:24+02:00

Mineral oils have traditionally been used in most metal-forming lubricants. Vegetable oils, such as palm kernel oil (PKO), may serve as a non-toxic and biodegradable alternative. This study investigates the potential of PKO as a bio-lubricant in metal forming processes using the finite element method. The research focuses on stress-strain characteristics of workpieces lubricated with PKO to evaluate its effectiveness as an environmentally friendly option. The finite element model accurately simulates the mechanical behaviour, highlighting PKO's role in reducing friction, enhancing formability, and minimizing tool wear. A comparison with conventional metal forming oils, using aluminium (AA1100) as a specimen, demonstrates the significant advantages of PKO in promoting process efficiency and sustainability. These findings emphasize the relationship between friction and stress, particularly in low-deformation regions like the dead meal zone.

COMPARATIVE EVALUATION OF CLEANING METHODS FOR AVIATION MINIATURE ROLLING BEARINGS

2025-12-30T11:42:32+02:00

The results of the granulometric and chemical composition of the removed contaminant particles from ball bearings by the non-separable pulse-magnetic turbulent and ultrasonic methods are presented. The removed contaminants from aircraft ball bearings of two standard sizes 24×12×6 mm and 28×12×7 mm, were studied using a laser scanning microscope and a scanning electron microscope REM-106I. The analysis of the microparticles from the rolling path of the ball bearings showed contaminants such as non-metallic particles, steel chips and dust, copper alloy chips, organic fibres, and lubricant residues. The particle size analysis showed that particles of less than 1 micron to 50 microns were removed from the rolling path. Comparative experiments have shown that the magnetic turbulence method allows for more efficient removal of contaminant particles much larger than 1–2 microns. The ultrasonic method showed the highest efficiency on the smallest contaminants.

IMPROVEMENT OF CAR TIRES TRIBOLOGICAL PROPERTIES IN MOTION

2025-12-31T09:01:23+02:00

Modern trends in the development of car tires, in addition to the automation of the operation process, are also aimed at increasing their operational characteristics, one of the criteria that determines the state of tire behavior is tribological properties [1]. The indicated properties of the tire directly depend on its service life, fuel efficiency, and the comfort of the car, as well as traffic safety [2]. Therefore, the study of tribological properties of tires with the aim of further improving the efficiency of tires as a whole is currently a rather urgent task. The state of dynamic interaction in the "wheel-tire-road" system was studied, namely the car wheel rolling process, when its tire is subjected to deformation, which contributes to the creation of a moment of resistance to the rolling of the wheel and the actual adhesion of the wheel to the road. As a result of the research, ways to improve the tribological properties of car tires during movement are proposed.

INCREASING THE WEAR RESISTANCE OF INTERNAL COMBUSTION ENGINE CYLINDER LINERS BY APPLYING ANTIFRICTION COATINGS

2025-12-30T13:31:44+02:00

Since the service life of internal combustion engines depends on the durability of cylinder-piston group parts, the development of effective technologies for the restoration of cylinder liners that increase their wear resistance and durability is of particular importance. The effectiveness of the combination of finishing antifriction non-abrasive treatment and the method of cold plastic deformation – deforming broaching in the restoration of cylinder liners has been proposed and proven. The original design of a modeling device for testing the wear resistance of the cylinder liner working surface, including a counterbody that simulates a set of piston rings simultaneously interacting with the working surface of the liner, was developed. The use of the proposed accelerated testing methodology significantly reduces the time required to conduct wear tests. The technology for restoring cylinder liners using finishing antifriction non-abrasive treatment and deforming broaching reduces wear on the working surface compared to traditional processing. The technical solutions applied in this work increase the wear resistance of the machined parts.

NITRIDING OF LONG-DIMENSION HOLES IN CYCLIC-SWITCHED DISCHARGE

2025-12-30T13:47:45+02:00

The paper presents the results of the study of the surface microhardness and wear resistance of steel 45 nitrided in a hydrogen-free environment in a glow discharge with the gas discharge chamber powered by a cyclically switched discharge. The experiments were carried out on a model that is a hollow cylinder with holes drilled at a certain distance from the ends, into which samples of steel 45 were inserted with a certain tension. Thus, the ends of the samples outside and inside the cylinder were nitrided under practically the same technological conditions. Two options for nitriding the inner surfaces of the holes in a cyclically switched discharge were considered: a through hole (the ends of the cylinder are open) and a blind hole (one end of the cylinder is closed with a lid). For comparison, the results of strengthening the inner surfaces of the holes by nitriding with a constant current supply to the gas discharge chamber are given. The results obtained show the efficiency of nitriding of long-length through.