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

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

Wear, is one of the most important failure type which reduces the service lifetime and increases the maintenance cost of machines. In addition, wear is directly related with surface properties and friction characteristics. So, researchers focus on various surface treatments to reduce the wear and its cost. Plasma nitriding is one of surface treatment which forms a few hundred micron diffusion zone and a surface inter-metallic phases with moderate surface hardness. PVD coating is another method which ensures ultra-hard and a few micron surface layers. In the present study, AISI H13 hot work tool steel substrate was surface treated with various methods, such as plasma nitriding, PVD coating and duplex treatment. Effects of the treatments on the surface roughness, hardness were investigated. Additionally, microstructural analysis was performed to present the effect of treatments on the surface microstructures. Furthermore, friction characteristics were investigated using ball on disk testing machine and wear tracks were discussed using optical microscopy.