A progressive type of tungsten-doped DLC coating was applied to a quenched and tempered 100Cr6 steel with the aim to improve the wear and corrosion properties in simulated seawater conditions and to compare the performance to conventional DLC coating. Tungsten doping caused a shift of the corrosion potential (E_corr) to a lower negative value of −172 mV, while the conventional DLC exhibited an E_corr of −477 mV. In dry conditions, the W-DLC coefficient of friction is slightly higher than that of the conventional DLC (0.187 for the W-DLC vs. 0.137 for the DLC), but in cases of a saltwater environment, this difference becomes almost negligible (0.105 for the W-DLC vs. 0.076 for the DLC). The conventional DLC coating also started to show marks of deterioration when exposed to a combination of wear in a corrosive environment, while the W-DLC layer still maintained its integrity.

The article deals with a reduction of friction coefficient of bearing steel 100Cr6. Reduction of friction was achieved by means of a CarbonX DLC coating. The coating exhibited excellent friction and mechanical properties. This coating was applied to samples made of 100Cr6 bearing steel. The friction results of the CarbonX coating were compared to the friction results of the 100Cr6 bearing steel. Reducing the friction of 100Cr6 bearing steel resulted in reduced wear and increase lifetime. The friction process of the samples will take place in an environment without lubrication. The aim of the article is to verify the behaviour of the DLC coating without the presence of lubricant in the friction node. The achieved results are to be interpreted in the conclusion of article.

The tribological properties of the nitride layer applied to the low-alloyed steel were investigated in this research. Experimental work included determination if the chemical composition, wear resistance, Rockwell, Vickers and nano-indentation tests, both of the substrate material – the low-alloyed steel and the deposited nitride layer. From the results obtained in those experiments authors concluded that applying the nitride layer does not significantly improve the tribological properties of the tested lowalloyed steel samples, thus this process is not recommended for achieving that purpose.

Influence of shot peening on the wear behaviour of medium carbon, C55 steel was experimentally verified. Experimental work included determination of the chemical composition, heat treatment, microstructure evaluation, mechanical properties measurement, shot peening treatment, the magnitude of the compressive residual stresses was evaluated, roughness profiles measurement and finally the friction tests. The results evidence the significant role played by the applied shot peening on wear behaviour of medium carbon steel. An important effect of surface roughness has been demonstrated. The coefficient of friction after shot peening compared to ground surface increased, 1.44 – 1.85 times.

This study investigates the properties of diamond-like carbon (DLC) coatings deposited onto a Ti6Al4V titanium alloy using plasma-assisted chemical vapor deposition (PACVD). The research encompasses adhesion tests, hardness, surface characterization, as well as corrosion and tribological evaluations. Artificial saliva was employed as both the lubricating and corrosive medium. Microscopic examination revealed a uniform coating with a thickness of about 3.2 µm. Scratch test results indicated that the deposited DLC coating exhibited superior adhesion, lower frictional resistance, and reduced wear compared to the titanium alloy. The coating deposition increased the hardness of the Ti6Al4V alloy by about 75%. Friction coefficients, measured under dry and lubricated conditions, were approximately 80% lower for the DLC-coated samples. Corrosion studies revealed that both the coated and uncoated surfaces demonstrated typical passive behavior and high corrosion resistance in artificial saliva. For DLC coatings, the corrosion current density and the corrosion rate were reduced by 85%. Microscopic observations of wear tracks following tribological and scratch tests confirmed the inferior wear and scratch resistance of the titanium alloy relative to the DLC coating. Under both dry and lubricated conditions (with artificial saliva), the volumetric wear rate of the titanium alloy was over 90% higher than for the DLC coating.

The presented article familiarizes the reader with optimizing the workplaces of ultrasonic welding machines. The essential part of the article deals with prototypes, the construction of which does not meet the requirements for production, economy, and functionality. The experimental analysis runs pointed out shortcomings and inaccuracies. The developer’s team used one of the well-known optimization and design methods to solve this issue. It is the TRIZ method (Creating and solving creative assignments). The mentioned method combines two powerful tools into one whole. Specifically, it is the Function and Cost Analysis (FNA) and the algorithm for solving creative assignments (ARIZ). The manuscript describes the use of the method for a more straightforward solution to problematic parts of the structure. The result of the optimization process is a new, improved structure whose properties were confirmed in terms of stiffness by simulation in the ANSYS Workbench program. The applications of optimized parts will also be used in other similar devices. The research will follow up with the design of a new series of ultrasonic welding machines in the future.