In this study, the wear performance of spheroidal graphite cast iron subjected to plasma nitriding at different temperatures and treatment durations was investigated. The plasma nitriding parameters were optimized by response surface methodology (RSM) due to the output performance. Plasma nitriding was applied at three different temperatures (400, 450, 500 °C) and three different heat treatment durations (0.5, 2, 4 h). Wear tests were performed by ball-on-disk method for 60 minutes and for three different wear loads (10, 20, 30 N). The specimens were investigated for hardness, microstructure and wear performance. The RSM model was then created by using the wear resistance features. Plasma nitriding showed better wear performance than the untreated specimen for all treatment conditions. Hardness, nitrided layer thickness and wear performance remarkably improved with increasing temperature and process duration. The parameter that affects volume loss the most is wear load with 70.66% according to RSM modeling results. The most effective parameter in the wear rate change was found to be treatment duration at 42.85%. The model was able to predict the results with an error of 2.11% for volume loss and 9.14% for wear rate. The prediction results are very close to the experimental results. This clearly shows that the model can be used to determine the plasma nitriding parameters.

In this study, the AISI 304 steel specimens were boronized with nanoboron of the size of 10–50 nm and commercial Ekabor 3 powders (<1400 μm) at 950 °C to 1000 °C for 2 h and 4 h. Boronized steel specimens were characterized via SEM, microhardness and XRD analyses. Abrasive wear behavior of the specimens, boronized at different temperatures and treatment durations, were examined. The fixed ball micro-abrasion tests were carried out using the abrasive slurry, prepared with different SiC powder particle sizes on the boronized specimens at different rotational speeds. The specimens boronized with nanoboron powders exhibited a higher hardness and abrasive wear resistance than the samples boronized with the Ekabor 3 powders.

In this study, the synthesis of hydrothermal carbon (HTC) lubricant and its usability as a lubricant under hot industrial conditions were investigated. In this context, the characterization of HTC produced from organic sources at low cost and in a short time was performed, and its tribological performance was analysed in detail. HTC produced by the hydrothermal carbonization method was characterized through SEM images and EDS analysis. To determine the effect of HTC on friction at different temperatures, HTC was subjected to a pin-on-disc wear test with AA5754 material. The effect of various lubricants, temperatures, blank holder pressure, and forming speed parameters on the forming force for the analysis of the tribological effect of HTC on deep drawing processes were statistically analysed. The performance of HTC was compared with Teflon, fullerenes, graphene, and carbon nanotube (CNT) materials. According to the results obtained from wear tests, the lowest friction coefficient value was achieved in the presence of fullerenes as the lubricant, and as the temperature increased, the friction coefficient decreased. It was observed that HTC exhibited lower performance in the wear test compared to fullerenes due to oxidation. When the effect of deep drawing parameters on the forming force was analysed, it was concluded that the most effective parameters were temperature (72.32%) and lubricant (20.89%). According to the S/N analysis results, the minimum forming force was obtained under the conditions of solid Teflon lubricant, 250 °C temperature, 15-bar blank holder pressure, and 2 mm/s forming speed. The tribological performance difference between HTC and Teflon is at the 1% level. The results demonstrate the potential industrial usability of HTC as a lubricant.

In this study, the effect of laser surface texturing (LST) applied to NiTi Shape Memory Alloy (SMA) on the dry sliding wear behavior of the material was investigated. After polishing and cleaning the material surface, a pitted surface texturing process was performed using a femtosecond laser under atmospheric conditions. After the surface texturing process, dry sliding wear tests were performed at room temperature. When the wear behavior of the laser-applied and non-laser-applied test samples was evaluated comparatively, it was determined that the coefficient of friction (COF) of the laser-applied samples under 1N load was approximately 17% lower. It was determined that the decrease in the COF value decreased with increasing load. However, the wear amount of the LSD-applied NiTi SMA was higher than the untreated sample. It was evaluated that this situation was due to thermal softening that occurred depending on the ablation geometry and dimensions.