Wear of tillage tools by hard soil particles is a serious concern in the industry since wear is the primary factor that defines an engaging tool's lifespan, stability, and reliability. Many studies have primarily focused on experimental methods to better understand the impact of various parameters on tool wear during tilling operations. Hence, this project focuses on both continuum damage mechanics (CDM) modesl based on thermodynamics for predicting the wear coefficient in tillage tools and experimental validation. The wear process is modeled as sand particle scratching at a prescribed speed and load on the surface of a tillage tool with different hardness, such as heat treated, chromium coated, heat-treated chromium coated, and samples without any treatment. Tillage tool wear is taken as the response (output) variable measured during contact, while operation parameters speed, load, and hardness are taken as input parameters. For C45E4 samples, tests are carried out with a dry sand/rubber wheel abrasion tester, and material loss from the tool surface during scratching is evaluated using the weight loss concept. The design of experiments technique is developed for three factors at four levels. The comparison shows an acceptable agreement in the experimental data and predicted results, which states an error of <20 %. The results also show that heat-treated samples with chromium coating have more abrasive resistance with respect to other samples.

The paper provides and comments on the results of studies of the effect of sandstone-based abrasives and quartz sand alone on the wear of martensitic surfaces of wear-resistant steels. The wear process was examined on a ring-on-ring test rig seeking to determine the mass decrement parameter which characterised wear. In addition, SEM microscopy, optical profilometry and XRF analysis were used to analyse the abrasives used and damaged surfaces. The tests were conducted for three sandstone varieties, Carboniferous, Permian, and Cretaceous, and they made it possible to determine that the most intense process of deterioration of wear-resistant steels took place in the presence of quartz sand grain, while less intense wear was observed in the case of sandstone-based abrasives. The mass decrement values established in the presence of the sandstones in question did not differ significantly between individual sandstone varieties. Based on a surface damage analysis, the basic damage mechanism was found to be micro-scratching; however, with regard to the sandstones examined, it was also determined that individual grains could be pressed into surface irregularities and that films of soft hematite cement developed in the Permian sandstone and that inclusions of carbonaceous matter were formed in the Carboniferous sandstone. With reference to the wear process observations, a wear model was described for the surface of the steels examined in the presence of sandstone-based abrasives. This model presents the possibility of capturing wear products by unstable binder layers and changing the form of wear from three-body to two-body.

In this work, a tribological approach was used to distinguish the synergistic effects of mechanical removal and chemical removal (i.e. dissolution) of a layer of representative food soil from a solid surface, using a tribometer, Mini Traction Machine (MTM). Gravimetric and wear measurements of the soil were used to calculate the cleaning rates of burnt tomato puree on a stainless-steel disc, and the corresponding frictional characteristics offers insight of the mechanical removal. The cleaning due to soil dissolution (chemical removal) was quantified by UV-Vis measurements. The overall cleaning rates of food soil featured a linear reduction in mass over time, with a scaled removal rate k = 0.0046 s-1 (5 N applied force and 100 mm s-1 relative velocity), for most cases studied. It was observed that the cleaning rate can be improved with an increasing mechanical load or speed (50% from 1 to 2.5 N and 13% from 50 to 100 mm s-1), but is independent of the initial mass. UV-Vis measurements show that by increasing the load or speed the removal of chunks of burnt tomato puree was enhanced more than removal attributed to dissolution. Similar values of cleaning rates for most experimental parameters were extracted from both the gravimetric and wear measurements. Adhesion and cohesion measurements of the burnt tomato puree were conducted with a micromanipulator. It was found that adhesion forces are higher than cohesion for short soaking times, but for longer times the adhesion forces became weaker and with the additional shear rate in the MTM cleaning experiment, adhesion failure was observed in many cases by the end of the experiment. Indentation measurements showed the change in mechanical properties of the food foulant with a few minutes of soaking in water.

Lunar exploration has emerged as an exciting area for the scientific community and aerospace industries. However, the lunar environment presents daunting challenges, including extreme temperatures, high vacuum conditions, and sharp abrasive lunar regolith. Past explorations have demonstrated that the lunar regolith is particularly difficult to contend with, as its abrasive and erosive nature damages equipment and rover due to wear. Herein, an assessment is made on the tribological performance of key structural and optical components used in space vehicles, rovers, and on-field equipment operating in the lunar regolith environment. The evolution of erosive and abrasive test equipment, its benefits, limitations, and simulant characteristics, such as particle morphology and size, are examined on different materials' impact and abrasive wear. Abrasive and erosive wear mechanisms are elucidated based on regolith particle impact velocity, impact angle (erosion), regolith morphology, and particle size (abrasion). The lack of research on how temperature affects the wear behavior of materials under lunar regolith represents a significant gap in current knowledge. By identifying these gaps and providing alternative pathways, this critique can guide researchers in developing effective dust mitigation strategies and advancing the testing and analysis of prospective space materials. (c) 2023 COSPAR. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).