Improving the fracture toughness of agricultural soil-engaging components can mitigate the detrimental effects of hard particles in the soil while maintaining the wear resistance of the components, thereby improving the service performance. The wear resistance of the parts can be improved by surface treatment, but the surface toughness after treatment still needs to be further improved. In this study, WC10Co4Cr@YSZ (Yttria Stabilized Zirconia) core-shell structured composite powder was synthesized by modifying commercial WC10Co4Cr powder using the sol-gel method, and WC10Co4Cr coatings were prepared using the powders before and after modification. The microstructure of the powder and coatings were characterized. The mechanical properties and wear resistance of the coatings were evaluated through microhardness, nanoindentation, and friction testing. The hardness of the YSZ-modified composite coating was comparable to that of the unmodified coating, yet it exhibited lower porosity and twice the fracture toughness. Wear test results indicated that the coating's wear loss was greatly reduced compared with the substrate. In addition, the wear rate of the YSZ-modified coating was 71.11 % lower than the unmodified coating, demonstrating its exceptional wear resistance. The findings show that incorporation of YSZ into the coating system further enhanced wear resistance. The strengthening mechanisms resulting from the YSZ inclusion include the pinning effect, which controls the size and distribution of the WC grains, the shell structure that prevents overheating, and the improved fracture toughness of the coating. This work provides a new way to extend the service time of agricultural soil-engaging components.

To elucidate the wear mechanisms of the scraper in shield tunneling through sandy pebble strata, this study aims to achieve high efficiency and low wear during the tunneling process. We evaluate the operational parameters and tool wear characteristics of a 9-m diameter spoke-type shield machine used on the Beijing Daxing Airport Line. The analysis focuses on the wear values of the scrapers and rippers, wear of the scraper in different wear forms, and scraper wear relative to the position of the rippers obtained from the field. The study yielded the following conclusions. The wear values of scrapers on different spokes vary significantly owing to ripper protection. The wear of the scrapers can be categorized into six types: tooth chipping, local damage of teeth, wear of side teeth, wave-type of wear, wear on intermediate teeth, and flat wear, with the majority exhibiting wear on the side and intermediate teeth. The 0 degrees spoke maintained the initial shape of the scrapers, making it more suitable for tunneling in sandy pebble strata. Based on the differences in the relative positions of the ripper and scraper, a model is proposed to determine the ripper plowing influence area. It was found that this area depends on the geological conditions of the soil; thus, the influence angle of ripper plowing in the considered sandy pebble strata is determined to be between 35 degrees and 50 degrees. The results obtained in this study provide a theoretical reference for optimizing scraper layouts in shield construction, even when operating under varying geological conditions.

A share-point is a cutting edge of the ploughshare, the crucial component of a horizontally reversible plough (HRP). Our previous trials in sandy loam soil indicated that severe abrasion/attrition wear with white materials appeared at the share-point in the high-speed shifting tillage operation of the HRP. This mechanical fatigue was demonstrated to be caused by the flowing soil-tool interaction. But whether the white materials are associated with the thermal effects due to the high-speed tillage is not known. This paper extended our previous work to evaluate the thermal effects by using a combined multi-body dynamics analysis (MDA) and fluid-solid-thermal simulation. The dynamic interaction between soil and share-point was studied with the MDA approach. Based on the generated tillage forces through the MDA, a fluid-solid-thermal model of the ploughshare was developed to investigate the specific quantitative results, maximum stresses and temperatures observed at the share-point, which were further compared with the published worn-lands at the same tillage conditions (such as tillage speed and depth). The comparisons showed that the maximum coupled stresses and tillage temperatures in this study both appeared at the share-point, particularly at the most severe abrasion/attrition with white materials, and that they were both varied with the different working conditions or the different tillage behaviours. Our findings demonstrate that the high-speed shifting operation of HRP has the thermal effects on the share-point wear due to the fact that the greatly varied tillage temperatures can accelerate to impact the surface integrity because of the thermal stresses detrimental to the micro-shape or size shape at the share-point section. This result may add to the knowledge base usefully applicable to the design of the high-speed mouldboard.

Tire wear particles (TWPs) attract attention because of their harmful impact on the soil ecosystem. Nevertheless, there is limited understanding regarding how aging affects the toxicity of TWPs to soil microorganisms. Herein, a microcosm experiment was performed to compare the toxicity of pristine and UV-aged TWPs on the soil microbial community. After 28 days operation, more holes and cracks appeared on the surface of the UV-aged TWPs compared with the pristine TWPs. The diversity and community structure of soil microorganisms changed under the pristine and UV-aged TWPs exposure, with the UV-aged TWPs significantly altered nirK-type soil denitrifying bacteria. Streptomyces played an important role in connecting the nirK-type bacterial community and promoting the denitrification process under the UV-aged TWPs exposure. The soil microorganisms further promoted the membrane transport of metabolites to resist the toxic effects of UV-aged TWPs by up-regulating the ATP-binding cassette (ABC) transporters, which consumed lots of energy and led to interference in energy metabolism. Furthermore, UV-aged TWPs further stimulated the accumulation of reactive oxygen species (ROS), stimulated the soil microorganisms to secrete more extracellular polymers substances (EPS) and activated the antioxidant defense system against oxidative damage caused by UV-aged TWPs, however, the activation of SOS response in turn increased the risk of antibiotic resistance genes (ARGs) transmission.

This paper focuses on the use of rotary-percussive drilling for hard rocks. In order to improve efficiency and reduce costs, it is essential to understand how operational parameters, bit wear, and drilling performance are related. A model is presented therein that combines multibody dynamics and discrete element method (DEM) to investigate the influences of operational parameters and bit wear on the rate of penetration and wear characteristics. The model accurately captures the motion of the bit and recreates rock using the cutting sieving result. Field experimental results validate the rod dynamic behavior, rock recreating model, and coupling model in the simulation. The findings indicate that hammer pressure significantly influences the rate of penetration and wear depth of the bit, and there is an optimal range for economical hammer pressure. The wear coefficient has a major effect on the rate of penetration, when wear coefficient is between 1/3 and 2/3. Increasing the wear coefficient can reduce drill bit button pressure and wear depth at the same drill distance. Gauge button loss increases the rate of penetration due to higher pressure on the remaining buttons, which also accelerates destruction of the bit. Furthermore, a more evenly distributed button on the bit enhances the rate of penetration (ROP) when the same number of buttons is lost. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. 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/).

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.

In order to overcome the obstacles of poor wear resistance and complex preparation process of the traditional tillage soil-engaging parts, this study presents a powder laying-feeding multi-material additive manufacturing method based on selective laser melting (SLM), to fabricate the heterogeneous material tillage parts with 316 L stainless steel (316 L) as the part-body and high entropy alloys (HEAs)-diamond composites as the part-blade. The microstructures including SLM forming quality, interfacial bonding of heterogeneous material, graphitization of diamond and interfacial behavior of diamond/HEAs matrix are systematically investigated. The results indicate that, adopting medium laser energy density 79.4 J/mm(3) of the composites during same-layer deposition, the overlapping area of 316 L/composites exhibits metallurgical bonding with high relative density of the composites section. Only slight graphitization of diamond happens and similar to 2 mu m width diffusion zone forms between diamond and HEAs matrix, without harmful carbide formation. Moreover, compared with commercial 65Mn steel, the wear resistance (wear mass loss rate) and corrosion resistance (corrosion current density) of HEAs-diamond composites have been decreased by 28 times and 230 times, respectively. The hetero-material 316L-composites exhibits good interfacial bonding strength of 432.3 MPa with elongation of 11.2 %. This study not only results in a novel solution of tillage wear-resisting parts, but also provides a multi-material additive manufacturing technology for metallic heterogeneous components.

Skin-like bioelectronics offer a transformative technological frontier, catering to continuous and real-time yet highly imperceptible and socially discreet digital healthcare. The key technological breakthrough enabling these innovations stems from advancements in novel material synthesis, with unparalleled possibilities such as conformability, miniature footprint, and elasticity. However, existing solutions still lack desirable properties like self-adhesivity, breathability, biodegradability, transparency, and fail to offer a streamlined and scalable fabrication process. By addressing these challenges, inkjet-patterned protein-based skin-like silk bioelectronics (Silk-BioE) are presented, that integrate all the desirable material features that have been individually present in existing devices but never combined into a single embodiment. The all-in-one solution possesses excellent self-adhesiveness (300 N m-1) without synthetic adhesives, high breathability (1263 g h-1 m-2) as well as swift biodegradability in soil within a mere 2 days. In addition, with an elastic modulus of approximate to 5 kPa and a stretchability surpassing 600%, the soft electronics seamlessly replicate the mechanics of epidermis and form a conformal skin/electrode interface even on hairy regions of the body under severe perspiration. Therefore, coupled with a flexible readout circuitry, Silk-BioE can non-invasively monitor biosignals (i.e., ECG, EEG, EOG) in real-time for up to 12 h with benchmarking results against Ag/AgCl electrodes.

Surface layers of agricultural machinery working bodies are subjected to intensive abrasive wear during operation, which leads to rapid wear of equipment and reduction of its service life. To increase the wear resistance of the working surfaces of tools, the method of induction cladding using 'Sormait-1' materials is widely used. However, after coating, additional heat treatment is required, which improves physical and mechanical properties of the material and increases its durability. When using electrofriction technology (EFT) hardening, the surface of the parts is subjected to melting under the influence of electric arcs, which affects the surface characteristics of the coatings. In this work, two types of surface treatment of L53 steel were investigated: induction cladding using 'Sormait-1' material, as well as a combination of induction cladding and subsequent electrofriction treatment. The coatings were characterized and compared with the substrate in terms of the following parameters: microstructure, phase composition, hardness distribution, and friction-wear characteristics. After induction cladding of the Sormait-1 material, a dendritic structure was formed; however, subsequent electrofriction treatment resulted in a reduction of this dendritic structure, which contributed to an increase in the hardness of the material. The average hardness of the coatings after electrofriction treatment was 786 HV0.1, which is more than three times the hardness of the substrate. Furthermore, the influence of structural characteristics and hardness on abrasive wear resistance was examined in accordance with ASTM G65 international standards. Field tests were conducted on plough shares before and after electrofriction hardening to evaluate their performance. Each ploughshare was scanned with a structured 3D scanner before and after use in the field. From the scan data, the cutting-edge profile was calculated and three key parameters were determined: linear wear, volumetric wear, and mass reduction. According to the results of field tests, it was found that the service life of the blades hardened by electrofriction technology was 12%-14% higher compared to serial blades processed by induction cladding with the use of 'Sormait-1' material. Operational tests of hardened plough shares confirmed the results of laboratory tests and proved the advantages of electrofriction technology for increasing the wear resistance of soil tillage machine working bodies.

This study developed a gravel soil granular bed model using the discrete element method, elaborating on the core barrel drilling process by integrating bond-breaking and particle flow patterns. A quantitative description of the drilling process is achieved by defining bond-breaking efficiency. The results indicate that the force on particles near the drill tooth is the greatest, and this force increases with the core barrel feed rate, which enhances drilling efficiency and exacerbates wear on the drill tooth and guide bars. An increase in rotational speed raises the force on the particles in the boundary region, leading to deeper wear of the guide bar; however, the enlargement of particle voids near the drill tooth mitigates wear. Additionally, a coupled discrete element method and finite element method are developed to analyse the effects of drilling parameters on drill tooth deformation, revealing that the design of the open hole at the top of the drill can effectively reduce the maximum equivalent stress and wear depth. The conclusions drawn contribute to understanding particle mechanics, the particle bonding damage mechanism, and drilling mechanical behavior, providing a reference for optimizing drilling operations and drill design.