Scale Morphology Research Articles

Performance of Fe-33Ni-18Cr Alloy at High Temperature Oxidation

This paper investigates the performance of Fe-33Ni-18Cr alloy at high temperature oxidation. The samples were isothermally oxidized at three different oxidation temperatures, namely, 600 °C, 800 °C and 1000 °C for 150 hours. This alloy was ground by using several grits of SiC paper as well as weighed by using analytical balance and measured by using Vernier caliper before oxidation test. The characterization was carried out using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) and x-ray diffraction (XRD). The results show that, the higher oxidation temperatures, the weight gain of the samples were increase. Sample of 1000 °C indicate more weight gain compared to samples oxidized at 600 °C and 800 °C. The kinetic of oxidation of all samples followed the parabolic rate law. The surface morphology of oxide scale at lower temperature is thin and form a continuous layer, while at high temperature, the oxide scale develops thick layer with angular oxide particles.

Actin bundles play a different role in shaping scales compared to bristles in the mosquito Aedes aegypti

Insect epithelial cells contain cellular extensions such as bristles, hairs, and scales. These cellular extensions are homologous structures that differ in morphology and function. They contain actin bundles that dictate their cellular morphology. While the organization, function, and identity of the major actin-bundling proteins in bristles and hairs are known, this information on scales is unknown. In this study, we characterized the development of scales and the role of actin bundles in the mosquito, Aedes aegypti. We show that scales undergo drastic morphological changes during development, from a cylindrical to flat shape with longer membrane invagination. Scale actin-bundle distribution changes from the symmetrical organization of actin bundles located throughout the bristle membrane to an asymmetrical organization. By chemically inhibiting actin polymerization and by knocking out the forked gene in the mosquito (Ae-Forked; a known actin-bundling protein) by CRISPR-Cas9 gene editing, we showed that actin bundles are required for shaping bristle, hair, and scale morphology. We demonstrated that actin bundles and Ae-Forked are required for bristle elongation, but not for that of scales. In scales, actin bundles are required for width formation. In summary, our results reveal, for the first time, the developmental process of mosquito scale formation and also the role of actin bundles and actin-bundle proteins in scale morphogenesis. Moreover, our results reveal that although scale and bristle are thought to be homologous structures, actin bundles have a differential requirement in shaping mosquito scales compared to bristles.

Approaching 16% Efficiency in All-Small-Molecule Organic Solar Cells Based on Ternary Strategy with a Highly Crystalline Acceptor

Summary All-small-molecule organic solar cells (SM-OSCs) with a high power conversion efficiency (PCE) of 15.88% (certified 15.5%) are demonstrated by employing 4TIC as the additional non-fullerene acceptor (NFA) to construct ternary SM-OSCs. 4TIC is a highly crystalline acceptor with a similar molecular structure as 6TIC, the host NFA in the binary blend. The addition of 4TIC not only significantly enhances the crystallinity of the blend film but also maintains the desired face-on orientation in the proper multi-length scale morphology to improve both charge extraction and recombination in devices. As a result, the PCE of the ZnP-TBO: 6TIC-based SM-OSCs increases from 12.11% to 14.73% after the addition of 4TIC. For ZnP-TSEH: 6TIC-based SM-OSCs, the PCE increases from 13.54% to 15.88% (certified 15.5%) after the addition of 4TIC. The 15.88% efficiency is the best result for SM-OSCs reported to date.

Visualization of atomic scale reaction dynamics of supported nanocatalysts during oxidation and ammonia synthesis using in-situ environmental (scanning) transmission electron microscopy

Visualization of atomic scale reaction dynamics of supported nanocatalysts during oxidation and ammonia synthesis using in-situ environmental (scanning) TEM. Reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas–solid catalyst reactions and are crucial to the catalyst function. Supported noble metal nanocatalysts such as platinum are of interest in fuel cells and as diesel oxidation catalysts for pollution control, and practical ruthenium nanocatalysts are explored for ammonia synthesis. Graphite and graphitic carbons are of interest as supports for the nanocatalysts. Despite considerable literature on the catalytic processes on graphite and graphitic supports, reaction dynamics of the nanocatalysts on the supports in different reactive gas environments and operating temperatures at the single atom level are not well understood. Here we present real time in-situ observations and analyses of reaction dynamics of Pt in oxidation, and practical Ru nanocatalysts in ammonia synthesis, on graphite and related supports under controlled reaction environments using a novel in-situ environmental (scanning) transmission electron microscope with single atom resolution. By recording snapshots of the reaction dynamics, the behaviour of the catalysts is imaged. The images reveal single metal atoms, clusters of a few atoms on the graphitic supports and the support function. These all play key roles in the mobility, sintering and growth of the catalysts. The experimental findings provide new structural insights into atomic scale reaction dynamics, morphology and stability of the nanocatalysts.

Low Temperature Aggregation Transitions in N3 and Y6 Acceptors Enable Double‐Annealing Method That Yields Hierarchical Morphology and Superior Efficiency in Nonfullerene Organic Solar Cells

AbstractThermal transition of organic solar cells (OSCs) constituent materials are often insufficiently researched, resulting in trial‐and‐error rather than rational approaches to annealing strategies to improve domain purity to enhance the power conversion efficiency. Despite the potential utility, little is known about the thermal transitions of the modern high‐performance acceptors Y6 and N3. Here, by using an optical method, it is discovered that the acceptor N3 has a clear solid‐state aggregation transition at 82 °C. This unusually low transition not only explains prior optimization protocols, but the transition informs and enables a double‐annealing method that can fine‐tune aggregation and the device morphology. Compared with 16.6% efficiency for PM6:N3:PC71BM control devices, higher efficiency of 17.6% is obtained through the improved protocol. Morphology characterization with x‐ray scattering methods reveals the formation of a multilength scale morphology. Moreover, the double‐annealing method is illustrated and easily transferred and validated with Y6‐based devices, using the transition of Y6 at 102 °C. As a result, the PCE improved from 16.0% to 16.8%. Design of high‐performance acceptors with yet lower aggregation transitions might be required for OSCs to successfully transition to low thermal budget industrial processing methods where annealing temperatures on plastic substrates have to be kept low.

Distinction of two featherback species (Osteoglossiformes: Notopteridae) in India based on scale structure

The fish species are identified primarily based on their morphological and meristic characters and of late, the molecular markers too have been used for differentiating between different genera and species. Scale morphology and structure has been established as a tool in fish taxonomy. The present investigation shows the utility of scale in distinguishing two featherback species occurring in India, Notopterus notopterus (Pallas) and Chitala chitala (Hamilton). Morphology and ultra structure (using SEM) of the scales of both the species were studied. The scales of N. notopterus are granulated with bead like structures in the focus, extending into the anterior part whereas the focus is smooth in C. chitala. Based on the length/ width ratio, the scales are relatively longer in N. notopterus than C. chitala. The lateral line is relatively short in C. chitala with rounded anterior end and trifurcated posterior end whereas it is longer in N. notopterus with elongated anterior opening and rounded posterior opening. Other distinguishing features which separate these two species include intercirculus distance and width of the radial canal. Therefore, the scale of the featherback species in India may be successfully employed in distinguishing them.

Habitat conditions, spatial distribution and trichome morphology of different species of Tillandsia growing on trees on the Ilha Grande Island, Brazil

Epiphytes living in the canopy face the problem of being exposed to varying levels of air humidity, temperature and insolation, according to both local climate and growing site conditions. This study addresses interrelationships between a) vertical distribution of Tillandsia species on phorophytes of Ilha-Grande Island in tropical Brazil; b) micrometeorological conditions at the different epiphyte habitats and growing sites; c) diurnal changes in plant water content and d) morphological traits of Tillandsia leaves with respect to absorptive scales. For this purpose, five vertical zones of different height and exposure were defined within the canopy, which are characterized by specific epiphyte associations. It was found that the Tillandsia species are heterogeneously distributed within tree canopies. The most exposed sites are colonized almost exclusively by T. usneoides whereas less exposed zones are settled by different assemblages of all other considered Tillandsia species. Microsite conditions (temperature and humidity) were shown to be substantially different, with quite extreme conditions at the sites preferred by T. usneoides. Despite its apparently stressful habitat, T. usneoides showed the lowest decrease of daily water content. All considered Tillandsia species differed significantly with respect to size and density of their absorptive scales. Also, density and size of scales differed within the leaves in a species-specific manner. Tillandsia usneoides was distinctly different from all other considered species by showing the longest scales and a high scale density which was uniform over the leaves. The results demonstrate the unique ability of T. usneoides to cope with drought stress. The outcomes support the assumption that leaf and scale morphology of Tillandsia are correlated with habitat. Probably, a dense mat of filiform leaves covered with scales showing long wing cells – as shown by T. usneoides – is particularly suitable for harvesting atmospheric water.

Digital light microscopy to characterize the scales of two goatfishes (Perciformes; Mullidae).

The normal and lateral line scales from above the head and four flank regions were investigated in two goatfishes by using light microscopy to evaluate the microscopic characteristics of scale surface ornamentation from different body parts of these fishes and to add new morphological data for their discrimination. The body scales were removed and digital images captured with a Dino-Lite digital camera connected to a Leica compound microscope. The presence of both transverse and longitudinal radii was a distinctive characteristic for the scales of studied goatfishes. The most distinctive features of the key scales discriminating the two goatfishes were the scale shape, the presence of irregular grooves in scale surface, the presence of transverse radii in the lateral fields, and the availability of lepidont at the anterior field. The lateral line scale ornamentations were almost similar in two species; however, the lateral line canal was branching in Parupeneus heptacanthus. Scale extension index indicated that in both species, the dimension of normal key scales tends to the right, while the dimension of lateral line scales tends to the left. This study accentuated that scales from different body regions may exhibit variation in surface ornamentations, that scale morphology could successfully be used to discriminate the examined goatfishes, and that the use of fish scale microscopy is an easy and relatively rapid method and does not require fish sacrifice. Since fish identification is essential for the conservation and management of species, the use of scale morphology to this purpose appears particularly promising.

Process Chain Optimization for SWCNT/Epoxy Nanocomposite Parts with Improved Electrical Properties

Electrically conductive nanocomposites present opportunities to replace metals in several applications. Usually, the electrical properties emerging from conductive particles and the resulting bulk values depend on the micro/nano scale morphology of the particle network formed during processing. The final electrical properties are therefore highly process dependent. In this study, the electrical resistivity of composites made from single-walled carbon nanotubes in epoxy was investigated. Three approaches along the processing chain were investigated to reduce the electrical resistivity of nanocomposites-the dispersion strategy in a three-roll mill, the curing temperature, and the application of electric fields during curing. It was found that a progressive increase in the shear forces during dispersion leads to a more than 50% reduction in the electrical resistivities. Higher curing temperatures of the nanocomposite resin also lead to a decrease of around 50% in resistivity. Furthermore, a scalable resin transfer molding set-up with gold-coated electrodes was developed and tested with different mold release agents. It has been shown that curing the material under electric fields leads to an electrical resistivity approximately an order of magnitude lower, and that the properties of the mold release agent also influence the final resistivity of different samples in the same batch.

Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents

The influence of boron on the oxidation resistance of conventionally cast U720Li alloy was investigated at 1130 °C and analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and electron probe microanalysis (EPMA). It has been found that the boron-undoped and -doped alloys all obey a super-parabolic rate law, but the oxidation rate is obviously increased by the boron addition. These alloys all show non-uniform oxidation between dendritic and interdendritic areas due to the serious microsegregation, while the oxide scale morphology of the high-boron alloy is quite different from that of the boron-undoped alloy. For boron-doped alloys, in the initial stage of oxidation the outward diffusion of boron from borides formed in the interdendritic region results in the formation of discontinuous and non-uniform B-rich oxide layers beneath and inside the Cr2O3 layer, while as the oxidation proceeds further boron can also transfer from the B-rich oxide to outer layers which eventually leads to disappearance of the B-rich oxide layers. The formation of B-rich oxide layers destroys the continuity of Cr2O3 layer and decomposition of B-rich oxide layers makes Cr2O3 layer more porous, which significantly reduce the protective property of the Cr2O3 layer and in turn decrease the oxidation resistance. Moreover, the eutectic (γ + γ′) highly enriched in Ti, Al is prone to be oxidized and form a thicker scale than the other regions, and hence the significant increase of its precipitation with boron addition also contributes to increasing the oxidation rate.

Selective Hole and Electron Transport in Efficient Quaternary Blend Organic Solar Cells

Summary Multi-component organic solar cells (OSCs) comprising more than two donor and acceptor materials have attracted significant research attention, as they can offer broader and better absorption, hence increasing solar cell performance. However, the morphology of multi-component OSCs is exceptionally complicated and challenging to control. Here, we develop a highly efficient (near 17.7%) quaternary OSC (q-OSC) using two polymer donors (namely PM6 and PTQ10) along with a fullerene (PC71BM) and a non-fullerene acceptor (N3). Our quaternary system demonstrates a new type of “rivers and streams” functional hierarchical (multi-length scale) morphology, where small domains of PTQ10 and PC71BM act as separators that spatially separate PM6 and N3, which effectively suppressed charge recombination, enhanced hole transport, and balanced charge transportation. These improvements in the quaternary system contribute to the increased internal quantum efficiency (IQE) and, thus, lead to an excellent JSC and device performance, which surpass their respective binary and ternary OSCs.

Otolith and Scale morphology of Endemic fish Cyprinion macrostomum in Tigris–Euphrates Basin

The present study aims to determine the otolith and scale morphology of Cyprinion macrostomum in the Tigris–Euphrates Basin. A total of 50 specimens are evaluated, and total length and body weight values of samples are ranged 6.7–10.4 cm, and 2.7–10.9 g, respectively. The asteriscus and lapillus pairs are examined, and also the scales from the six body regions of juvenile and adult C. macrostomum samples are investigated. The otolith characters such as shape, size, proximal and distal surfaces, antirostrum and rostrum types and the scale morphological characters such as type, size, shape, focus position, circuli appearance, radii type, and rostral and caudal margin shapes are the distinguishable characters for the C. macrostomum samples. Whereas asteriscus pairs shape is discoidal, lapillus pairs shape is kidney-shaped for C. macrostomum samples. When the scales in six different body regions of C. macrostomum are compared, there are differences between the scale shapes obtained from six different regions.

Convergent Evolution of Broadband Reflectors Underlies Metallic Coloration in Butterflies

Butterfly wings often display structural colors, which are the result of light reflection from chitinous nanostructures that adorn the wing scales. Amongst these structural colors are broadband metallic reflections, which have been previously linked to an ultrathin broadband reflector in the nymphalid butterfly Argyrophorus argenteus. To test if similar optical modes of broadband, specular reflectance have evolved in other butterfly taxa, we characterized the reflective scales of eight species from five Papilionoidea families using microspectrophotometry (MSP), light microscopy in reflected and transmitted modes, and scanning electron microscopy (SEM). In Nymphalidae, Pieridae, and Hesperidae, and Lycaenidae, we find that broadband specularity is due to spatial mixing of densely juxtaposed colorful reflectances that change across microscale distances (e.g. 1-3 µm). These seemingly convergent silver scales are unpigmented, show a continuous upper lamina with reduced windows, and consist of an air-cuticle sandwich of variable thickness, forming an undulatory thin-film. Strikingly, Hypochrysops apelles (Lycaenidae) show a novel mode of silver reflectance with spatial color mixing occurring across the entire proximo-distal length of the scale (>100 µm), transitioning from blue to red hues between the stem and the tip of the scales. Unlike the undulatory type, this reflector shows flat thin-films but this includes a multilayered lower lamina responsible for selective color iridescence in other lycaenids or in sunset moths. Finally, the gold scales of Anteros formosus (Riodinidae) show mixed reflectance in the green-to-red range, seemingly produced by a thin film in the lower lamina. Our comparative study suggests that evolution of metallic broadband reflectance repeatedly involved spatial color mixing and unperforated upper laminae, and is accomplished using at least three types of ultrastructural modifications. Undulatory thin-film systems, based on geometric adjustments of the transverse profile of the upper lamina and scale lumen, are widespread and may have evolved repeatedly from more generic colorless scale morphologies, while lycaenid and riodinid broadband reflectors may be elaborations of pre-existing iridescent states.

Effect of Y Additions on the Oxidation Behaviour of Novel Refractory High-Entropy Alloy NbMoCrTiAl at 1000 °C in Air

In this work, the influence of 0.5 at.% and 1 at.% Y additions on the high-temperature oxidation resistance of the equiatomic alloy NbMoCrTiAl at 1000 °C in air was investigated. Continuous isothermal and cyclic thermogravimetric experiments were conducted to characterize the oxidation kinetics of the alloys. Various analytical methods such as X-ray diffraction and electron microscopy with energy-dispersive X-ray spectroscopy were used to study the growth, morphology and composition of the oxide scales. It was found that the Y additions led to the formation of Al2Y phase along grain boundaries. The isothermal oxidation experiments of both Y-containing alloys showed lower oxidation rates after a short period of transient oxidation probably due to a reduction of fast-growing and voluminous Nb2O5 oxides within the oxide layer. During the steady-state period, however, oxidation of Al2Y caused local stresses resulting in crack formation and subsequent breakaway oxidation, i.e. pronounce increase in the oxidation rates. The cyclic oxidation experiments revealed lower oxidation rates and thinner, more adherent oxide scales formed on the alloy NbMoCrTiAl1Y compared to NbMoCrTiAl. The increased scale adherence was attributed to the formation of pegs due to the oxidation of Al2Y phase at the oxide/metal interface.

Synthesis and Application of a Phosphorous-Free and Non-Nitrogen Polymer as an Environmentally Friendly Scale Inhibition and Dispersion Agent in Simulated Cooling Water Systems.

A novel phosphorus-free and non-nitrogen scale inhibition and dispersion agent was synthesized from epoxysuccinic acid (ESA), itaconic acid (IA), and sodium methyl propylene sulfonate (SMAS). It was characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and elemental analysis, and its molecular weight and distribution were determined by gel permeation chromatography (GPC). Static experimental methods were used to evaluate the scale inhibition against CaCO3, Ca3(PO4)2, and CaSO4. The dispersion ability was evaluated by measuring the dispersive property of iron oxide. By observing the morphology of the CaCO3 scale, the scale inhibition mechanism was discussed. The results showed that when the ratio of raw materials (ESA/IA/SMAS) was 10:10:5, the scale inhibition rate of CaCO3 and CaSO4 reached 100% with the dosages of 20 and 10 mg/L, respectively. In addition, the scale inhibition rate against Ca3(PO4)2 was up to 96.64% with a dosage of 100 mg/L. The property of dispersing iron oxide exhibited the best results with 50 mg/L of the agent. On the 21st day, the biodegradation rate reached 63.33%. This polymer was an environmentally friendly antiscale and dispersant with good scale inhibition and biodegradability.

Manipulation of crosslinking in photo-induced phase separated polymers to control morphology and thermo-mechanical properties

Photopolymerization-induced phase separation allows significant control over polymer morphology and properties for hybrid radical/cationic systems. Polymer nano/micro-structure and domain size/continuity of each incompatible phase can be manipulated by using different photopolymerization conditions and formulation chemistries. In this work we incorporate multifunctional monomers including hexanediol diacrylate (HDDA) and a hybrid acrylate-oxetane monomer (OXMA) to modify the domain size scale and phase-separated morphology of a butyl acrylate (BA) and difunctional oxetane (DOX) system. Photopolymerization of the DOX/BA system results in distinct and co-continuous soft acrylate and hard oxetane domains. Incorporating different amounts of HDDA or OXMA generates polymer morphologies with smaller size-scale continuous hard domains because of the reduction in time difference between phase separation onset and gel point. Additionally, thermomechanical analysis shows that two glass transition temperatures (Tg's) are created for the DOX/BA system as indicated by the tan(δ) profiles, confirming the formation of distinct phase-separated domains. The addition of a crosslinker significantly increases the Tg of acrylate-rich domain as much as 45 °C, forming less distinct and broad tan(δ) peaks. The formation of more integrated as well as small and continuous domains enhances the flexibility and strength of the phase-separated DOX/BA system. A 2-fold increase in both elongation at break and maximum stress is observed with the addition of small amounts of HDDA or OXMA, resulting in an almost 5-fold increase in toughness and 2-fold increase in impact strength compared to the DOX/BA system. These results demonstrate that phase separation and polymer morphology in radical/cationic systems can be directed using multi-functional monomers enabling enhancements in mechanical properties including tensile toughness and impact strength.

X-ray-Excited Optical Luminescence Imaging for On-Site Analysis of Alumina Scale

On-site analysis of the composition, morphology, and thickness of surface scale on heat-resistant alloys helps to efficiently prevent serious problems such as failure and corrosion during their operation and to predict their remaining life. Currently, there are no analytical methods available that satisfy the requirements for the on-site analysis of oxide scale, which include short measurement time, nondestructive measurement, and portability of the analyzer. This study proposes a nondestructive analytical method to simultaneously identify alumina scale, which is one the most important protective oxide scales for base alloys, and to evaluate its morphology and thickness within 10 s by obtaining X-ray-excited optical luminescence (XEOL) images of the alloy surfaces. This was verified on Fe–25%Al, Fe–15%Al–10%Cr, and NiAl alloys heated at 900 or 1000 °C for different holding times. The XEOL images allow identifying alumina scale and observing its morphology from the infrared luminescence at 695 nm. The alumina scale thickness can be determined from the R value of the XEOL images in the range of 0.20–1.50 μm. The XEOL measurement can be performed in the air, and the setup primarily requires a digital camera and an X-ray tube used in portable analyzers such as X-ray fluorescence analyzer. The results suggest that the XEOL imaging method is suitable for the on-site evaluation of oxide scales on practical heat-resistant alloys.

Morphological Characteristics of Squaretail Mullet Ellochelon vaigiensis (Quoy and Gaimard 1825), a Rare Mugil Species Collected from the Iranian Waters of the Persian Gulf (Teleostei: Mugiliformes)

Detailed morphological information is provided for the Squaretail Mullet Ellochelon vaigiensis (Quoy and Gaimard 1825) from the Iranian waters of the Persian Gulf. The general morphology, saccular otolith, the urohyal bone morphology, and the scale morphology were described for this species. Approximately 21 years ago, the occurrence of E. vaigiensis was reported from the coastal waters of the Hormuzgan Province in the Persian Gulf (Southern Iran), based on only a single specimen, and since that only a few studies have addressed its occurrence from this region. Re-detection of E. vaigiensis in this study provided detailed data on its morphological characteristics from this region.

Effect of Jet Impingement Velocity and Angle on CO2 Erosion-Corrosion with and without Sand for API 5L-X65 Carbon Steel.

Most oil and gas production wells have plenty of corrosive species present along with solid particles. In such production environments, CO2 gas can dissolve in free phase water and form carbonic acid (H2CO3). This carbonic acid, along with fluid flow and with/without solid particles (sand or other entrained particles), can result in unpredictable severe localized CO2 corrosion and/or erosion–corrosion (EC). So, in this work, the CO2 EC performance of API 5L X-65 carbon steel, a commonly used material in many oil and gas piping infrastructure, was investigated. A recirculating flow loop was used to perform these studies at three different CO2 concentrations (pH values of 4.5, 5.0, and 5.5), two impingement velocities (8 and 16 m/s), three impingement angles (15°, 45°, and 90°), and with/without 2000 ppm sand particles for a duration of 3 h in 0.2 M NaCl solution at room temperature. Corrosion products were characterized using FE-SEM, EDS, and XRD. The CO2 EC rates were found to decrease with an increase in the pH value due to the increased availability of H+ ions. The highest CO2 erosion–corrosion rates were observed at a 45° impingement angle in the presence of solid particles under all conditions. It was also observed that a change in pH value influenced the morphology and corrosion resistance of the corrosion scales.

Analysis of Wear-Resistant Surface with Pangolin Scale Morphology by DEM Simulation

Based on the Discrete Element Method (DEM), an abrasive wear system composed of pangolin scale models and abrasive sand was established. The wear morphology of pangolin scale models under different velocities were simulated by PFC2D®. Their wear behaviors were discussed with regard to the contact bond fields, the contact force chains, the velocity fields and the displacement fields of the abrasive wear system. Moreover, the resistance of the pangolin scale models under different velocities were analyzed. In the DEM simulation, the fracture and debris locomotion on the scale model were observed at a meso-microscopic scale. The results show that the geometrical shape of the pangolin scale is helpful for decreasing the boundary stress, with the wear rate decreasing when the velocity is higher than 0.62 m·s−1. The wear rate is no more than 0.006 g/m under the abrasive sand, with a radius of 0.11–0.20 mm. The wear rates of the pangolin scale model agree with the experimental results, and the DEM provides a new way to study the abrasive wear behavior of this non-smooth biological surface.