Analysis of Lubrication Characteristics and Friction Test of Texture Topography of Angular Contact Ball Bearing Based on Computational Fluid Dynamics

Lubricants, Год журнала: 2025, Номер 13(2), С. 41 - 41

Опубликована: Янв. 21, 2025

A textured surface topography can be used to improve the lubrication performance of bearings. These improvements are closely related design topography. Therefore, studying effect rolling bearings on is significant. This study computational fluid dynamics (CFD) technology simulate and analyze an angular contact ball bearing under different working conditions. We studied influence a with area occupancy rates oil-phase volume fraction, as well bearing’s inner ring chamber at rotational speeds oil inlet speeds. conducted friction characteristic experiments point–contact pairs using wear tester. The effects loads characteristics smooth surfaces were analyzed. results indicate that fraction always higher than conventional in bearing. exhibited better performance. Different topographies have positive performance, conditions should fully considered achieve these improvements.

Язык: Английский

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Effect of Porosity on Tribological Properties of Medical-Grade 316L Stainless Steel Manufactured by Laser-Based Powder Bed Fusion

Materials, Год журнала: 2025, Номер 18(3), С. 568 - 568

Опубликована: Янв. 26, 2025

The potential of laser-based powder bed fusion (L-PBF) technology for producing functional components relies on its capability maintaining or even improving the mechanical properties processed material. This improvement is associated with microstructure resulting from high thermal gradient and fast cooling rate. However, this microstructural advantage may be counterbalanced by lack full density, which could tolerated to a certain degree applications such as biomedical implants medical equipment. In study, medical-grade 316L stainless steel specimens porosities ranging 1.7 9.1% were additively manufactured L-PBF using different combinations laser power scanning speeds. Tribological evaluated pin-on-disc testing in dry conditions against silicon nitride test body analyzed context characterization optical electron microscopy. results reveal that higher porosity allows diminishing wear rate, explained capacity pores retain debris related three-body abrasion. research provides practical insights into design wear-resistant components, thereby enhancing our understanding fields materials science engineering.

Язык: Английский

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Investigation of Basic Assumption for Contact Between Spheric Asperities in Rough Surface

Materials, Год журнала: 2025, Номер 18(1), С. 150 - 150

Опубликована: Янв. 2, 2025

Accurate analyses of contact problems for rough surfaces are important but complicated. Some assumptions, namely that all asperities can be approximated by a hemisphere with the same radius and assuming Gaussian distribution asperity heights, convenient may lead to less accurate results. The purpose this work is investigate these assumptions analyze conditions under which they valid. finite element method used construct spherical models different radii materials. validity assessed comparatively analyzing results four in terms loads, radii, average pressures yield strengths. show fully applicable elastic deformation. For plastic cases, lower strength two contacting bodies dominant factor affecting Assuming strength, ratio strengths spheres has an influence on characteristics range from 1.2 3, negligible when greater than 3. With equivalent ratio, analyzed detail, conducive clarifying application scope above assumption. reported study provides some theoretical basis model surfaces.

Язык: Английский

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The Characterization of Sliding/Pinning Behaviors of Water Droplets on Highly Adhesive Hydrophobic Surfaces

Surfaces, Год журнала: 2025, Номер 8(1), С. 1 - 1

Опубликована: Янв. 2, 2025

Sliding angle (SA) has been widely employed to describe the sliding behaviors of water droplets on substrates. However, it does not work highly adhesive surfaces since cannot slide along substrate even at a 90° tilt. In this work, novel strategy developed characterize sliding/pinning based collision between tilted and falling released from certain height. The critical (i.e., secondary angle, SSA) releasing height Hc) have introduced measured with help commercial equipment (drop shape analysis, DSA). Our results indicate that SSA, Hc phase diagram combination them well in describing makes possible distinguish different as adhesions them. It can act an efficient supplement conventional methods.

Язык: Английский

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Surface Wettability Modeling and Predicting via Artificial Neural Networks

Materials, Год журнала: 2025, Номер 18(1), С. 191 - 191

Опубликована: Янв. 5, 2025

Surface wettability, defined by the contact angle, describes ability of a liquid to spread over, absorb or adhere solid surface. wetting analysis is important in many applications, such as lubrication, heat transfer, painting and wherever liquids interact with surfaces. The behavior on surfaces depends mainly texture chemical properties Therefore, these studies show possibility modeling surface wettability adjusting parameters texturing process. prediction angle describing was performed using artificial neural networks. In order select most effective model, activation functions neurons, number hidden layers network training algorithms were changed. model presented capable predicting an efficiency coefficient determination R2 between real predicted angles over 0.9.

Язык: Английский

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Complex 3D surface structuring by means of laser chemical machining with modulated laser power

Journal of Laser Applications, Год журнала: 2025, Номер 37(1)

Опубликована: Янв. 29, 2025

Laser chemical machining (LCM) utilizes the thermal induced dissolution to remove material far below melting temperature. Material removal during LCM with modulated laser power depends on modulation frequency applied. The spatial of depth’s oscillation corresponds up threshold frequency. Above this threshold, depth remains constant. aim work is investigate whether could be used for surface structuring and its influence wetting behavior. Therefore, line scans different overlaps were generated create a structure titanium grade 1 using rectangular function output frequencies threshold. In addition overlap, phase angle between two neighboring lines was also studied. Subsequently, wide range structures achieved, including wavelike braidlike structures. wettability investigation highlighted considerable impact overlap behavior surfaces produced. While higher caused an isotropic wetting, lower anisotropic wetting. These results, thus, demonstrate first time possibility achieving by processing.

Язык: Английский

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Abrasive Flow Material Removal Mechanism Under Multifield Coupling and the Polishing Method for Complex Titanium Alloy Surfaces

Processes, Год журнала: 2025, Номер 13(2), С. 416 - 416

Опубликована: Фев. 5, 2025

This study addresses the challenge of uneven surface quality on concave and convex regions during precision machining titanium alloy thin-walled complex curved components. An electrostatic field-controlled liquid metal-abrasive flow polishing method is proposed, which examined through both numerical simulations experimental investigations. Initially, a material removal model for under field control developed, with computational fluid dynamics (CFD) discrete phase models employed simulations. Subsequently, motion characteristics metal droplets varying amplitudes alternating electric fields are experimentally observed within processing channel. serves to validate effectiveness proposed in enhancing uniformity across Our results demonstrate that by controlling distribution strengths, roughness differences between surfaces workpiece reduced degrees. Specifically, group subjected 24 V field, difference minimized 58 nm, representing 44% reduction compared conventional abrasive polishing. These findings indicate significantly enhances areas

Язык: Английский

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Springback mechanism and precision forming process of laser array flexible forming

Journal of Manufacturing Processes, Год журнала: 2025, Номер 139, С. 90 - 104

Опубликована: Фев. 17, 2025

Язык: Английский

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Adaptive Control of Pressure Difference in Abrasive Flow Machining for Inner Hole with High Depth/Diameter Ratio

Materials, Год журнала: 2024, Номер 17(24), С. 6123 - 6123

Опубликована: Дек. 14, 2024

To address the issue of uneven pressure distribution in abrasive flow field within inner hole components with a large depth/diameter ratio, an adaptive control strategy for regulating difference is proposed this paper. The was based on effects fluctuations at inlet and outlet patterns changes field, as derived from numerical simulations. An fixture also designed, enabling dynamic adjustments to gap, which significantly reduced field. Experimental results demonstrated that surface texture uniformity greatly improved after control. non-uniformity roughness 59.1% lower compared pre-control conditions, indicating machining consistency. Furthermore, maximum reduction increased 1.146 μm 1.844 μm, processing efficiency notably enhanced.

Язык: Английский

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Experimental Research on Behavior of Spontaneous Imbibition and Displacement After Fracturing in Terrestrial Shale Oil Based on Nuclear Magnetic Resonance Measurements

Processes, Год журнала: 2024, Номер 12(12), С. 2685 - 2685

Опубликована: Ноя. 28, 2024

Spontaneous imbibition (SI) effectively enhances oil recovery in shale reservoirs, significantly changing well shut-in and flowback design. This study conducted SI displacement experiments to simulate the stages so that mechanism of between crude fracture fluid can be discussed. In addition, relative contribution different types pores various effect wettability were determined with low-field nuclear magnetic resonance (LF-NMR) via each sample’s T2 transverse relaxation time at time. The experimental results show has multiscale pore structure characteristics combined micropores, small mesopores, mesopores. During process, is displaced from micropores by first, then a large amount production comes Oil water-wet core samples approximately 40.7%. oil-wet about 26%. affects samples. For process SI, recovered mesopores takes lead complete sample recovery. take After displacement, only 12% flooded research, demonstrating terrestrial several relevant affecting factors, contributes understanding fracturing retention reservoirs provides crucial theoretical foundations for development reservoirs.

Язык: Английский

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