Tribology Commons^™

The Effect Of Mwcnt-Oil Impregnation Of Sintered Components On Their Wear And Corrosion Resistance, Maha Khaled Abdelfadeel

Theses and Dissertations

Powder Metallurgy (PM) offers an advantageous route for manufacturing complex and near net-shape components. Their inherent interconnected porosity that promotes the action of self lubrication compromises their structural integrity by creating pathways for corrosion and excessive wear. This research investigates the efficacy of Multi-Walled Carbon Nanotubes (MWCNTs) as a nano additive within the impregnating base oil (SN-150 base oil). An experimental matrix was designed to evaluate the influence of MWCNTs with different concentrations of 0.05, 0.1, and 0.2 wt.% and ultrasonic dispersion with varying sonication times of 30 and 60 minutes on the tribological and electrochemical performance of sintered steel …

Nissan Leaf Disassembly Tool And Test Stand Design, Mariah Z. Hodge

Williams Honors College, Honors Research Projects

The Akron Engineering Tribology Laboratory has developed a water-based lubricant and aims to test and observe if the water-based lubricant could work in an electric vehicle environment. As parameters for creating a test stand to mimic an electric motor environment are not readily available online, the goal of this senior design project is to take apart a used Nissan Leaf engine to define the parameters a test stand must meet to accurately recreate an electric motor environment. Knowing these parameters, a test stand will then be designed for testing the water-based lubricants. The purpose of building a test stand to …

Torque-Based Detection And Isolation Of Bucket-Specific Load Variations In A Continuous Bucket Ladder Excavator, Mason R. Krause

Dissertations, Master's Theses and Master's Reports

Understanding how cutter geometry, material, and operating conditions influence excavation performance is critical for the design of lunar surface systems operating in regolith environments. This work presents a torque-based methodology for detecting and quantifying bucket-specific load variations in a continuous bucket ladder excavator. A nine-bucket excavator was constructed to record drivetrain torque while operating in a regolith simulant over multi-day test periods. Each bucket featured a unique combination of cutting edge material and geometry. A method was developed to separate the continuous torque data into individual excavation events, enabling identification of individual bucket interactions. Analysis of the resulting event-based dataset …

Design New Stage For Vacuum Pin On Disk, Miranda Boyd

Williams Honors College, Honors Research Projects

For my senior design project, I am redesigning the moving stage for the vacuum pin-on-disk test used in the Akron Engineering Tribology Lab. This system is used to evaluate bearings and lubricants for aerospace applications under controlled vacuum conditions. The current stage design limits flexibility when adjusting for different testing parameters, so my goal is to develop a new movable stage that allows for varying weights and loads to be applied accurately and safely. The redesigned stage will improve test efficiency, adaptability, and precision, ensuring the system can accommodate a wider range of experimental conditions and materials while maintaining compatibility …

Kruss Modifications, Anderson W. Howard

Williams Honors College, Honors Research Projects

My project focuses on modifying a test device in the AETL to allow for high temperature test to be performed. I am also adding modifications to make it safer to perform tests using the high-pressure system.

Characterization Of The Fatigue Threshold Behavior Of Uhmwpe, Bethany B. Smith, Anurag Roy, Robert O. Ritchie, Lisa A. Pruitt

Faculty Journal Articles

Ultra-high-molecular-weight-polyethylene (UHMWPE) has been the material of choice for bearings in total joint replacements (TJRs) for decades as a result of its excellent wear resistance, chemical inertness, energetic toughness, low friction, and biocompatibility. Utilization of this polymer in orthopedic devices requires oxidation, wear, and fatigue resistance. Balancing these important properties by tailoring processing techniques and modulating microstructural features has been an ongoing endeavor in the field. Research into the clinical applications of UHMWPE has primarily focused on the challenges of wear and oxidation while studies into the realm of fatigue have been more limited. Literature gaps exist in fully understanding …

Fourier Analyses Of Optical Profilometry As An Inferential Measurement For Impact Coverage., Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A critical consideration in peening process design is achieving sufficient impact coverage. Conventional methods for assessing coverage rely on manual inspection, which is time-consuming and poorly suited for automated control. In this work, we investigate the use of frequency-domain analysis to quantify surface modification in peened samples using optical profilometry (OP) data. Three-dimensional surface maps of Almen strips were acquired using a high-resolution OP system and analyzed via fast Fourier transform (FFT) to compute spatial power spectral densities (PSDs). PSD maps and radially averaged profiles reveal consistent amplification of harmonic components similar to the nominal particle size, with increasing intensity …

Comparison Of Anti-Fouling Performance Of Textured Glass Surface Fabricated By Ductile-Mode Peening And Precision Grinding, Hayato Tagaya, Yutaka Kameyama, Shuhei Kodama, Hideaki Sato, Kento Shinagawa, Ayumu Sekiguchi, Seiji Hirai, Hitoshi Ohmori

15th International Conference on Shot Peening

Recently, there has been a growing demand for precision processing glass. In addition to dimensional accuracy, surface texturing to impart functional properties has attracted increasing attention. For example, anti-fouling performance against powder adhesion is required for cover glasses of solar cells. Powder adhesion is governed by van der Waals forces, which depend on the surface texture of the substrate, suggesting that surface structures influence adhesion behavior. Our previous study demonstrated that angled fine particle peening (FPP) could fabricate a nanoscale fine texture on glass surfaces through ductile-mode peening—glass processing without brittle fracture. In this study, the effect of surface texturing …

Wear Of High Entropy Alloys: Understanding Effects Of Cryogenic Temperatures And Surface Nitriding On Wear Behavior, Aubrey Yu Tang

Dartmouth College Ph.D Dissertations

Cryogenic tribological applications have become increasingly important with the development and innovation of advanced equipment in aerospace, polar regions, superconductivity, and more. Traditional lubrication methods are not viable under these harsh environments, so metallic materials must be able to maintain excellent mechanical properties and withstand the constant impact and wear alone. High entropy alloys (HEAs) have emerged as potential candidates for these applications because of their wide variety of excellent room temperature properties and apparent improvement of mechanical properties of some HEAs at extremely low temperatures. Despite their promising nature, very limited work has been done on understanding the wear …

Synergistic Enhancement Of Tribological Behavior And Colloidal Stability In Cuo Nanolubricants Via Ligand Tuning, Sherif Elsoudy, Sayed Akl Akl Dr, Sayed Akl A. Akl Dr, Esm Lane, Abas Hadawey, Philip D. Howes

Mechanical Engineering

Nanoparticle-based lubricants, or nanolubricants, can exhibit superior tribological properties compared to unmodified base oils. However, these performance gains are highly dependent on the nanoparticle surface chemistry, particularly in maintaining stable colloidal dispersions. This study explores the influence of oleic acid (OA) and oleylamine (OAm) functionalization on the tribological and colloidal properties of CuO nanoparticles dispersed in an SAE 20W50 base oil. We present a hybrid optimization framework combining Response Surface Methodology (RSM) with Bayesian Optimization (BO) to identify the optimal OA to OAm ratio (OA–OAm) for CuO nanolubricants. Unlike prior studies that employed either RSM alone or trial-and-error approaches, this …

Ultrasonic Cavitation Erosion Behaviour Of Plastically Deformed Textured Stainless-Steel Surface, Amit Raturi, Mayank Garg, Harpreet S. Grewall, Harpreet S. Arora

Mechanical Engineering Faculty Publications

In this study, we utilized an innovative pathway to obtain exceptional resistance to the cavitation erosion-corrosion behavior by combining surface texturing with severe surface deformation. Severe surface deformation was carried out using stationary friction process (SFP) followed by micro-texturing through a micro-imprinting approach. The textured sample after processing (SFP+T) had erosion resistance that was 6-7 times greater than that of the as-cast sample under ultrasonic cavitation conditions. In addition, the SFP+T sample was able to sustain a similar trend in the erosion-corrosion medium as well. Furthermore, the flow field characteristics of textured and nontextured samples were investigated using numerical calculations …

Design Strategy For Hybrid Thrust Air Bearings: Comparative Analysis Of Rigid Vs. Foil Bearings Considering Optimum Taper Angle And Orifice Location With Experimental Validation, Ehiremen Ebewele

Mechanical and Aerospace Engineering Dissertations - Archive

Gas foil thrust bearings (GFTBs) are contactless bearings that offer advantages such as lightweight construction and the ability to accommodate misalignments and geometric irregularities. However, their load capacity is lower than rigid or magnetic bearings. The structure and geometry of the foil significantly influence GFTB performance. The taper-flat design is the most used configuration due to its effectiveness and ease of implementation. Key parameters in designing this geometry include taper ratio, taper height, orifice size, and orifice location. These parameters must be optimized alongside manufacturing constraints to produce an effective GFTB. This study presents a design optimization investigation of various …

Nonlinear Bump Stiffness Model And Its Effect On Structural Stiffness And Nonlinear Rotordynamic Characteristic Of Foil Bearing, Woongeon Lee

Mechanical and Aerospace Engineering Dissertations - Archive

Bump foils are the most widely used in foil bearings, but the behaviors of bump foils are complicated, and their characteristics have been a focus of research for decades. Bump foils are usually modeled as stiffness and damping are accounted for through interactions with shaft eccentricity, loading, shaft speed and excitation frequency. These nonlinear characteristics of the bump foil of radial foil bearings can be observed during both manufacturing and operational processes because of their inherent structural properties such as bump geometry, forming process, age-hardening process and complicated contact behavior with bearing housing. These nonlinear characteristics are one of the …

Analysis Of Ptfe Radial Lip Seals For Wheel Bearing Applications, Madison Vogt

Theses and Dissertations--Mechanical and Aerospace Engineering

A numerical analysis was conducted to investigate the viscoelastic effects of nonlinear materials on the sealing zone and contact pressure distribution of radial lip seals in a conventional geometric topology. The use of nonlinear materials in radial lip seal applications is desirable to improve operation and reliability of rotating machinery due to their high operating temperatures, chemical compatibility, and low friction coefficients. Examples include, but are not limited to, seals within industrial air compressors, turbine engines, aircraft landing systems, chemical processing equipment, and Freon pumps. This work focuses on analyzing the nonlinear viscoelastic response of pure Polytetrafluoroethylene (PTFE) and PTFE …

In-Situ Informed Modeling And Characterization Of Friction And Built-Up Edge In Machining Of Aerospace Alloys, Avery Hartley

Theses and Dissertations--Mechanical and Aerospace Engineering

Machining is by no means a new manufacturing process. However, it is separated from other traditional deformation processes by its extreme temperatures and strain rates. The function and life of a multitude of products and mechanical components are dependent on the material properties induced by changing the surface through machining. Furthermore, the tools used within machining are often expensive and material reserves are sparse. The understanding the mechanics of the machining process, especially related to the friction of the tool and workpiece, helps to further the life of tools and parts to minimize economic and environmental impact.

Current friction modeling …

An Investigative Study Of Thermal Fluid Properties When Introducing Metallic Nanoparticles Through A Heat Exchanging System, Levi P. Mckinney

College of Graduate Studies: Theses & Dissertations

Heat-exchanging systems are essential in applications ranging from automobiles to air-conditioning units, and ongoing improvements aim to enhance efficiency while reducing system size. Conventional coolant upgrades often rely on ethylene glycol, which increases thermal stability and lowers freezing point but reduces water’s inherent heat-transfer capability. Advances in nanotechnology provide an alternative approach: suspending nanoparticles in base fluids can significantly modify thermal properties, with some formulations exhibiting conductivity increases of up to 60%. This thesis examines the thermal and tribological performance of three working fluids—distilled water, a 50:50 water–ethylene glycol mixture, and the same mixture enhanced with Al₂O₃ nanoparticles. Distilled water …

Measuring And Modeling Grease Degradation, Alan Gurt

LSU Doctoral Dissertations

Lubricating grease is an ideal lubricant for many devices such as roller bearings, journal bearings, slide bearings, gears, and many types of joints due to its simplicity. Once grease is put in place, it can often provide adequate lubrication for extended periods of time without the need for a complex supply system that would generally be needed for oil lubrication. However, during prolonged use, various degradation mechanisms change the physical and chemical properties of grease, possibly leading to inadequate performance and machinery failure.

In order to succinctly quantify the degradation of grease, it is essential to have robust, meaningful test …

Lifetime Prediction Of Pan Feeder Based On 3d Laser Scanning For Wear Assessment, Nony Maulidya, Dedi Priadi, D. Rizal Asral

Journal of Materials Exploration and Findings

Apron feeder is one of stages in crushing circuit to convey material in short distance. Pan flight is the main component of apron feeder that is severely exposed to wear mechanism due to its direct contact with open cut abrasive ore. With this operating environment of apron feeder, regular maintenance and inspection must be conducted to assess wear rate of pan’s surface to maintain equipment availability and provide information and sign before the equipment undergoes severe and sudden degradation. 3D laser scanning is method used in this study as Non-Destructive Testing (NDT) based inspection. The aim of using 3D scanning …

Understanding The Microstructure And Tribological Performance Of Cocrfeni-Based High Entropy Alloys, Ali Azarmi

All Theses

Due to their higher wear resistance compared to conventional alloys, high entropy alloys (HEAs) are now being considered as candidates for parts undergoing sliding contact during their lifetimes. While the engineering field has built some knowledge related to the performance of selected high entropy alloys, such as the CoCrFeNi alloy, more research is needed to determine if (how) expansions from four to five principal alloying elements alter the performance compared to the initial alloy. In this study, we started this research effort by investigating the relative performance of CoCrFeNiMn and CoCrFeNiTi with respect to CoCrFeNi. The two primary alloying elements …

Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain

Master's Theses

Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …