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 …

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 …

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 …

Synthesis Of Ni-Based Intermetallics By Electrolytic Plasma Processing Of Ti And Ti-Based Alloys, Chuzhong Zhang

Material Science and Engineering Dissertations - Archive

EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.

This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as …

Inherently Porous Metal Structures With Sufficient Mechanical Properties Through Direct Writing Of Bio-Based Inks, Havva Eda Aysal

Graduate Theses, Dissertations, and Problem Reports (ETD)

There is currently a burgeoning interest in developing 3D printed metal structures with inherent porosity and sufficient mechanical properties for mass customization in the biomedical field. Current approaches for 3D printing of biocompatible metals rely on powder-bed fusion methods which are energy intensive and utilize large amounts of metal powder that is challenging to recycle. In addition, such methods aim on producing dense parts and porosity generation, within the printed part, is challenging due to the complex physics of the melting pool. Here, a relatively new and promising approach is undertaken to study the 3D printing of inherently porous structures …

Thermomechanical Mechanisms That Cause Adhesion Of Aluminum High Pressure Die Castings To The Die, Alex Monroe

Dissertations, Master's Theses and Master's Reports

In high pressure die casting (HPDC) of aluminum, cast material adhering to die is a significant defect. Adhesion occurs in two primary ways. The casting may stick preventing its removal from the die. Aluminum can also adhere to the die and buildup in local areas on the die surface with additional casting cycles. This second form of adhesion is called soldering. Lubricant is the best technology to control all forms of adhesion, but it comes at the cost of casting porosity, blisters, reduced die life, and increased die casting machine wear. New strategies to prevent adhesion are desired to eliminate …

Fretting Fatigue Behavior Of A Titanium Alloy Ti-6al-4v At Elevated Temperature, Onder Sahan

Theses and Dissertations

The purpose of this research is to investigate the fretting fatigue behavior of the titanium alloy Ti-6Al-4V at elevated temperature is investigated. Fretting and plain fatigue experiments are conducted at 260 °C. Crack initiation location and crack initiation orientation is measured and fretting and plain fatigue life data of the specimens from these tests are obtained. Fatigue parameters capable of predicting the number of cycles to specimen failure, the crack location and the crack orientation along the contact surface are analyzed. The parameters are calculated by using the computed stresses and strains obtained from the finite element analysis. The mechanisms …