Date of Award

8-9-2024

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Engineering Technology

First Advisor

Sujan Kumar Ghosh

Abstract

MoS2 is a popular solid lubricant with limited application at room temperature due to its’ sensitivity to atmospheric oxygen and humidity. This thesis focuses on the stabilization of molybdenum disulfide (MoS2) coatings on aluminum substrates to enhance their tribological performance at room temperature. MoS2 exhibits exceptional lubricating properties in vacuum conditions, but its reactivity with atmospheric oxygen leads to the formation of abrasive molybdenum trioxide (MoO3), restricting its effectiveness in ambient environments. This thesis investigates the effects of a Chromium underlayer and the incorporation of MAX phase (Ti3SiC2) on the tribological performance and chemical stability of MoS2 solid lubricant. Physical vapor deposition (Sputtering) and Selective LASER sintering method was used for the fabrication of coatings. Tribological, chemical and Topographical analysis was performed to investigate the coatings’ properties. Findings indicate that both the Cr underlayer and MAX phase incorporation significantly improve the stability and performance of MoS2 coatings on aluminum substrates. Using an underlying chromium layer significantly improve the durability of coating by two times. In the presence of an underlying chromium the oxidation reduces by 5.6% when the samples are exposed to atmospheric air. Incorporation of MAX phase increases the durability by seven times. Results demonstrate that triple sintering cycles produce the best particle dispersion, while the addition of 10% MAX phase significantly enhances wear resistance and coating durability without markedly altering the coefficient of friction. This advancement extends the applicability of MoS2 to various industries, including aerospace and automotive, offering a potential solution for reducing friction and wear in mechanical systems under ambient conditions.

Download

Share

COinS