Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel

Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel

Bibliographic Details
Main Author: Chockalingam, Mano
Language:English
Published: University of Akron / OhioLINK 2020
Subjects:
Mechanical Engineering
Materials Science
micropitting
bearing steel
lubricant additives
water contamination
thermoplastics
tribology
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-akron16070875955990472021-08-03T07:16:31Z Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel Chockalingam, Mano Mechanical Engineering Materials Science micropitting bearing steel lubricant additives water contamination thermoplastics tribology Gears and bearings play a critical role as machine elements in automotive and wind turbine applications. High-performance thermoplastics can replace metals for load-bearing applications such as gear teeth due to their exceptional thermal and mechanical properties. However, there is a general lack of micropitting performance data for high-performance thermoplastics. This study attempts to address this by evaluating and comparing the performance of several high-performance thermoplastic families of materials using a micropitting rig. Rolling element bearing components suffer from high Hertzian stresses in service that cause micropitting. The stresses experienced by these mechanical components depends on factors such as loading, the degree of sliding motion, material composition, lubricant chemistry, and lubricant water contamination. Premature failures of automotive and wind turbine gearboxes have been reported, and efforts have been made to prolong the reliable life of these machine elements. A review of literature suggests that a comprehensive study of how lubricant water contamination, lubricant chemistry, and base oil properties affect the micropitting and wear of the widely used 52100 bearing steel has not yet been performed. In addition to evaluating the micropitting performance of high-performance gear thermoplastics, this study also aims to establish an understanding of the micropitting phenomena in bearing steel and how it is influenced by tribological and lubrication conditions. A range of chemically active additives are formulated into mineral and synthetic oils to analyze their relative performance using techniques such as optical profilometry, ICP-MS, and SEM/EDS. The results show that polyamide-imides (PAI) have superior micropitting performance of the thermoplastics considered. This is due to their exceptional dimensional stability and mechanical strength at elevated temperatures. It is also seen that chemically active lubricant additives can promote micropitting and suppress mild wear in 52100 bearing steel. The addition of 1% deionized (DI) water into lubricating oils appears to promote earlier onset of micropitting damage, but mild wear is the dominant phenomenon. 2020 English text University of Akron / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047 http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Mechanical Engineering
Materials Science
micropitting
bearing steel
lubricant additives
water contamination
thermoplastics
tribology
spellingShingle Mechanical Engineering
Materials Science
micropitting
bearing steel
lubricant additives
water contamination
thermoplastics
tribology
Chockalingam, Mano
Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
author Chockalingam, Mano
author_facet Chockalingam, Mano
author_sort Chockalingam, Mano
title Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
title_short Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
title_full Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
title_fullStr Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
title_full_unstemmed Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel
title_sort micropitting testing and failure analysis of high-performance gear thermoplastics and bearing steel
publisher University of Akron / OhioLINK
publishDate 2020
url http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047
work_keys_str_mv AT chockalingammano micropittingtestingandfailureanalysisofhighperformancegearthermoplasticsandbearingsteel
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