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

Chockalingam, Mano
http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047

Abstract Details

2020, Master of Science, University of Akron, Mechanical Engineering.
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.
Gary L. Doll, PhD (Advisor)
Manigandan Kannan, PhD (Committee Member)
105 p.
Materials Science; Mechanical Engineering
micropitting; bearing steel; lubricant additives; water contamination; thermoplastics; tribology

Recommended Citations

Citations

  • Chockalingam, M. (2020). Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047

    APA Style (7th edition)

  • Chockalingam, Mano. Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel . 2020. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047.

    MLA Style (8th edition)

  • Chockalingam, Mano. "Micropitting Testing and Failure Analysis of High-Performance Gear Thermoplastics and Bearing Steel ." Master's thesis, University of Akron, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1607087595599047

    Chicago Manual of Style (17th edition)

akron1607087595599047
312
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This open access ETD is published by University of Akron and OhioLINK.