JavaScript is disabled for your browser. Some features of this site may not work without it.
| dc.contributor.supervisor | Setswalo, K. | |
| dc.contributor.supervisor | Olakanmi, E. O. | |
| dc.contributor.author | Omogbehin, Gbenga Samson | |
| dc.date.accessioned | 2026-03-24T09:16:37Z | |
| dc.date.available | 2026-03-24T09:16:37Z | |
| dc.date.issued | 2025-04 | |
| dc.identifier.citation | Omogbehin, G.S.( 2025) Failure investigation and techno-economic analysis of remanufacturing damaged drive tumbler of a diamond mining shovel, Master’s thesis, Botswana International University of Science and Technology: Palapye | en_US |
| dc.identifier.uri | https://repository.biust.ac.bw/handle/123456789/741 | |
| dc.description.abstract | A critical but often overlooked stage in the remanufacturing of failed industrial components is failure investigation. Failure investigation involves the analysis of failure modes, mechanisms and root causes of failed components. In electric mining shovels, the drive tumbler is a critical component responsible for transmitting torque to the undercarriage system through continuous interaction of drive tumbler teeth with the crawler belt. However, this repeated engagement leads to high sliding-impact loading and frictional stresses, which result in premature failure of the drive tumbler in a diamond mine. The drive tumbler fails at approximately 5,000 running hours, below its expected service life of 25,000 hours. Despite the drive tumbler’s critical role in propelling the undercarriage system of mining shovels, research on failure analysis, to uncover root causes of its premature failure remains limited. Understanding the failure modes, mechanisms, and root causes of the premature failure of is essential for developing sustainable mitigation and remanufacturing strategies to enhance its resistance to wear and fatigue failure. This research aims to address these challenges by conducting a comprehensive investigation that includes engineering failure analysis (EFA), development of a mitigation strategy through the selection of suitable wear-resistant materials and remanufacturing technique, and a techno-economic analysis (TEA) of remanufacturing options. The EFA involved detailed chemical, macroscopic and microscopic examinations to identify failure modes, mechanisms and root causes. Observed failure modes include severe surface wear, adhesive wear, plastic deformation, cracks, and fractures on the drive tumbler teeth. Microscopic analysis via optical microscope of the undamaged drive tumbler teeth revealed a tempered martensitic microstructure, while scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) revealed manufacturing defects such as voids as well as alumina and manganese sulphide inclusions with a total of 3.75 volume fraction. Additionally, ion chromatographic analysis of water samples from the mining site confirmed high concentrations of corrosive ions such as chlorine and sulphur, with distinct peaks of approximately 1973 ppm and 2423 ppm, respectively. These emphasized the chemically aggressive nature of the drive tumbler’s operating environment. Fractography examination via SEM/EDS further uncovered multiple failure mechanisms including two-body sliding abrasion, adhesive-abrasive-fatigue wear, stress corrosion cracking, ductile-intergranular fatigue fracture, and sliding contact fatigue. The surface microhardness of the drive tumbler teeth was found to be approximately 353 HV, significantly lower than that of the mating crawler belt by 48% which contributed to premature failure of the drive tumbler. Other root causes established from EFA are direct metal-to-metal sliding-impact contact, presence of corrosive media and abrasive kimberlite ore particles in the diamond mine, manufacturing defects, and inadequate maintenance practices. To mitigate these challenges, this study recommends the adoption of metal matrix composites (MMCs) due to their exceptional hardness, wear-corrosion resistance, and mechanical properties, through a detailed literature review and the findings from EFA. Laser cladding (LC) emerged as a highly suitable materials deposition technique for the remanufacturing of damaged drive tumbler teeth owing to its ability to enhance surface properties. Additionally, findings from the TEA demonstrate that a hybrid approach combining wire arc additive manufacturing (WAAM) with LC to remanufacture surfaces affected by severe wear and adhesive wear yielded an annual cost savings of up to 93.3%, while refurbishing the teeth of newly acquired drive tumbler with laser cladding alone offers up to 44.8% cost savings per year. This research provides a detailed technical and economic framework towards remanufacturing failed drive tumbler, by identifying failure causes and mitigation measures to prevent premature failure. The recommended strategy offers a potential sustainable and cost-effective solution with significant implications for operational efficiency and profitability in the diamond mining industry. | en_US |
| dc.description.sponsorship | European Union (EU) for the Education for Laser-based Manufacturing (ELbM) scholarship Botswana International University of Science and Technology (BIUST)- postgraduate research grant Africa Laser Centre - research grant | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | Botswana International University of Science and Technology | en_US |
| dc.subject | Remanufacturing | en_US |
| dc.subject | Diamond Mining Shovel | en_US |
| dc.subject | Failure investigation | en_US |
| dc.subject | Techno-economic analysis | en_US |
| dc.subject | Drive tumbler | en_US |
| dc.title | Failure investigation and techno-economic analysis of remanufacturing damaged drive tumbler of a diamond mining shovel | en_US |
| dc.description.level | phd | en_US |
| dc.description.accessibility | unrestricted | en_US |
| dc.description.department | mie | en_US |
Files in this item
This item appears in the following Collection(s)
-
Faculty of Engineering and Technology
This collection is made up of electronic theses and dissertations produced by post graduate students from Faculty of Engineering and Technology