- Title
- Influence of a saline test environment on the Fatigue properties of laser metal deposition Ti-6al-4v specimens
- Creator
- Botha, Sheldyn Jaye
- Subject
- Metal organic chemical vapor deposition
- Subject
- Salines
- Date Issued
- 2021-04
- Date
- 2021-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/59203
- Identifier
- vital:60304
- Description
- This study investigated the effects of the position of extraction and a corrosive environment on the fatigue properties of Ti-6Al-4V Laser Metal Deposition (LMD) specimens. Additive manufacturing (AM) processes allow for a reduction in manufacturing time, whilst constructing complex geometries. AM induces a complex thermal history which influences the microstructure in the material (1). The microstructure affects the fatigue properties where a finer microstructure is more favourable for increasing the fatigue life (2). Fatigue failure is one of the main modes of failure during a material’s service life (3). Thus, it is imperative to investigate the material’s fatigue behaviour. Major parameters of the LMD process were investigated, allowing bulk LMD coupons to be manufactured, from which fatigue specimens were extracted at three different heights. Static properties were attained through tensile testing and a Vickers Micro-Hardness evaluation. These properties allowed for calculating benchmark stresses that were utilised for fatigue testing. The biocompatibility of Ti-6Al-4V makes it desirable for medical implants – the core influence of this study. An implant is constantly subjected to a corrosive saline environment, introducing a corrosive mechanism of failure, known to decrease the life of a material. A rotary bending fatigue platform was utilised as it allowed for modifications to introduce a corrosive saline environment through means of a saline dosing system. Literature reports a higher possibility of corrosion fatigue occurring under rotary bending fatigue conditions for Ti alloy specimens (4,5). The fatigue data indicated no significant effect on the fatigue properties was evident when comparing the position of extraction, attributed to the interrupted build strategy utilised for manufacturing the bulk coupons. The specimens displayed a shift in fatigue life when subjected to a corrosive saline environment. Upon analysis, there was little variation in the microstructures at each position of extraction, attributed to the interrupted build strategy.
- Description
- Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2021
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (xiv, 170 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Engineering, the Built Environment, and Technology
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Botha, S.pdf | 8 MB | Adobe Acrobat PDF | View Details Download |