Inconel 718 has widespread use in critical industries like aerospace, marine, and power generation. However, its challenging machinability, characterized by tool chipping/failure, and poor surface quality, remains a significant concern. Despite numerous efforts to enhance tool performance in machining hard-to-machine materials, the issue of sudden tool failure and chipping persists. This study presents an innovative in-situ tool treatment method, complemented by an optimized recoating strategy, aimed at tackling these challenges. The approach involves the application of a lubricating soft metallic Al-Si alloy coating to the tool’s faces, which can be recoated when needed. During subsequent Inconel machining, the Al-Si layer deposited on the tool melts due to high temperatures. The molten material fills microcracks on the tool surface, preventing their propagation. Moreover, the tool can slide on the beneficial tribo-films Al-Si layer which reduces friction, sticking, seizure, and built-up edge formation, resulting in decreased tool wear and chipping. The newly developed pre-machined recoating method has yielded promising outcomes, reducing cutting force and significantly improving tool lifespan compared to the PVD benchmark and uncoated tools. Additionally, this novel method enhances surface quality and minimizes undesirable microstructural alterations induced by machining. / Thesis / Master of Applied Science (MASc) / Chipping and excessive tool wear pose significant challenges in machining high-strength alloys like Inconel 718, limiting their applicability across various industries. According to research, conventional strategies used to deal with the machining challenges posed by Inconel 718 have not produced the best results. The goal of this research is to overcome the machining issues associated with such a difficult-to-cut material innovatively by depositing soft metallic coatings as a solid lubricant to enhance the machining performance. In this study, a cost-effective novel in-situ deposition technique with recoating capability as an alternative to conventional coatings is presented to achieve this goal. This innovative approach aims to improve tool performance during Inconel 718 machining significantly. This study also provides a thorough insight into the application of solid lubricants in machining, discussing their mechanisms, effectiveness, constraints, and potential to boost productivity and environmental sustainability. Furthermore, comprehensive investigations have been conducted to gain deeper insights into the prevalent wear mechanisms and surface treatments that can lead to improved machining performance for Inconel 718.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/29839 |
| Date | January 2024 |
| Creators | Mofidi, Asadollah |
| Contributors | Aramesh, Maryam, Mechanical Engineering |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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