Development of Hard PVD Coating Systems for Machining Austenitic Stainless Steels
| dc.contributor.advisor | Veldhuis, Stephen | |
| dc.contributor.author | Hemmati, Alireza | |
| dc.contributor.department | Mechanical Engineering | en_US |
| dc.date.accessioned | 2022-09-26T20:19:09Z | |
| dc.date.available | 2022-09-26T20:19:09Z | |
| dc.date.issued | 2022 | |
| dc.description | PhD thesis on developing PVD coating systems for high speed machining of austenitic stainless steels | en_US |
| dc.description.abstract | Application of hard coatings was found to be a promising method in response to industry’s growing demand for improved productivity and avoiding high temperature in cutting zone. Cutting speed as a one of the major factors of productivity, significantly increase the heat generation and temperature in cutting zone. Therefore, using protective coatings with higher thermal stability is required to maintain the productivity at high level. This research investigated the effect of Al concentration in Ti1-xAlxN lattice with various x amount during high-speed machining of austenitic stainless steels. The results showed that higher up to a certain point, thermal stability, mechanical properties, machining performance of the coating improved. Above this point, a drop in properties was observed associated with a change in crystal structure. further development in coating properties was obtained by incorporating Ta into TiAlN coating. As a results, a significant improvement in mechanical properties, 25% prolonged tool life at higher cutting speed (650 m/min), better thermal stability and excellent oxidation resistance was obtained. Out of different coating architecture, the results showed that monolayer TiAlTaN coating showed best properties. | en_US |
| dc.description.degree | Doctor of Philosophy (PhD) | en_US |
| dc.description.degreetype | Dissertation | en_US |
| dc.description.layabstract | Recent developments in materials selections and machining processes have introduced hard-to-cut materials to the modern manufacturing industry. The ever-increasing demands for high-speed machining of hard-to-cut materials highlight the importance of efficient cutting tools protection with high-performance coatings. Physical vapor deposition is an effective method to alter superficial tool properties by applying a thin layer of hard coating and, thus, protecting the tool during the machining process. In recent research, Ti1-xAlxN coatings with various x content and Ti-Al-Ta-N-based coating has been developed for machining of austenitic stainless steel. Thermal stability, mechanical properties, oxidation resistance and machining performance have been evaluated. Results showed more than 25% improvement in tool life during high speed machining, significant increase in mechanical properties and higher oxidation resistance and thermal stability associated with incorporation of Ta into Ti-Al-N coating. | en_US |
| dc.identifier.uri | http://hdl.handle.net/11375/27870 | |
| dc.language.iso | en_US | en_US |
| dc.subject | PVD coatings | en_US |
| dc.subject | Machining | en_US |
| dc.subject | Stainless steels | en_US |
| dc.title | Development of Hard PVD Coating Systems for Machining Austenitic Stainless Steels | en_US |
| dc.type | Thesis | en_US |