The research investigated the application of continuous coaxial laser cladding by powder injection as a surface treatment or coating process. The investigation aimed to establish the relationship between a change in the main laser cladding process variables and the geometry and characteristics of an Al-20wt-Si single pass clad layer formed on an Al 1370-F substrate using a Nd:YAG laser. The main process variables considered were: laser power, laser scanning velocity and the powder feed rate. The relationship between a change in the main laser cladding process variables and the geometry and characteristics of the clad layer was established by statistically analysing the variation in the process response with a change in the main laser cladding process variables. The process variables were varied based on a full-factorial, experimentally optimized test matrix. The clad geometry which is mainly defined by: the clad height, width, clad aspect ratio, depth of alloy penetration, and the clad root angle/wetting angle was investigated. In addition to the clad geometry several clad characteristics were investigated such as the dilution of the clad layer in the substrate material, the Vickers microhardness and microstructure of the clad crosssection, the powder efficiency of the process and the amount of visible defects. The study successfully established the relationship between the main laser cladding process variables and the clad geometry and characteristics. The secondary objective of establishing a suitable processing window by considering the relationship mentioned above was only partially met since it is believed that further refinement of the experimental cladding test setup and therefore also the experimental variable test levels is required.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nmmu/vital:9625 |
| Creators | Von Wielligh, Louis George |
| Publisher | Nelson Mandela Metropolitan University, Faculty of Engineering, the Built Environment and Information Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis, Masters, MTech |
| Format | xxii, 297 leaves, pdf |
| Rights | Nelson Mandela Metropolitan University |
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