Studying properties of slm fabricated parts and relating properties of slm parts to heat treated metal

• Main Author: Thong, Ming Chin.
• Other Authors: Chua Chee Kai
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/44481
• Institution: Nanyang Technological University

Selective Laser Melting (SLM) is an additive manufacturing (AM) technique used to produce M2 HSS parts with high density. It is mainly used in the bio-medical, aerospace and the jewellery field where parts are complicated in design and for small, customized productions. SLM is a technique that is gaining popularity; however, the parameters (materials, laser type and scanning speed) controlling the process are not completely understood. This results in most process parameters being derived experimentally for different conventional materials. This is not efficient as long hours must be put into experimentations. The first objective of the project is to understand the processing parameters of Titanium-Hydroxyapatite (Ti-HA) of 90% to 10% volume respectively. Ti-HA powder mixture is first prepared. After that, SLM parts are fabricated and tested to optimize processing parameters. However, the raw Ti powder that is used is found out to be unsuitable as it is not spherical and the experiments are not continued. The second objective is to develop an appropriate and novel heat transfer model to study the heating process of SLM. This model must be able to determine the thermal history of the material to provide important information for microstructure analysis. This model is formulated based on an adaption of the welding process model and then modified using theories of heat transfer for the solidification process. The model is simulated using Matlab and the graphs generated will require experimentation for verifications. Future works will require the re-mixing of the Ti-HA powder. Parts can then be created and the fabrication process can be optimized. For the mathematical model, experimentation is needed for verification of its validity. Thereafter, the model parameters will be refined for further research.