Modelling the heat transfer process in selective laser melting - numerical and experimental study

• Main Author: Ong, Roger Rui Feng
• Other Authors: Leong Kah Fai
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/60038
• Institution: Nanyang Technological University

Additive manufacturing (AM) is the process of creating three-dimensional (3D) solid objects of almost any shape from a digital model. It is also referred as 3D printing, and it works by adding layers of materials successively on top of each other, eventually forming parts of different shapes and sizes. It is different from conventional manufacturing methods, which operates by removing or forming materials from a bulk object. Selective laser melting (SLM) is a type of powder-based AM technique which is capable of creating figures from a 3D computer-aided design (CAD) model. At the moment, there is a growing interest in this technology to produce parts with complex geometry. In order to introduce SLM technique to manufacture real components into the industry, parts with good mechanical properties must be attained. Therefore, it is essential to analyse the different types of process parameters which will affect the quality of the product. In this project, powder-based material aluminium alloy 6061 (AA6061) is being studied. The focus of the project is to examine the melt penetration of laser beam on the alloy using the SLM technique. The aim is to have a better understanding of how different process parameters of the experiment would affect the melt penetration of the laser beam on the powder bed. In the first semester, preliminary work of this project includes the identification of an equation used in the simulation modelling of the 3D moving continuous Gaussian heat source. Simulation of the experiment using COMSOL program without a layer of powder has also been carried out. In the second semester, experimental measurement of melt width and melt penetration under different process parameters has been carried out. Future work of this project includes further improvisation on the equations used and discussion on the material molten and evaporated obtained from the simulation without powder.