Investigation of 3D printed parts on selective laser melting process

• Main Author: Chua, Gregory Kok Hong
• Other Authors: Wong Chee How
• Format: Theses and Dissertations
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/72649
• Institution: Nanyang Technological University

Selective laser melting (SLM) is a powder bed based additive manufacturing process that is capable of fabricating complex functional metallic components with densities up to 99%. In this' study, the effect of print locations on the tensile strength of the samples fabricated using the SLM process is performed. A total of 12 tensile coupons were fabricated at four different locations on a metal substrate in a single print. Micro computed tomography is used to identify and validate the total percentage of porosity in a sample. Furthermore, different sizes of porosity are characterised and analysed. Tensile tests are carried out to identify the ultimate tensile strength of the samples printed at different locations. The results show that the percentage of total porosity and printing locations have an influence on ultimate tensile strength. An increase in the number of porosities leads to reduced tensile strength of the samples. The results also illustrated that samples fabricated at different print locations exhibit individualized characteristics. Furthermore, a massive cluster of porosity in the sample is identified as the breaking point of during tensile test.