Design of reference samples of various porosity levels to assist in the detection of porosity produced by 3D printing to determine the accuracy of computed tomography scan

• Main Author: Muhammad Yunos Ab Rani
• Other Authors: Brian Stephen Wong
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/75245
• Institution: Nanyang Technological University

Porosity is used to describe any void or hole found in a material. However, characterizing them in terms of their size, shape, surface constituents and location is important in defining the specific defect and analysing the extent to which it will affect the material properties or functionality. There are multiple ways of detecting these defects, both through destructive testing and non-destructive testing. However, some of these methods have their own shortcomings, which limits the information that can be gathered about the defects. One type of non-destructive testing method used in the detection of these defects is 3D X-Ray Imaging via Computed Tomography Scan, or CT scan. A reference sample with designed porosities of various percentage levels were used in this Final Year Project to determine the accuracy of porosity detection using CT scan (Nikon XTH225ST). The reference sample was created using additive manufacturing, which is commonly known as 3D printing. The material selected to build the reference sample was Acrylonitrile butadiene styrene (ABS). The reference samples are essentially cylindrical discs with a variety of porosity level varying from 0.5% to 5.0% porosity. Various shapes such as spheres, cubes and cylinders were used to represent the different shapes and sizes of porosities. The sizes and location of these porosity varies within the reference samples. A comparison between calibrated values that was designed, and values extracted from CT data sets can be made, so that the accuracy of CT scanner can be evaluated.