3D printing of silicon carbide

• Main Author: Tan, Richard Yong Heng
• Other Authors: Li Hua
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/75830
• Institution: Nanyang Technological University

Additive Manufacturing (AM), has increasingly been gaining popularity in the world of manufacturing due to the myriad advantages it encompasses. There is a variety of AM, and each AM is constructed with different raw materials in printing products to meet its specialised purposes for different uses. Likewise, different AM requires different raw material in printing the product. The resources selected for AM ranges widely from non-metallic to metallic material. Therefore, finding the right proportion of each material in creating the mixture is extremely essential. The focus of this project would be to determine the optimal mixture required to create an optimal 3D ink paste, through the use of robocasting technique with silicon carbide (SiC) powder. SiC offers good endurance and temperature strength, and it also has a high degree of hardness. Silicon carbide is a common material found in many applications such as non-metallic turbine engine, porous ceramics, space optics and mechanical parts. In addition, SiC is also widely use in 3D printing. A few possible ways in 3D printing of SiC, include lithography-cased ceramic manufacturing, binder jetting, laminated object manufacturing, and robocasting. However, the process in handling this material is extremely complicated. Therefore, finding the optimal mixture of 3D ink paste is a challenge. In the series of experiments conducted in this research, the SiC powder was first mixed with deionized water (DIW) to form a 3D ink paste, which would then be tested with two different dispersants Polyethyleneimine (PEI) and Polyacrylic acid (PAA). The amount of dispersant and DIW were varied in each experiment to find out the best condition for further testing in viscosity testing, density measurement and porosity testing. Viscosity testing was to conclude which is the most ideal formulation for holding shape after it has been extruded from the printer head. Furthermore, sintering were done on 17 samples which then were followed by density measurement and porosity testing with the use of Scanning Electron Microscope (SEM). It was concluded that the optimal formulation for PEI was 46%SiC, 7%PEI, 2%MC and PAA was 39%SiC, 7%PAA, 2%MC.