Browsing by Author "Adibah Amir, Ph.D"

3D printing is a promising technology with the potential to revolutionize the additive manufacturing industry. Recently, the application of metal-based 3D Printing has been widely used especially in the aerospace, medical, and automotive industry. However, the cost of such machines is expensive and thus restricts access to this technology for small and medium enterprises. Thus, moving from expensive Selective Laser Melting (SLM) to Fused Deposition Modeling (FDM) Technology is a good alternative. Currently, the greatest challenges in advancing a low-cost FDM Metal 3D printing technology are post-processing, parameters affecting the post processes, accuracy, mechanical properties and microstructure of the finished parts. This project aims to investigate the post-processing techniques for 3D printed copper composites using an FDM 3D printer. To achieve the aim of this research, a hardened steel nozzle designed for metal composite filaments was used. Post-processing steps included debinding and sintering to convert the copper polymer composite into pure metal. The research employed the Design of Experiments (DOE) approach, specifically the Taguchi method, for optimization. An L8 orthogonal test array was constructed to determine the optimized parameters for debinding and sintering holding times. The findings revealed that the debinding process significantly affected shrinkage and hardness. The samples exhibited an average shrinkage of 30.59%, except for two samples that turned into small pieces due to improper debinding holding time. The debinding and sintering parameters played a crucial role in the successful conversion of the copper polymer composite into pure metal. These findings contribute to making metal 3D printing more affordable and accessible, opening up opportunities in different industries and supporting sustainable manufacturing practices. In future research, it is important to work on improving the way researchers finish the 3D printed metal parts. This includes finding better ways to remove binders and fuse the metal particles together during post-processing. Researchers should also look into simplifying the post-processing steps and finding ways to print larger parts.

Malaysia produced its silica that are being sought after for advances applications such as glass making. Presently, being the world’s sixth largest exporter of processed silica sand, Malaysia is gifted with abundance with silica sand reserves and has approximately 148.4 million tonnes silica sand estimated by Department of Mineral and Geoscience Malaysia (JMG). In the year 2018, the global silica sand market was worth approximately USD7.4 billion and is projected to reach USD10.5 billion by year 2024. In this study, silica samples were supplied by Terengganu Silica Consortium (TSC), a local silica sand developer. The objective is to increase the purity of silica sand that meets the international standard for glass making industry by using mechanical ball milling technique. Through this technique, the extracted sand will be crushed through different variables of ball milling parameters, that are round per minutes (rpm) and machine usage time. The refined samples then were analysed using XRD and XRF to measure the percentage of silica. Characterisation with SEM reveals the effect on size reduction and morphology. Findings from study contribute to increase GDP in Malaysia through export of silica. In the year 2019, the export of silica sand in Malaysia is valued at RM120 million and is projected to increase in post pandemic era. From the results and analysis in this in study, it shows that the best optimization parameters for a fixed milling time at one hour with milling speed at 100 Revolutions Per Minute (RPM) and also a fixed weight of sand is through the usage of 20 milling balls, with representing Ball to Powder weight Ratio (BPR) of 10:1. For the 20 milling balls, the method succeeded in increasing the purity of silica from raw silica sand (85.37%) by +12.56%.