Key Engineering Materials Vol. 975

Abstract: Spent Bleaching Earth (SBE) is a solid waste produced from the palm cooking oil refining industry. The commercial ceramic membranes are quite pricey, therefore SBE solid waste is possible to be an alternative for reduction of membrane material cost due to high silica content. This work demonstrates the fabrication of ceramic tubular support membrane with varied SBE addition and investigates the functionalization group of its membranes. The ceramic support membrane was prepared from regeneration SBE with varied loading composition 15 and 35 wt%. The regeneration SBE using n-Hexane as solvent. Membranes were casted into tubular configuration using centrifugal casting technique at 3000 rpm. The tubular ceramic SBE membranes were dried and followed by calcined at 900°C with heating rate 2°C/min using programable furnace for 2 h. Both of raw SBE material and membranes were analyzed using Fourier transform infrared (FTIR). The SBE material after regenerated exhibits has high Si-OH and Si-O-Si peaks over raw material. Interestingly, the fabrication ceramic support membrane with tubular configuration is successfully preparation by centrifugal casting. Ceramic SBE membrane exhibits functionalization and deconvolution the present of siloxane, Al-OH-Al, Ti-O-Ti, and Al-O bands for both of 15 and 35wt% SBE loading. It concluded this tubular ceramic support membrane from SBE has appropriated chemical functionalize properties to applicates as membrane separation.

Abstract: Natural fibre matrix composites have been utilized in numerous industries, including the automotive, construction, and aerospace sectors. Maleic anhydride grafted polypropylene (MAPP) was used in this study to examine the effect of the coupling agent on the properties of a composite-produced using pineapple leaf fibre. The weight ratios of pineapple leaf fibre, polypropylene, and MAPP were 20g:180g, 15g:180g:5g, and 10g:180g:10g, respectively. The materials were mixed using a co-rotating twin-screw extruder machine at 170 °C and 50 rpm. The composite was then manufactured by injection molding at 185 °C. The mechanical and physical properties of PALF composite were examined by using a tensile test, impact test, and water absorption test. Thermal Gravimetric Analysis (TGA) was used to characterize the thermal properties of PALF/PP, and PALF/PP/MAPP composite. The surface morphology and fracture surface of the composite was characterized by using Scanning Electron Microscopy (SEM). Compared to the composite containing 5 g of MAPP, the tensile strength composite containing 10 g of MAPP produced a stronger interfacial bond. According to the impact test, adding more MAPP increases the material's strength and stress transmission. The average percentage of water absorption indicates low water absorption after the addition of the coupling agent. It can be concluded that the addition of a coupling agent improved the composite's properties.

Abstract: Additive Manufacturing (AM) is a technique in constructing components from a CAD model to a finished product. This is done by depositing molten material at a specific coordinate and height. This is done continuously until the finished product has been produced. Both FDM and PLA are well-known technology and material in the AM field. Optimizing the parameters will surely provide a good reach for hobbyists, researchers, and academicians. Optimization is a process concerned with the identification of the best possible value/condition for a certain parameter. Most research papers optimize a response/factor at a time given that less than five parameters are being studied. This paper aims to optimize three mechanical properties such as strength, elongation, and modulus of elasticity. This response was optimized through seven (7) benchmark parameters conducted in mixed levels (a combination of two and three levels). This paper was able to identify the optimum level per parameter, provide insight into the significant contributors affecting the target responses, and lastly, provide a contour plot to serve as a reference of AM end-users.

Abstract: This study examines the Markforged simulation software's efficacy in predicting properties of Markforged 3D-printed parts. Material extrusion (MEX) is widely used across industries for its ability to create intricate shapes with diverse internal patterns. To evaluate mechanical properties, especially due to varying infill patterns, the Markforged simulation tool is employed. Tensile test specimens based on ASTM D-638 were 3D printed using a Markforged Mark Two printer and "Onyx" material, varying layer thickness, infill pattern, and density. Deformation is simulated under a 500 N tensile load and compares to physical tests on a tensile machine, considering different pulling speeds. Results show minimal variation between simulations of solid infill patterns and experiments, regardless of speed. However, porous infill patterns exhibited notable differences. Tensile testing also revealed the impact of pulling speed on deflection for "Onyx" specimens under a 500 N load.

Abstract: This study focused on the development of 3D printing filaments suitable for fused deposition modeling (FDM) by recycling expired polylactic acid (PLA) filaments. The 3D printing filaments were processed into pellets by incorporating montmorillonite (MMT) nanoclay into the expired PLA filaments through twin-screw extrusion with varying concentrations of 1%, 3%, and 5 wt.%. These composite pellets were reprocessed to filaments through a filament extruder with a diameter of 1.75 mm. These filaments underwent different characterization techniques to test its mechanical and thermal properties. The thermal properties showed increasing values in the glass transition temperature, crystallization temperature, and melting temperature with a decrease in the specific heat upon incorporating increasing amount of MMT nanoclay. Furthermore, thermogravimetric analysis (TGA) showed a positive impact with better thermal stability when the MMT content was incorporated. In terms of mechanical properties, the study showed that the addition of 1 wt% MMT nanoclay, provided an increase in both the tensile strength and elastic modulus comparable to the virgin 3D printing PLA filament.

Abstract: 3D-printed polymer component parts and spare parts are now being widely used in various applications. In this paper, the 3D printing technologies and materials for spare part production in several applications are presented. Some opportunities and challenges faced when using 3d-printed spare parts are also discussed. The acrylonitrile butadiene styrene (ABS) has mostly been used. And it was found out that the durability of the spare parts could vary depending on the application.

Abstract: The global market size for Additive Manufacturing is predicted to be around USD 20 billion by 2025. The question arises whether conventional machining such as Computer Numerical Control (CNC) should be replaced by Additive Manufacturing (AM). The results presented in this paper are the outcome of an ongoing study. The overall objective of this study is a decision tool to decide which manufacturing route to adopt from a sustainability perspective. This paper will discuss the first phase of this study looking at the mechanical performance, cost and complexity of parts produced from AM and CNC. The results show that small parts are cheaper to fabricate by AM regardless of part complexity, whereas large, simple parts are cheaper to fabricate by CNC machining. These results might help in identifying manufacturing limitations of AM process in terms of mechanical performance and cost. These results will serve as inputs into a decision-making framework to decide on the most effective manufacturing route based on desired application such as in the spare parts in oil and gas industry.

Abstract: This research focused on the development of filament composite materials for fused deposition modeling (FDM) 3D printing applications. The main objective of this study was to fabricate and characterize poly (lactic acid) (PLA) filaments with varying amounts of alumina (Al₂O₃) nanopowder (0, 2.5, 5.0, and 10.0 wt.%). The resulting PLA/Al₂O₃ filament blends were produced using hot-melt extrusion. The filament blends were subjected to different characterization techniques and mechanical testing. The results indicate that the thermal stability of the filaments increased with increasing filler content. Furthermore, PLA with 5.0 wt.% nanoAl₂O₃ exhibited 55.84%, 66.14%, and 45.84% improvement in tensile strength, elastic modulus, and toughness, respectively.

Abstract: This study presents a comprehensive exploration of the fatigue resistance of wire arc additive manufacturing (WAAM) carbon steel for lattice structures. Microstructural analysis unveils substantial grain dimensions characterized by a distinctive crystallographic configuration. These grains exhibit equiaxed characteristics, demonstrating uniform dimensions in all directions. The prevailing microstructure is dominated by ferrite grains. In tandem with the microstructural insights, hardness evaluations were conducted in correspondence with the part's deposition direction. The analysis of these measurements unveiled a consistent base material hardness of approximately 159 HV. The uniform distribution of hardness profiles supports the deduction that WAAM carbon steel uniformly embodies strength attributes. This congruence aligns harmoniously with the uniform microstructure evident in microscopic analyses. The yield strength of the WAAM carbon steel exhibits higher values in the build direction, peaking at 392 MPa. The bending fatigue tests revealed a fatigue limit approximating 180 MPa for WAAM carbon steel, evident in both the build and deposition directions. Fatigue strength of WAAM carbon steel mirrors that observed for reference material S355MC steel sheet.