Shazarel Shamsudin

The recycling of aluminium chips as feedstock for new functional components contributes significantly to sustainable manufacturing while reducing landfill waste and raw material dependency. Nowadays, there is a rising need for cheaper, eco-friendly tool materials, especially for EDM. This study explores development of an eco-friendly EDM electrode fabricated from recycled AA6061 machining chips consolidated via hot extrusion and enhanced through copper electroplating. Extrusion temperatures of 450 °C, 500 °C and 550 °C were evaluated, followed by copper coating to investigate electrical resistance and coating thickness. The 550°C extruded sample showed the lowest electrical resistance (best results), with 14.55 mΩ resistance and a 4.62 µm coating. A full-factorial design of experiments (2 ⁴ with centre points) was applied to optimise CuSO ₄ concentration, pH, current and electroplating time (ET) effects. Statistical analysis confirmed the optimal coating achieved at 300 g CuSO ₄ , pH 3, 1000 mA and 3 h (ET), resulted in 8.55 mΩ resistance. In summary, these findings can support sustainable manufacturing, reduce CO ₂ emissions, and promote a circular economy worldwide.

This research addresses the escalating need for lightweight materials, such as aluminum and magnesium alloys, in the aerospace and automotive sectors. The study explores friction stir welding (FSW), a cost-efficient process known for producing high-quality joints in these materials. The experiment involved the welding of dissimilar aluminum alloys (AA5086-H111 to AA6061-T6) using a novel pin tool design with welding parameters such as holding time, pin tool length, tool spindle speed, and linear speed fine-tuned through a design of experiment (DOE) approach. A comparative analysis of two tool designs revealed that the newly introduced design substantially improved mechanical properties, particularly tensile strengths, by 18.2% relative to its predecessor. It is noteworthy that FSW joint efficiency is 83% when using a normal tool design in comparison with 92.2% when using a new tool design at similar FSW parameters. The new tool achieved the parameter values leading to the maximum tensile strength of 317 MPa with 3 mm thickness (Th), 25 s holding time (Tt), 0.1 mm dimension (L), 1600 rpm spindle speed (SS), and 30 mm/min feed velocity (Fr). In comparison, the normal tool achieved a maximum UTS of 285 MPa, 5 mm Th, 25 s Tt, 0.3 mm L, 800 rpm SS, and 90 mm/min Fr. The new tool design, with longitudinal and circular grooves, improves heat input for plastic deformation and alloy mixing during welding. Subsequent analysis of the joint’s microstructure and microhardness shows its similarity to the original alloys.

The solid-state recycling technique has gained significant attention for its ability to reduce metal losses, energy consumption, and solid waste. This study introduced solid-state recycling method to develop zirconia-reinforced AA7075/AA7050 aluminum chip-based matrix composite via a hot press forging process (HPF). The chips were cold-compacted at 35 tons and then hot-forged through a dog bone-shaped die. Full factorial and response surface methodology (RSM) designs were applied using Minitab 18 software. The Face Centred Composite (CCF) of RSM was adopted to rank each factor's effect and analyze interactions between input factors and output responses, followed by process optimization. The selected factors of temperature (Tp) and volume fraction of zirconia (ZrO2) nanoparticles (Vf) were set at 450, 500, and 550 °C with 5, 10, and 15 wt %, respectively. The analyzed responses were ultimate tensile strength (UTS) and microhardness (MH). SEM micrograph revealed a slightly uniform distribution of ZrO2 particles in the matrix. The developed composite gained the maximum strength of 262.52 MPa, a microhardness of 135.5 HV and a density of 2.828 g/cm3 at 550 °C and 10 wt % setting. RSM optimization results suggested 550 °C and 10.15 wt % as optimal conditions for maximum UTS and MH. The preheating temperature exhibited a more significant influence than the ZrO2 volume fraction on the composite's mechanical properties; however, both had a slight effect on grain size. The future prospects of this work are briefly addressed at the end. In conclusion, the HPF process was found to be an efficient recycling method for mitigating environmental impacts by conserving energy and materials.

Medical components made of titanium, steels, ceramic, and aluminium produced by metal injection moulding require different machining processes and creating a custom mould for each patient will limit the mould’s flexibility. This research aimed at developing a Polylactic acid (PLA)/Stainless Steel (SS316L) composite filament for 3D printing and investigating the influence of the compounding ratio on the mechanical properties of PLA/SS 316L polymer composite printed by Fused Deposition Modelling (FDM) machine. The effects of SS316L content and melting temperature on tensile strength and impact strength of printed samples were analysed at 2%, 7%, and 12% weight percentage (wt.%) and 200°C, 210°C, and 220°C respectively. The SS 316L powder was added to PLA by weight percentage (wt.%), and 0.4 mm diameter nozzle was utilized during printing. At a 12% addition of SS316L, the tensile strength (TS) and Charpy impact strength (IS) were maximised to 52.832 MPa and 0.1275 kJ/m² respectively. A decreasing trend was observed for both properties with 2% and 7% of SS 316L addition. Moreover, when the temperature was set to 220°C, the TS increased for all composites regardless of the weight percentage. The optimized parameter setting by RSM was 12 wt.% and 220°C revealed the TS and IS at 54.04 MPa and 0.172 kJ/m². The errors between the predicted and experimental values for TS and IS were 1.4% and 4.65%.

Energy efficiency in buildings plays a prominent role in the integrated urban development and environmental planning. By reducing the energy consumption of buildings, the environmental impact and carbon footprint are less, as well as costs for energy are reduced and optimized. The poor results from previous energy efficiency initiatives had forced the Malaysian government to launch National Energy Efficiency Action Plan for 10 years implementation period of 2016-2025 (NEEAP) after taking into account the socio-culture, policy, financial, and administration barriers. The objective of this study was to present and discuss the findings of the energy audit for the Alor Gajah Municipal Council (MPAG) building complex. MPAG will be able to save up to RM2,400,00.00 in energy spending between 2020 and 2030, should all the energy efficiency initiatives be fully implemented together with renewable energy. By investing in energy efficiency MPAG can achieve substantial energy cost savings throughout the facilities, demonstrate energy and environmental leadership, and raise self-awareness of the benefits of energy efficiency. This case study also summarises the recommendations for the implementation of energy efficiency in the building complex. Some suggestions are made in this paper as measures to improve the delivery mechanism. The Internet of Energy (IoE) is an implementation of the Internet of Things technology (IoT) will becoming a legal science tool to serve the purpose of a smart city.

The solid-state welding method known as friction stir welding (FSW) bonds two metallic work parts, whether the same or different, by plastically deforming the base metal. The frictional resistance between both metallic work pieces causes them to produce heat, which produces plastic deformation and welds them. However, the weldability and strength of FSW joints mainly depend on the FSW parameters. This review work highlights the previous research work on the FSW parameters and their effects on the weldability and quality of the aluminum alloys joined with similar and dissimilar metals through the FSW method. About 150 research studies were systematically reviewed, and the articles included data from peer-reviewed journals. It has been concluded that the key parameters, including welding speed, “rotational speed”, “plunge depth”, “spindle torque”, “shoulder design”, “base material”, “pin profile” and “tool type", significantly affect the weldability of the aluminum joint through the FSW method. Also, the selection of these parameters is important and fundamental as they directly affect the joint. It is recommended that future work focus on FSW for aluminum. Among these, the most essential is the application of artificial intelligence (AI) techniques to select the optimum FSW parameters for aluminum welding.

The current practice in aluminum recycling plants is to change the waste into molten metal through the conventional recycling (CR) manufacturing process. However, the CR technique is so energy-intensive that it also poses an indirect threat to the environment. This paper presents a study on meltless direct recycling hot press forging (DR-HPF) as an alternative sustainable approach that has fewer steps with low energy consumption, as well as preventing the generation of new waste. A laboratory experiment was conducted to study the mechanical properties and surface integrity of AA7075 aluminum alloy by employing a hot press forging (HPF) process under different temperatures (380, 430, and 480 °C) and holding times (0, 60, and 120 min). It was found that as the parameter increased, there was a positive increase in ultimate tensile strength (UTS), elongation to failure (ETF), density, and microhardness. The recycled chips exhibit the best mechanical properties at the highest parameters (480 °C and 120 min), whereas the UTS = 245.62 MPa and ETF = 6.91%, while surface integrity shows that the calculated microhardness and density are 69.02 HV and 2.795 g/cm³, respectively. The UTS result shows that the highest parameters of 480 °C and 120 min are comparable with the Aerospace Specification Metals (ASM) Aluminum AA7075-O standard. This study is a guide for machinists and the manufacturing industry to increase industry sustainability, to preserve the earth for future generations.

Compared to the recycling process by remelting, hot extrusion significantly reduces the energy consumption and CO₂ emission and ensures good mechanical and microstructural properties. This study investigates the effects of reinforcing aluminium AA6061 chips with mixed boron carbide (B₄C) and zirconia (ZrO₂) particles by employing a design of experiment (DOE) under 550 °C processing temperature and three hours preheating time. The findings showed that compressive strength (CS) and hardness increased with up to 5% added particles, and beyond 5%, the yielded values decreased because of materials agglomeration. However, the decreasing density was dependent on the addition of ZrO₂ particles. The distribution of particles with different volume fractions of mixed particles was investigated by employing SEM, AFM, and EDS tests. Thus, the process can produce a net shape structure that utilises material-bonding consolidation to provide sufficient support to reuse the recovered materials in engineering applications, such as in the automotive industry.

Direct solid-states, such as hot extrusion and equal channel angular pressing (ECAP), are alternative and efficient solid-state processes for use in recycling aluminium scrap. These processes utilise less energy and are eco-friendly. Ceramic particles such as ZrO₂ are suggested as alternatives in the production of metal composites. This study investigated and optimised the effects of various parameters of reinforced ZrO₂ nanoparticles on the mechanical and physical properties via response surface methodology (RSM). These parameters were the volume fraction (VF), preheating temperature (T), and preheating time (t). The effects of these parameters were examined before and after the heat treatment condition and ECAP. Each parameter was evaluated at varying magnitudes, i.e., 450, 500, and 550 °C for T, 1, 2, and 3 h for t, and 1, 3, and 5% for VF. The effect that process variables had on responses was elucidated using the factorial design with centre point analysis. T and VF were crucial for attaining the optimum ultimate tensile strength (UTS) and microhardness. Reducing VF increased the mechanical properties to 1 vol% of oxide. The maximum hardness of 95 HV was attained at 550 °C, 1.6 h, and 1 vol% ZrO₂ with a density of 2.85 g/cm³ and tensile strength of 487 MPa. UTS, density, and microhardness were enhanced by 14%, 1%, and 9.5%, respectively. Additionally, the hot extrusion parameters and ECAP followed by heat treatment strengthened the microhardness by 64% and density by 3%. Compression pressure and extrusion stress produced in these stages were sufficient to eliminate voids that increased the mechanical properties.