Key Engineering Materials Vol. 1025

Abstract: Friction stir welding (FSW), which is termed a green manufacturing process, is a very efficient method for joining magnesium alloys. In this research work, dissimilar Mg-Al-Zn magnesium-alloys have been welded at different operating conditions using FSW method with the aim of optimizing the tensile-strength (TS). The maximum value of TS was 234.86 MPa which was obtained at 15 mm of shoulder-diameter ( SD_Tool), 40 mm/min of welding-speed (WS) and 1000 rpm of tool-rotational-speed (TRS). Further, mathematical model for TS was developed to optimize the TS using desirability approach. The desirability approach predicts the optimized value 248.83 MPa at 15 mm of SD_Tool, 30 mm/min of WS and 1000 rpm of TRS.

Abstract: Sustainable material processing is the current need of machine tool industries. This paper aims to design and experimentally study the material removal rate of mild steel during dry turning using a high-speed steel single point cutting tool and a conventional lathe machine. Twenty-seven turning operations are designed using an orthogonal array experimental design method. The speed, feed and depth of cut are selected as input parameters while material removal rate is considered as quality parameter. Input parameters are varied twenty-seven times during dry turning of mild steel workpieces. Effects of input parameters are investigated to discover which one has a significant effect on material removal rate and hence to determine the dry turning conditions for mild steel. Statistical test results revealed that the depth of cut is significant than feed and speed. The F-value obtained from ANOVA result and Pareto chart are verified that depth of cut is significant on material removal rate of mild steel during dry turning

Abstract: This study investigates the influence of milling parameters on the material removal rate (MRR) of thick mild steel. The study employs a designed experiment to evaluate the influence of cutting speed, feed rate, and depth of cut on MRR. A total of nine milling experiments are conducted on mild steel using orthogonal array method. The study aims to identify the optimal process parameters for achieving a maximum MRR on mild steel workpieces. The value of signal to noise ratio (SNR) is used to evaluate the optimal values of milling parameters for thick mild steel. Higher-the-better type quality characteristic is used to evaluate the SNR of MRR. Further, MRR is analyzed using ANOVA method to elect the significant milling process parameters based on P-values and fisher coefficient. Depth of cut found the significant followed by feed rate and speed. The contribution of each milling process parameter is also evaluated. Depth of cut contribution is found 66% on MRR of thick mild steel

Abstract: Atmospheric pressure plasma modifies the surface properties of materials while preserving their bulk characteristics. Here, we show how an oxygen helium atmospheric pressure plasma can increase surface energy of 330 series stainless steel, a material used in biomedical and industrial applications. Plasma treatment was done with a commercial atmospheric pressure plasma reactor. Optical Emission Spectroscopy was performed to assess relative concentrations of plasma species present. In addition to demonstrating the effectiveness of this surface treatment approach, our results show that the increase in hydrophilicity is proportional to the concentration of reactive oxygen species present in the plasma suggesting that these species are important to the treatment process. Keywords: Surface modification; cold plasma; Reactive Oxygen Species

Abstract: Injection molding is one of the most extensively employed manufacturing methods to produce high quality part at high production rate. However, achieving high precision and quality product is still one of the biggest challenges in injection molding process. In this study, the optimal value of injection molding parameters is investigated. The initial injection parameters are determined using Moldflow software, then it is tested in experimental setup with feedstock composition of 90% Cu and 10% PA-6. After the experiments are done, the optimal combined response can be calculated Taguchi-grey-fuzzy method. Furthermore, ANOVA is done to measure how much contribution is given by each of parameters. From the analysis, it is given that 10 MPa and 9 MPa is the optimal value of both injection pressure and holding pressure respectively. It is also noted that the holding pressure had a higher contribution (39.62%) than injection pressure (13.13%) on the dimensional change and roundness.

Abstract: Recently, the development of eco-friendly 3D filaments became a focus of researchers in additive manufacturing. Polycarbonate is one of the common 3D printing materials made from petroleum and non-biodegradable materials. In this research, to create ecological filament, polycarbonate from water gallon plastic waste was recycled through the extrusion process. To produce a filament with a diameter of 1.75 ± 0.1mm, the rate of the screw used in the range of 17-19 rpm, and the puller speed in the range of 10 – 11 rpm. The obtained filament was printed by using Creality Ender 3 S1 Pro machine. Printability properties such as defects and adhesion to the bed were investigated. The tensile strength and impact resistance of the product in longitudinal and transversal infill directions was measured according to ASTM D638 and ASTM D6110 respectively. It was found that in general, the tensile strength, modulus elasticity, and elongation in longitudinal directions are higher than in transversal directions. The tensile strength of recycled filament and commercial filament in the longitudinal direction was 39.54 ± 2.53 MPa and 37.38 ± 5.91 MPa respectively. The results show that filament from polycarbonate plastic waste is a promising material used as an eco-friendly filament.

Abstract: The influence of polyamide-6 (PA6), polyamide-12 (PA12), and their compositions was analyzed to determine the rheological behavior of the feedstock with 43% solid loading. The feedstock with Cu/PA composite constituents were extruded into filaments. The sphericity of particles, particle distribution, and voids was identified using Scanning Electron Microscopy (SEM). The capillary rheometer method was utilized to examine how shear rate and temperature impact the results. The viscosity and shear rate of the material was assessed at different temperatures and shear rates using an L/D ratio of 20 mm and a diameter of 11 mm capillary rheometer. The test results indicated that the polyamide composition influenced the feedstock's rheological properties. The viscosity of the feedstock decreased with an increase in the polyamide composition. Feedstock Cu/PA6 with a composition of 14wt%-Cu has the higher rheological properties among the variation of other composition both for PA-6 and PA-12. Viscosity and Flow energy activation Cu/PA-12 higher than Cu/PA-6.

Abstract: A study was conducted on gamma-ray modified nanoHydroxyapatite (HAp)/Ultra High Molecular Weight Polyethylene (UHMWPE) composite as orthopedic implant material. This study aims to characterize the effect of gamma radiation on the physical, chemical, and mechanical properties of UHMWPE/HAp composites so that they can be used as orthopedic implant materials. The composite film was irradiated with gamma rays at a dose variation of 0 kGy, 15 kGy, and 30 kGy and a dose rate of 8 kGy/hour. Composites before and after radiation were tested for physical, chemical and mechanical properties. Physical properties test includes surface microstructure analysis; chemical properties test includes phase and functional group analysis; mechanical properties test, including hardness, tensile strength, and elongation at break. The results obtained are gamma radiation from IRKA changes the chemical properties of composites in terms of crosslinking and the number of radicals, as well as mechanical properties in terms of hardness, tensile strength, and elongation at break with different changes from the initial state before radiation. The best mechanical properties were obtained at 25% HAp composition in a dose of 30 kGy with a hardness (shore A) of 97.17; tensile strength of 18.15 MPa; and elongation at break of 17.85%, so that the UHWMPE/HAp composite has potential as an orthopedic implant material following the Ultimate Tensile Strength (UTS) of cancellous bone ranging from 10-20 MPa.

Abstract: Modern engineering components require composites that are robust, lightweight, and inexpensive as integrated particulate for solid strengthening and corrosion resistance alloy. This study envisions a snail shell particulate (SSP) as a potential biofillers on aluminium alloy due to its inherent characteristics. The fabrication of the developed alloy was done through liquid stir casting method with determination to examine the correspondent physical, optoelectrical, electrochemical, and microstructural behaviour for chemical application. Composite infringement varies from 10% - 25% SSP after optimization using design of experiment. The result of electrochemical analysis showed a notable decrease in corrosion rate with increased SSP content from 12.06 mm/yr, of control sample to (75Al-25SSP) which had a corrosion rate of 7.59 mm/yr, resulting in a 40.1% drop-in degradation rate. Notably, microhardness properties increase from 28.1 to 45.5 HRB as a result of solid strengthening characteristics of doped fillers. Opto-electrical assessment demonstrated decreasing resistivity with higher SSP content, indicating improved current flow resistance. The microstructural properties showcased SSP's distinctive dispersion with few micro pores. The intermetallic phases confirmed their integration into the metal matrix by providing an enhancing adhesion and solid crystalline structure.