Metallurgical and Materials Engineering (E-Journal)
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Investigation of material removal rate and surface roughness during electrical discharge machining on Al (6061)-5%SiC-10%B4C hybrid composite
Get PDFElectrode Discharge Mechanism (EDM) is a manufacturing process using controlled sparks that occur between an electrically conductive workpiece and an electrode in the presence of an insulating liquid. The EDM process is commonly used to manufacture metallic matrix compounds that have wide applications in the railway sectors and the aircraft industry. Aluminum metal matrix composites (AMMCs) are one of the important kinds of metallic matrix compounds due to their advanced characteristics, such as lightweight and high strength. This lightweight material was developed and used in various manufacturing processes, like the automobile industry to reduce vehicle weight and thus reduce fuel consumption. This paper discussed the experiments of the EDM that were conducted to examine the effect of machining parameters, including peak current (10, 20, and 30 A), pulse on different times (50, 100, and 200 µsec), duty factors (4, 6, and 8) on the material removal rate, and surface roughness of the Al (6061)-5%SiC-10%B4C hybrid composite as workpiece using copper electrode tool by Box-Behnken design. The analysis data for the dependent and independent variables manifested that the influence of machine parameters whenever Ip and Pon increase, the MRR and Ra increase.
Effect of copper-graphite composite electrode on material removal rate and surface roughness in MONEL 400 during electrical discharge machining
Get PDFElectrical Discharge Machining (EDM) is one of the non-traditional machining processes commonly used for machining of hard to cut metals. Monel 400 is a nickel based superalloy used in various applications. The composite electrode is developed and applied to enhance the machining process by reducing the time of the process and the cost of the electrode manufacturing. The presented work is aimed to study the effect of copper, graphite, and copper-graphite composite electrodes with different parameters on the Material Removal Rate and Surface Roughness of Monel 400. Influences of discharge current (Ip), pulse on time (Ton), and pulse off time (Toff) have been investigated. Based on the Taguchi method, experiments were analyzed using ANOVA through Minitab 20. The results have manifested that compared to copper and graphite electrodes, the copper-graphite electrode achieved better values of material removal rate and surface roughness. The lowest value of surface roughness is 3.1413 μm as a result of the added graphite reinforcement particles.
Synthesis and characterization of biocomposites based polypropylene/thermoplastic starch- reinforced with natural STIPA TENACISSIMA fibers and PP-g-MA
Get PDFThe current work aims to develop environmentally friendly plastic materials by preparing a composite polypropylene/thermoplastic starch (PP/TPS) using a melt-compounding process. In order to improve the compatibility of the two naturally incompatible polymers, natural Stipa tenacissima fibers treated on their surfaces and polypropylene (PP) pellets grafted with Maleic Anhydride (MA) were added to the mixture (PP and TPS). The mixture was then prepared using the melt-mixing method in various concentrations. X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA)/Differential thermal analysis (DTA), and mechanical tensile tests were then used to characterize the various formulations. SEM images revealed that the addition of (PP-g-MA) and natural fibers resulted in good starch plasticization and higher thermoplastic starch dispersion in the polypropylene matrix. It was also discovered that increasing the TPS concentration over the PP concentration tends to reduce the mechanical tensile properties. However, the composite with 15% TPS had the best mechanical properties. The thermogravimetric analysis (TGA) results revealed that the organic filler used acted as a reinforcing agent, increasing the thermal stability of the polypropylene/thermoplastic starch (PP/TPS) compound
Sustainable development in WPCBs treatment for production of bituminous waterproofing materials
Get PDFDue to the rapidly increasing use of electrical devices, e-waste became one of the major threats to the environment. Waste printed circuit boards (WPCBs) are an integral part of electrical devices, thus the interest in their recycling is growing. Recycling of WPCBs can be performed by applying hydrometallurgical or pyrometallurgical processes, as well as vacuum pyrolysis. The main advantages of vacuum pyrolysis are eco-friendliness, economic viability and efficiency in extracting present noble metals, while pyrolysis oil occurs as a by-product. Pyrolysis oil poses a tremendous threat to the environment, due to the possibility of its spillage into water, as well as a potential release into the air and soil. Because of this, the pyrolysis oil was subjected to chemical treatment with different reagents, such as sodium hydroxide, calcium oxide, sulfuric acid and maleic anhydride, with the intent to solidify the material and remove unpleasant odors. Incorporation of the solidified materials into bitumen, at 2.5, 5, 7.5, and 10 wt.% addition, was performed to obtain waterproofing materials. The obtained solidified and bituminous water-resistant materials were subjected to various test methods: FTIR spectroscopy, physicochemical and mechanical properties of bitumen, etc. which showed that all the tested characteristics are in accordance with values prescribed by the current standard. Toxicity Leaching Procedure (TCLP) confirmed non-hazardous characteristics of the obtained materials, except for the ones with added solidified pyrolysis oil, with Sodium hydroxide, that showed higher leaching of the phenol constituent
Dry sliding wear behavior and its relation to microstructure of artificially aged Al-Si-Mg/TiB2 in situ composites
Get PDFMechanical stir casting is utilized to produce an artificially aged Al-Si-Mg alloy, whereas halide slat (K2TiF6 and KBF4) synthesis is utilized to produce Al-Si-Mg/TiB2 aluminum matrix composites. The dry sliding pin on disc wear test was conducted using a DUCOM/TR-20LE-PHM-200 machine to simulate an automobile application (Piston-Ring assembly). Where pistons are made of aluminum alloy (for the Pin) and rings are made of grey cast iron (for the disc material). At room temperature, a wear test was conducted by altering the ageing time (3, 6, 9, 12), sliding speed (2, 2.5 m/s), and applied load (14.71, 19.62, 24.52 N) with the disc speed (500 rpm) held constant (10 min). The results indicate that the aluminum matrix composite (AMC) wear rate is reduced by 37 percent at higher sliding speeds (2.5 m/s) and by 4 percent at lower sliding speeds (2.0 m/s) compared to the base alloy. Field emission scanning electron microscope-energy dispersive spectroscopy (FESEM-EDS) and X-ray photoelectron spectroscopy (XPS) analysis revealed that the formation of the mechanically mixed layer (MML) or oxidative layers on the worn surfaces reduces the wear rate under conditions of longer ageing time, higher sliding speed, and lower applied load. The research demonstrates that composite wear is a function of sliding velocity, aging period, and applied force. As sliding speed rose from 2 m/s to 2.5 m/s, the wear rate of composites dropped reasonably, yet composites are softer than basic alloys. It is conceivable due to the presence of a considerable amount of MML and the formation of oxidative layers between pins and their equivalents
The effect of microwave energy on sintering of an austenitic stainless steel reinforced with boron carbide
Get PDFMicrowave heating has emerged as an alternative to traditional sintering methods because it consumes less energy and requires shorter processing times. The use of microwave energy in the processing of austenitic stainless steel AISI 316L reinforced with dispersed boron carbide particles was investigated in this study. Different processing parameters were used to investigate the effect of sintering time and temperature, as well as the weight percentage of the ceramic added to the steel matrix, on the final material properties. The compressibility curve, elastic relaxation, and geometric density of green compacts were used to investigate their physical properties. The Archimedes method was used to determine density, and the statistical treatment of analysis of variance was used to determine porosity. Images obtained using optical microscopy and scanning electron microscopy revealed the formation of a second phase in different volumes. The results showed that 1100 °C and a 15-minute plateau were sufficient to sinter the material. AISI 316L samples containing 3 wt.% boron carbide demonstrated greater volumetric formation of secondary phases, resulting in a significant increase in the hardness of the austenitic composite developed
Water hyacinth (EichhorniaCrassipes) polymer composites properties - aquatic waste into successful commercial product
Get PDFIn modern times, the demand for natural fibers is increased due to low density, low cost, recyclability, and biodegradable properties. Following work deals with the aquatic waste of water hyacinth plant fiber. The main intent of this work is to utilize the hyacinth plant into a successive manner and convert this plant into some commercial products. It is used as reinforcement material and epoxy polymer resin in matrix material with a suitable percentage of hardener (10:1). A new method such as a mechanical way of extraction process is introduced in this work. The different weight percentage of the hyacinth fiber is reinforced with matrix material like 15, 20, 25, 30, and 35%. With the help of a compression molding, machine water hyacinth reinforced fiber composite is produced by using 1500 PSI pressure and 110 °C, 100 °C of upper and lower plate temperature. A composite sample is cut into as per ASTM standards and the mechanical tests like tensile, flexural, impact test is conducted by using universal testing machine (UTM), and Charpy impact test machine. Based on the final mechanical test results, the 30% of hyacinth composite sample tensile 36.48 MPa, flexural 48.62 MPa, impact 0.5 J, and hardness 98 attained then, the hyacinth composite samples are adopted into water and chemical absorption test with 10 hours, 1week, 1month of continuous monitoring. Based on the final results, hyacinth fiber is strongly recommended to use an alternative of synthetic fibers and conventional natural fibers. The hyacinth composite is strongly recommended for the usage of commercial and household applications
Circular economy implementation in the development of fire-retardant materials used in construction, industry, and general-purpose products
Get PDFDuring a fire, passive fire protection systems are designed to prevent the spread of flames, smoke, and toxic gases. The new fire-retardant (FR) material, used for passive fire protection, is created by combining copolymers (VC–co–VAc) (Slovinyl KV 173) and PVC K70 with expanded graphite and plasticizers/modifiers such as diisononyl phthalate - DINP, diisononyl terephthalate - DINTP, dioctyl adipate - DOA, as well as plasticizers that are synthesized based on tertiary recycling of waste poly(ethylene terephthalate) (PET), 1-hexadecene, azodicarbonamide (ADC), tri(p-cresyl phosphate), epoxidized soybean oil (ESO) and acrylate emulsion (DH50, Ecrylic, or Flexryl, etc.). The obtained material's morphology was examined using an emission scanning electron microscope (FESEM) field. Tensile testing was used to determine the mechanical properties of the obtained samples, as well as Shore A hardness and toughness using the Charpy impact test. All samples obtained were tested according to non-flammability standards. To conform to the new trend of "green economy," the development of novel eco-friendly FRs with improved thermal and mechanical properties will include careful consideration of environmental protection and sustainable development
Thermal transport properties and microstructure of the solid Bi-Cu alloys
Get PDFThermal transport properties of solid Bi-Cu alloys have been investigated over a wide composition range and temperature range between 25 and 250 °C. The flash method was used to determine thermal diffusivity. Thermal diffusivity was discovered to decrease continuously with increasing temperature and bismuth content. The indirect Archimedean method was used to determine the density of the Bi-Cu alloys at 25 °C. The obtained results show that the density of the studied alloys decreases slightly as the copper content increases. Thermal conductivity of the alloys was calculated using measured diffusivity, density, and a calculated specific heat capacity. The thermal conductivity of the studied Bi-Cu alloys decreases with increasing temperature and bismuth content, similar to thermal diffusivity. SEM with energy dispersive X-ray spectrometry (EDS) and differential scanning calorimetry (DSC) were used to examine the microstructure and melting behavior of Bi-Cu alloys, respectively. The eutectic temperature was measured to be 269.9±0.1 °C, and the measured phase transition temperatures and heat effects were compared to the results of CALPHAD thermodynamic calculations
Deformation behavior and processing map of ATI 425 with initial lamellar microstructure
Get PDFThe effect of hot compression temperatures and strain rates on deformation behavior and resultant microstructure of ATI 425 alloy with initial lamellar microstructure was investigated in this study. The temperature and strain rate of the hot compression test were chosen to be in the 700-1100 °C and 0.001-1 s-1 ranges, respectively. The stress-strain curve and microstructure evaluation show that the alloy's flow softening is associated with globularization and dynamic recrystallization mechanisms. The constitutive equation calculates the activation energy for the α/β and β regions to be 348 kJ/mol and 201 kJ/mol, respectively. Dynamic recovery and partial recrystallization are the dominant structure modification mechanisms in the beta single-phase region. Bending and fragmentation of alpha plates is the dominant mechanism of microstructure promotion in the α/β region at low temperatures and low strain rates, less than 0.1s-1. Local shear and alpha plate break-up are the main factors in structural modification at high strain rates, greater than 0.1s-1. The extracted process map at 0.5 strain revealed three zones: instability, safe zone, and peak zone, with power dissipation efficiencies of 0 -0.25%, 30-40%, and above 40%