Traditional Casting Techniques Research Articles

Effect of gamma irradiation on properties of the synthesized PANI-Cu nanoparticles assimilated into PS polymer for electromagnetic interference shielding application

Conductive polymer nanocomposites for electromagnetic interference (EMI) shielding are important materials that can be combat the increasingly dangerous radiation pollution arising from electronic equipment and our surrounding environment. In this work, we have synthesized polyaniline-copper nanoparticles (PANI-Cu NPs) by the copper salt based oxidative polymerization method at room temperature and then added with different concentration (0, 1, 3 and 5 wt%) in polystyrene polymer forming PS/ PANI-Cu nanocomposites films by means of the traditional solution casting technique. The formed PANI-Cu NPs were investigated by UV/Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and SEM/EDX elemental mapping techniques. On the other hand, the prepared PS/PANI-Cu nanocomposites films were evaluated by UV and SEM, the mechanical properties of the nanocomposites films were evaluated and showed an improvement by added PANI-Cu NPs up to 3 wt% and 50 kGy gamma exposure dose. The PS/PANI-Cu nanocomposites films were examined as electromagnetic interference shielding material. Electromagnetic shielding effectiveness of the produced nanocomposites were tested in the X-band of the radio frequency range namely from 8 to 12 GHz using the vector network analyzer (VNA) and a proper wave guide. All samples were studied before and after 50 kGy gamma-ray irradiation under the same condition of pressure and temperature. The results showed that the nanocomposites have improved shielding properties.

Jet engine blade: Design, material, and manufacturing

The engine is the most important part of an airplane. Since the blades of an engine are a major factor in jet engine performance, the research of engine blades has always been a hot topic in the field of aerospace. This paper summarizes the research status in the field of jet engine blades. As for the design of the jet engine blade, the design of aerofoil and the geometrical structure of the engine blade is introduced. In the material selection of engine blades, titanium alloy materials, and the application of composite materials are introduced. Electrochemical machining (ECM) and additive technology of engine blades are introduced. The differences between them and traditional casting techniques are compared. The comprehensive analysis shows that the research on engine blades is becoming more and more mature, but there are some challenges in further optimization of manufacturing technology and materials. This paper may offer a reference for the design of jet engine blade.

An Extensive Study and Evaluation of Tribological Properties of Fsw Plates Using Linear Reciprocating Tribometer (LRT)

This study extensively focuses on analyzing the fretting wear characteristics of Aluminum-based hybrid Metal Matrix Composites (MMCs) under dry conditions, essential in understanding materials' tribological properties in mining environments. Aluminum-based MMCs offer improved wear resistance and durability, potentially enhancing mining equipment performance. The investigation targeted Aluminum 7075 alloy-based MMCs, comprising 7% fine greenish Silicon Carbide and 3% chopped E-glass fibers (2-3mm length, 10-14 micrometer diameters). Using traditional stir casting and Friction Stir Welding (FSW) techniques, composite plates meeting ASTM standards were fabricated. FSW parameters like rotation speed and tool feed rate were varied.Analyzing fretting wear on the welded zone, employing different loads through Linear Reciprocating Tribometer (LRT), provided insights into the tribological performance of these Aluminum-based hybrid MMCs. The lightweight and exceptional thermal properties of Aluminum have significantly expanded its use across various industries, enabling partial replacement of ferrous materials, especially in MMCs where Aluminum alloys offer distinct advantages over other materials.This research aids in determining the suitability of these MMCs for demanding mining conditions, where materials endure extreme stress. Understanding their tribological behavior is crucial for potential applications in mining equipment, contributing to longevity and improved performance.

Loss and reintroduction of the radical initiator into the FlexyDos3D silicone dosimeter for 3D printing

3D printers allow for the rapid construction of complex 3D objects that would be very time-consuming with traditional casting techniques. Patient-specific objects have been created for years in the fields of dentistry, prosthetics, and surgical guides. However, 3D printed objects using materials that also serve a functional purpose, biologically or chemically, are now finding bio-medical applications. A custom 3D printer has been made that is able to print the FlexyDos3D silicone dosimeter, but the dosimeter’s sensitivity is severely decreased after printing. Testing was performed to determine if chloroform is lost during printing and techniques were tested to reintroduce chloroform into the dosimeter after printing to improve the dose response of the dosimeter. Results showed that the chloroform was completely evaporated from the dosimeter when exposed to conditions similar to that during printing and that chloroform could be reintroduced by soaking or exposure to chloroform vapours which led to an increase in the dose sensitivity. Further testing of the reintroduction of chloroform into the dosimeter is ongoing.

Nanoscale microstructures and hydrogenation properties of an as-cast vanadium-based medium-entropy alloy

Vanadium-based hydrogen storage alloys have been widely investigated; however, alloys in the cast state are typically coarse-grained. In this study, an as-cast V45Fe15Ti20Cr20 medium-entropy alloy was prepared by arc melting, and microstructural analysis revealed that the alloy was composed of nanocrystals. The initial pretreatment temperature of the alloy was approximately 100 K lower than that of the as-cast coarse-grained alloy. At room temperature, the time required for the alloy to reach 90% saturation was only 140 s, indicating excellent hydrogen absorption kinetics. The alloy is fully activated after two hydrogen absorption/desorption cycles. The phase transformation of the alloy in the early hydrogenation stage was investigated using X-ray diffraction, and the results showed that the BCC phase was completely transformed into the BCT phase when hydrogen uptake was performed for 6 s. Furthermore, the apparent activation energy of dehydrogenation in the present alloy calculated using the Kissinger method was 69.8 ± 0.8 kJ/mol. The pressure-composition-isotherms tests showed that the hydrogen absorption capacity of the alloy at 295 K was 2.12 wt%. The hydrogenation/dehydrogenation enthalpy change of the alloy was calculated by the Van't Hoff equation, which was 30.90 ± 1.47 and 33.95 ± 0.41 kJ/mol, respectively. The present work demonstrates that nanostructured vanadium-based hydrogen storage alloys can be fabricated using traditional casting techniques. Our study also enriches the understanding of the microstructures of medium-entropy alloys, which may provide positive guidance for the design of novel vanadium-based hydrogen storage alloys.

Metal Matrix Alloy AA 6061 Produced by Stir Casting Method

Abstract. In compared to base alloy, aluminum composites made from the AA6061 alloy perform better and have better material properties. The current work provides a thorough analysis of the AA 6061 metal matrix composite (MMC) produced using a traditional stir casting technique. Process parameters and characterization techniques have both been discussed. Upon review, it was found that the most often employed reinforcements for the production of AA 6061 metal matrix nano composite (MMNC) were Al2O3, B4C, SiC, and TiC. Other acceptable reinforcements, such as hybrid, inorganic, nanomaterial, and organic reinforcements, are being considered in the current trend. The AA 6061 hybrid composites have comparable superior qualities to single component composites because they contain two or more reinforcements. There is a tonne of room for AA study. Research on the AA 6061 nanocomposite, which has significantly higher strength and wear resistance and is suitable for aerospace and defence applications, has a lot of potential.

Structure and optoelectronic properties of ferroelectric PVA-PZT nanocomposites

PbZr0.8Ti0.2O3 lead zirconate-titanate was prepared using the tartrate precursor method, and (Polyvinyl alcohol (PVA)/PbZr0.8Ti0.2O3 (PZT)) thin films systems were designed by the traditional casting technique. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods were used to investigate the effect of the annealing temperature of PZT on the structural characteristics of the prepared composite films. PZT was annealed at various temperatures (600 °C, 700 °C, 800 °C, 900 °C, 1000 °C, and 1100 °C), and X-ray examination indicated that it included rhombohedral and tetragonal perovskite structures. Moreover, the effect of the annealing temperature on the optical band gaps, refractive index, extinction coefficient, and optical conductivity of the samples was studied using the UV–VIS spectrophotometer technique. The photoluminescence (PL) technique showed that the studied PVA/PZT films illustrated three spectra for all the samples. The Raman spectra evaluated five major Raman modes (A1(1TO), E(2TO), E (3TO+2LO)+B1, E(3TO), and A1(3LO), and T2g, which are expected in the perovskite structure. This study showed that adding PZT to the PVA matrix leads to changes in the morphological and structural properties, and the direct and indirect energy band gap (Eg) was decreased. We consider that the clustering effect in our samples increases as the crystallite size increases and prevents the vibration of the C–H bond, resulting in the disappearance of this bond in the Raman spectra. The formation of defects in synthesized compounds was analyzed using PL spectra. This system's compositional (the studied samples) dependency on optical properties makes it appropriate for optoelectronic applications.

Differences between the Fittings of Dental Prostheses Produced by CAD-CAM and Laser Sintering Processes.

Digital dentistry and new techniques for the dental protheses' suprastructure fabrication have undergone a great evolution in recent years, revolutionizing the quality of dental prostheses. The aim of this work is to determine whether the best horizontal marginal fit is provided by the CAD-CAM technique or by laser sintering. These values have been compared with the traditional casting technique. A total of 30 CAD-CAM models, 30 laser sintering models, and 10 casting models (as control) were fabricated. The structures realized with chromium-cobalt (CrCo) have been made by six different companies, always with the same model. Scanning electron microscopy with a high-precision image analysis system was used, and 10,000 measurements were taken for each model on the gingival (external) and palatal (internal) side. Thus, a total of 1,400,000 images were measured. It was determined that the CAD-CAM technique is the one that allows the best adjustments in the manufacturing methods studied. The laser sintering technique presents less adjustment, showing the presence of porosities and volume contraction defects due to solidification processes and heterogeneities in the chemical composition (coring). The technique with the worst adjustments is the casting technique, containing numerous defects in the suprastructure. The statistical analysis of results reflected the presence of statistically significant gap differences between the three manufacturing methods analyzed (p < 0.05), with the samples manufactured by CAD-CAM and by traditional casting processes being the ones that showed lower and higher values, respectively. No statistically significant differences in fit were observed between the palatal and gingival fit values, regardless of the manufacturing method used. No statistically significant differences in adjustment between the different manufacturing centers were found, regardless of the process used.

Performance of Fuel Electrode-Supported Tubular Protonic Ceramic Cells Prepared through Slip Casting and Dip-Coating Methods

Fuel electrode-supported tubular protonic ceramic cells (FETPCCs) based on the BaZr0.4Ce0.4Y0.15Zn0.05O3−δ (BZCYZ) membrane electrolyte was fabricated through a two-step method, in which the polyporous electrode-support tube was prepared with a traditional slip casting technique in a plaster mold, and the BZCYZ membrane was produced by a dip-coating process on the outside surface of the electrode-support tube. The dense thin-film electrolyte of BZCYZ with a thickness of ~25 μm was achieved by cofiring the fuel electrode support and electrolyte membrane at 1450 °C for 6 h. The electrochemical performances of the FETPCCs were tested under different solid oxide cell modes. In protonic ceramic fuel cell (PCFC) mode, the peak power densities of the cell reached 151–191 mW·cm−2 at 550–700 °C and exhibited relatively stable performance during continuous operation over 100 h at 650 °C. It was found that the major influence on the performance of tubular PCFC was the resistance and cathode current collectors. Additionally, in protonic ceramic electrolysis cell (PCEC) mode, the current densities of 418–654 mA·cm−2 were obtained at 600–700 °C with the applied voltage of 2.0 V when exposed to 20% CO2–80% H2 and 3% H2O/air. Using distribution of relaxation time analysis, the electrolytic rate-limiting step of the PCEC model was determined as the adsorption and dissociation of the gas on the electrode surface.

Ambilateral convergent directional freeze casting meta-structured foams with a negative Poisson’s ratio for high-performance piezoresistive sensors

Flexible piezoresistive sensors show broad application value in wearable electronic skin, health monitoring and motion detection. The practical range of conventional piezoresistive sensors, however, is often severely limited by their sensitivity, measuring span, mechanical properties, and lateral expansion caused by positive Poisson's ratio (PPR) effects. Herein we introduce a generally applicable methodology, ambilateral convergent directional freeze casting technique, for the fabrication of anisotropic porous foams with a negative Poisson's ratio (NPR). Different from traditional freeze casting technique, this new design methodology enables precise control of pore types and pore orientations, thereby endowing artificial materials with special mechanical properties. Under uniaxial compression, synthetic foams exhibit macroscopic lateral shrinkage, with a Poisson's ratio below – 4.2% at the strain of 25%. These conductive meta-structured foams are used to construct piezoresistive sensors. Compared with traditional structures, metastructures with NPR effects significantly increase the number of wall-to-wall contacts and the formation of electrical paths, thereby enhancing the sensitivity and sensing reliability of sensors. In addition, the NPR effect markedly enhances the mechanical elasticity and compression resistance of sensors, enabling it to have excellent signal stability even in the face of reiterative compressions. These meta-structured sensors also exhibited smart resistivity repair behavior in the face of overload damage. Integrated sensors can be used for monitoring of pressure distribution and athlete's gait. Lateral contractions caused by NPR effects can avoid the contact of adjacent sensors and narrow the gap between two sensors, thus improving sensing stability and pressure distribution resolution of distributed sensors.

Evaluation of margin and internal fit of full arch metal coping fabricated using computer aided milling, direct laser sintering, and traditional casting technique

Evaluation of margin and internal fit of full arch metal coping fabricated using computer aided milling, direct laser sintering, and traditional casting technique

Investment Casting Using FDM 3-D Printing

Abstract: The earliest casting method is investment casting, which dates back to roughly 3500 BC. Precision casting and near net form are two applications. Product demand is increasing in India and around the world. The use of simulation and rapid prototyping techniques in the investment casting process improves quality while reducing lead time and cost. However, as complexity increases, the traditional sand casting technique has limits, one of which is the expensive expense of equipment to make moulds and cores. These limitations can be solved by using a 3D printer, which offers the distinct advantage of geometric freedom. A polycast design is created in the precise shape of the item to be cast in this project. A refractory ceramic substance has been applied to this pattern. The metal is flown through a mould that is linked to the tree. The accuracy and surface finish of the models and castings were also assessed in order to provide a comparison. It has a significant impact on part quality (surface finish, dimensional correctness, strength, and longevity), as well as lead time and cost. In terms of remote pattern manufacture, it offers a lot of potential

A Study on the Recreated Experiment and Casting Method of Ancient Iron Seated Buddha by Spilt Casting Method

The study aimed to investigate the split casting method based on the recreation of the iron-seated Buddha (ISB) statue (number 1971) in the Chuncheon Museum. The statue was designed using three-dimensional scan data and reduced to half-size. Using the existing research results, the ISB statue was created by mold production and split casting. The mold was prepared by mixing sand and clay at a ratio of 3:4 and 1:3 on the outside and inside, respectively, and then casting was done. Various casting defects were observed in the ISB casting and similar shapes were seen. The casting defects included veining or finning, misrun, open or external shrinkage, surface or subsurface blowholes, surface pinholes, and shift. The microstructures were identified as branch-shaped dendrite and pearlite organizations, and black graphite was observed between the cementite organizations. The study findings may be relevant in exploring traditional casting and manufacturing techniques of ISB and may aid in the production of the original form of ISB.

Investigations on noise emission from functionally graded materials based polymer spur gears

There is tremendous growth in the polymer gearing field. Polymer gears have replaced the metal gears in various fields. Polymer gears are now used for low, medium, and even for high power transmission systems, especially in automotive engineering. Noise emission from polymer gears is much less than metal gears in an application. In the present work, homogeneous and functionally graded materials (FGMs) gears are fabricated by glass fiber reinforced high-density polyethylene (HDPE) material via traditional and centrifugal casting techniques, respectively. Gears are manufactured by HDPE granules reinforced with fifteen weight percent and thirty weight percent of glass fibers. The focus of this experimental study is to examine the noise generation from the fabricated gears during the operation. Fabricated gears are run for 2 lakh cycles at different speeds and torque. The value of torque and speed are chosen within the range of 0.8–2.6 Nm and 500–1400 rpm, respectively. Experiments are performed on the polymer gear test rig. Noise emission from fabricated polymer gears is investigated for various running combinations of torque and speed.

Surface integrity in drilling AA5052 + 3 %MoS2 + 9 %Si3N4 HAMMC and comparing the results with AA5052 + 9 %Si3N4 AMMC - experimental studies and optimization

The purpose of this study is to compare the surface roughness (SR) achieved during drilling the fabricated aluminium metal matrix composite (AMMC) considering AA5052 as base matrix and 9 % silicon nitride (Si3N4) ceramic as reinforcing phase with hybrid aluminium metal matrix composite (HAMMC) added with 3 % of solid lubricant MoS2 (AA5052 + 3 %MoS2 + 9 %Si3N4) using carbide drill bit. The novel AMMC and HAMMC are fabricated by the traditional liquid casting technique. For investigation of the drilling process two groups were selected: an experimental group (AA5052 + 3 %MoS2 + 9 %Si3N4) and control group (AA5052 + 9 %Si3N4). Based on the sample size calculator, 20 samples were considered for each group for performance comparison. A CNC vertical machining center was adopted for performing the drilling process with a carbide drill bit without the application of coolant which is termed as green machining. From the outcomes of this research work it is identified that with the inclusion of solid lubricant MoS2, surface roughness is reduced because of friction reduction among workpiece and drill bit. The mean value of SR for the experimental group is 0.806 μm whereas for the control group it is 1.281 μm. During statistical analysis with Independent sample T-test, significance obtained is 0.008 which is below the ideal value of p < 0.05. Hence a significant variance exists among the considered groups. Within the limit of this study it is identified that AA5052 + 3 %MoS2 + 9 %Si3N4 developed superior surface finish during the machining process because of the inclusion of solid lubricant MoS2 against the fabricated AMMC.

Structural, transport, morphological, and thermal studies of nano barium titanate–incorporated magnesium ion conducting solid polymer electrolytes

A new series of nanocomposite polymer electrolytes (NCPEs) was prepared using poly(vinylidene fluoride–co–hexafluoro propylene) P(VdF-HFP) as polymer, magnesium triflate (MgTr) as salt and nano-sized barium titanate (BaTiO3) (&lt;100 nm) as nanofiller via traditional solution casting technique. Decrease in crystalline nature of the samples due to the incorporation of nano BaTiO3 was revealed through X-ray diffraction (XRD) analysis. From AC impedance spectroscopy, maximum conductivity of 4.11 × 10−4 Scm−1 was attained for the addition of 6 wt% of nano BaTiO3 to the P(VdF-HFP)/MgTr matrix. Dielectric studies were found to be in accordance with the ionic conductivity studies. For the most highly conducting sample, a greater number of mountain valley pattern was observed from Atomic Force Microscopy (AFM) analysis. Thermal stability of the sample, P(VdF-HFP)/MgTr/BaTiO3 (6 wt%) (which possessed maximum ionic conductivity) was observed through TG/differential thermal analysis studies. All these results suggested that these materials are favorable and find application in practical electrochemical devices.

Synthesis and Physicochemical Studies of Polyvinyl Alcohol Polymer Modified with Copper Thiosemicarbazide Complex

Thiosemicarbazones (TSCs) represent a category of chemical compounds that attract diverse research groups' attention due to their wide and extended applications in different pharmaceutical and agrochemical applications. Complexation reactions between the ligand and CuCl2 resulted in the formation of [Cu2(H2MTS)Cl2(H2O)4 ]. X-ray diffraction data analysis of the studied complex suggests octahedral structure, while characterization through elemental, thermal, magnetic, and spectral (UV, IR, NMR, and ESR) analyses showed the formation of the complex. Thin films of pure polyvinyl alcohol and other samples containing different mass fractions of CuTSCs were successfully prepared through the traditional solution casting technique. Studies of the synthesized thin films show a notable change of crystallinity, optical band gap, refractive index, dielectric primitivity, and other physical properties with increasing copper complex. Besides, synthesized samples show an observed activity against different pathogenic grams. Increasing copper complex content also shows a prominent change in different samples' swelling rates, suggesting that metal complex acts as a controlled cross-linker for polyvinyl alcohol (PVA) polymer.

Structural and optical properties of PEO/CMC polymer blend modified with gold nanoparticles synthesized by laser ablation in water

Eco-friendly and cost-effective route using water were employed for the synthesis of gold nanoparticles (AuNP's) via laser ablation technique. Formation of AuNP's were observed through the appearance of surface plasmon resonance (SPR) peak originally located at 520 nm within the UV/Visible spectrum of synthesized sample and approved with Transmission electron microscope (TEM). X-ray diffraction analysis and TEM micrograph shows the formation of fcc crystal structure of nano-sized gold with a diameter ranging between 10 and 25 nm. Virgin samples of polyethylene oxide (PEO) and carboxymethyl cellulose (CMC) in combination with their 50/50wt% blend films were synthesized via traditional solution casting techniques. Besides other samples of blend films containing a variable amount of gold nanoparticles (AuNPs) within the doping level. Different characterization techniques were employed to study the composite thin film structure. X-ray diffraction pattern reveals a barely noticed increase of the amorphous nature with increasing gold content. FTIR suggests the formation of hydrogen bonding within the composite matrix with an appearance of the characteristic vibrational groups of the constituting matrices regardless of the content of dopant AuNP's. UV/Visible electronic spectra reveal a notable change within the optical energy gap in comparison with the pristine samples attributed to the introduced dopant.

Direct Ink Writing of Moldable Electrochemical Energy Storage Devices: Ongoing Progress, Challenges, and Prospects

Among the advanced additive manufacturing technologies, direct ink writing (DIW) technology is extensively utilized to fabricate various energy storage devices (i.e., batteries, supercapacitors [SCs], and solar cells) due to its excellent process flexibility, excellent geometric controllability, as well as relative low‐cost and efficient processes. DIW offers a convenient way to build 3D structures for energy storage devices and provide higher power density and energy density in comparison with traditional casting techniques. Herein, the recent advances in DIW for emerging energy storage devices, including SCs, lithium‐ion batteries, lithium–sulfur batteries, rechargeable lithium metal batteries, and solid‐state batteries, are emphasized and discussed. The significant achievements made developing printed energy storage devices, such as printing ink materials, designing the printing process, and the great progress in terms of the corresponding electrochemical performances, are also highlighted. Finally, the major challenges and potential research possibilities in 3D printing energy storage device are proposed. It can be expected that, as 3D printing technology develops, batteries and SCs with durable lifespans, favorable safety, as well as high energy density and power density will eventually be utilized in many fields.

Corn Starch (Zea mays) Biopolymer Plastic Reaction in Combination with Sorbitol and Glycerol.

The research included corn starch (CS) films using sorbitol (S), glycerol (G), and their combination (SG) as plasticizers at 30, 45, and 60 wt %, with a traditional solution casting technique. The introduction of plasticizer to CS film-forming solutions led to solving the fragility and brittleness of CS films. The increased concentration of plasticizers contributed to an improvement in film thickness, weight, and humidity. Conversely, plasticized films reduced their density and water absorption, with increasing plasticizer concentrations. The increase in the amount of the plasticizer from 30 to 60% showed a lower impact on the moisture content and water absorption of S-plasticized films. The S30-plasticized films also showed outstanding mechanical properties with 13.62 MPa and 495.97 MPa, for tensile stress and tensile modulus, respectively. Glycerol and-sorbitol/glycerol plasticizer (G and SG) films showed higher moisture content and water absorption relative to S-plasticized films. This study has shown that the amount and type of plasticizers significantly affect the appearances, physical, morphological, and mechanical properties of the corn starch biopolymer plastic.