Browse Topic: Microscopy

Items (664)
When a train passes continuously over a section of the track, the track gradually moves away from the intended vertical and horizontal alignment with time and repeated use. Regular maintenance on the track, such as leveling, lifting, lining, and tamping, is necessary to maintain the optimal geometry of the track. Ballast is leveled and squeezed by hydraulic rams in tamping machines. The tamping is a process of ballast packing under railway tracks. In current system a set of tungsten carbide chips are attached either by welding or by coating on tamping tool tip made of EN24 steels. These tungsten carbide chips directly come in contact with the ballasts. After few tamping works, gradually these chips torn out and need to be replaced after certain period. Tungsten carbide is a costly material, therefore this research deals with replacement of tungsten carbide with silicon carbide (easily available cheaper) coating used for tamping tools tip. The study consists of microstructural
Mishra, MamtaPandey, ManasSingh, ShrutiSrivastava, SanjayKumar, Jitendra
Innovators at NASA Johnson Space Center have developed a handheld digital microscope to fill the critical microscopy needs of human space exploration by providing flight crews in situ hematological diagnostic and tracking ability to assess and monitor crew health in the absence of gravity. Although currently in use aboard the International Space Station (ISS) to work in conjunction with NASA’s handheld slide staining system, the microscope may have numerous applications here on Earth.
The efficiency and performance of lithium-ion batteries are highly influenced by the quality of laser cutting of electrode materials. The laser cut quality of thin foils is often measured by amount of kerf width and heat-affected zone (HAZ). This article adopts a novel approach that involves pre-cooling of thin copper foils prior to the laser cutting process. The impact of laser conditions and foil temperature were analyzed on HAZ and kerf width induced during laser cutting experiments conducted based on L27 orthogonal array. Teaching–learning–based optimization (TLBO) technique was employed to identify the optimal laser parameters. ANOVA results indicated that the temperature was the most significant factor influencing kerf width and HAZ. The optimized laser parameters identified through TLBO technique were 16 W laser power, 69.47 mm/s scanning speed, and 20 kHz pulse frequency at dry ice conditions. A reduction of 50.76% kerf width and a decrease in 7.6% HAZ were observed when the
Rao, Akshay P.Bharatish, A.Solaiachari, SivakumarKumar, S. Mahendra
Platinum (Pt), palladium (Pd), and rhodium (Rh) are used as active substances in exhaust gas purification catalysts for automobiles. Among these, Rh is an essential element because it efficiently promotes a NOx reduction reaction. On the other hand, the price of Rh has been rising in recent years. From the perspective of the supply risk of rare resources, there is an urgent need to develop technologies to replace or reduce the amount of Rh used in catalysts. We focused on the pseudo-rhodium alloy developed by the ACCEL program of the Japan Science and Technology Agency (JST), and then investigated the application of the pseudo-rhodium alloy on the catalysts of our motorcycles and also the degradation process. A nanosized PdRuIr alloy supported on a ceria-zirconia solid solution (PdRuIr/CZ) was prepared and assembled into a motorcycle for emissions measurement. The PdRuIr/CZ catalyst with an alloy loading of 4.0 g/L had initial properties comparable to the Rh supported on a CZ (Rh/CZ
Motegi, TakuyaTatara, ShunyaTakamoto, ShunpeiDoi, Kosuke
Mechanical analysis was performed of a non-pneumatic tire, specifically a Michelin Tweel size 18x8.5N10, that can be used up to a speed of 40 km/h. A Parylene-C coating was added to the rubber spoke specimens before performing both microscopic imaging and cyclic tensile testing. Initially, standard ASTM D412 specimens type C and A were cut from the wheel spokes, and then the specimens were subjected to deposition of a nanomaterial. The surfaces of the specimens were prepared in different ways to examine the influence on the material behavior including the stiffness and hysteresis. Microscopic imaging was performed to qualitatively compare the surfaces of the coated and uncoated specimens. Both coated and uncoated spoke specimens of each standard type were then subjected to low-rate cyclic tensile tests up to 500% strain. The results showed that the Parylene-C coating did not affect the maximum stress in the specimens, but did increase the residual strain. Type C specimens also had a
Collings, WilliamLi, ChengzhiSchwarz, JacksonLakhtakia, AkhleshBakis, CharlesEl-Sayegh, ZeinabEl-Gindy, Moustafa
This study investigates the ignitability of hydrogen in an optical heavy-duty SI engine. While the ignition energy of hydrogen is exceptionally low, the high load and lean mixtures used in heavy-duty hydrogen engines lead to a high gas density, resulting in a much higher breakdown voltage than in light-duty SI engines. Spark plug wear is a concern, so there is a need to minimise the spark energy while maintaining combustion stability, even at challenging conditions for ignition. This work consists of a two-stage experimental study performed in an optical engine. In the first part, we mapped the combustion stability and frequency of misfires with two different ignition systems: a DC inductive discharge ignition system, and a closed-loop controlled capacitive AC system. The equivalence ratio and dwell time were varied for the inductive system while the capacitive system instead varied spark duration and spark current in addition to equivalence ratio. A key finding was that spark energy
Hallstadius, PeterSaha, AnupamSridhara, AravindAndersson, Öivind
The tensile and low-cycle fatigue (LCF) properties of Ti6Al4V specimens, manufactured using the selective laser melting (SLM) additive manufacturing (AM) process and subsequently heat-treated in argon, were investigated at elevated temperatures. Specifically, fully reversed strain-controlled tests were performed at 400°C to determine the strain-life response of the material over a range of strain amplitudes of industrial interest. Fatigue test results from this work are compared to those found in the literature for both AM and wrought Ti6Al4V. The LCF response of the material tested here is in-family with the AM data found in the literature. Scanning electron microscopy performed on the fracture surfaces indicate a marked increase in secondary cracking (crack branching) as a function of increased plastic deformation and demonstrating equivalent performance when compared to the wrought Ti6AL4V at RT (room temperature) at 1.4% strain amplitude and better performance when compared to the
Gadwal, Narendra KumarBarkey, Mark E.Hagan, ZachAmaro, RobertMcDuffie, Jason G.
In an attempt to improve its mechanical characteristics in the as-fasted conditions, the AZ31 Mg alloy was investigated herein from being reinforced with diverse SiC weight percentages (3, 6, and 9 wt.%). To develop lightweight AZ31-SiC composites, a simple and inexpensive technique, the stir casting process, was used. Microstructural analysis of the as-cast samples showed that the SiC particles were distributed rather uniformly, were firmly bonded to the matrix, and had very little porosity. The substantial improvement in tensile, compressive, and hardness characteristics was caused by fragmentation and spreading of the Mg17Al12 phase, while the addition of SiC had only a slight effect on the microstructure in the as-cast state. Surfaces of AZ31-SiC composites were analyzed using scanning electron microscopy. A study identified the AZ31-SiC composite as a unique material for applications involving a high compressive strength, such as those found in the aviation and automobile
Thillikkani, S.Kumar, N. MathanFrancis Luther King, M.Soundararajan, R.Kannan, S.
This study investigates the heat transfer properties of graphene nanoplatelets (GnPs) blended with distilled water-ethylene glycol (DW-EG) mixtures, focusing on their potential application in battery thermal management systems (BTMS). Compared to other nanoparticles, carbon nanostructures exhibit higher thermal conductivity due to their low density and integrated thermal conductivity. The experimental findings are relevant in that compared with the base fluid, nanofluid samples had heat transfer capability. The physicochemical characteristics of investigated GNP were characterized using a Scanning Electron Microscope (SEM), pH and UV–Vis spectrophotometry. The thermal conductivity and physical properties of graphene platelets having the specific surface area of 500 m2/g in the base fluid of Distilled Water-Ethylene Glycol (DW-EG 70:30) and 100 % vol. of Ethylene Glycol (EG 100) were determined after 120 minutes of sonication time. The graphene nanofluids with the platelet
S, PalanisamySelvan, Arul Mozhi
A novel sintering method of bridging the two mechanically polished and oriented single-crystals together face-to-face in a non- environmental controlled atmosphere to fabricate the bicrystal substrate of NaCl of macroscopic thickness, with a common zone axis and having planarity over large areas, has been developed. Epitaxial [001] bicrystalline thin face-centered cubic (fcc) metal film of surface-reactive metal-containing tilt grain boundary across the interface is first grown in high vacuum directly by flash deposition on initially fabricated [001] oriented bicrystalline substrate of NaCl. The [001] tilt boundary, thus produced, and is examined by electron microscopy to characterize grain boundary morphology and structure. The findings of some preliminary investigations are then presented. A distinct atomic structure is observed for 310 and 210 inclination. Both HAADF-STEM and Diffraction images reveal that such fabricated high-angle grain boundary accommodates minor deviations from
Dish, NilabhGautam, AbhayBehera, RakeshBanka, HemasunderChavan, Pradeep
The objective of this study is to optimize and characterize an Al6061/Al2O3/MWCNT nanocomposite produced through stir casting. The investigation focused on various concentrations of 2%, 3%, and 5% by weight of Al2O3/MWCNT nanoparticles, with an average Al2O3 particle size of 40 nm. The Al6061 matrix exhibited a uniform distribution of these nanoparticles. Microstructural analysis of the nanocomposite was conducted using scanning electron microscopy. The study examined the tribological properties, including wear and coefficient of friction, as well as the tensile strength and hardness of the Al6061/Al2O3/MWCNT nanocomposites. The results indicated a significant enhancement in mechanical properties, with the ultimate tensile strength (UTS) increasing from 122 MPa to 157 MPa, and the yield tensile strength (YTS) rising from 52 MPa to 76 MPa. At a 5% concentration of Al2O3/MWCNT, the hardness test showed an increase from 28 BHN to 55 BHN. The improvement ratios for 2%, 3%, and 5
Haridass, R.Subramani, N.Viknesh, S.Mathan Kumar, M.Mownitharan, M. S.
The solar-based hybrid automotive vehicle represents a trend marked by technological excellence, offering an efficient, cost-effective, and eco-friendly solution. Besides, the enhancement of solar absorption due to poor weather is influenced by poor solar power with reduced photocurrent density. This research focuses on enhancing the solar power and photocurrent density of conventional solar cells featuring aluminium-doped zinc oxide thin films (AZO) using the Mist Chemical Vapor Deposition (MIST CVD) process with a zinc acetate precursor solution processed at temperatures ranging from 200 to 400°C. To investigate the effect of AZO on the functional behaviour of solar cells, microstructural studies utilizing scanning electron microscopy and X-ray diffraction reveal the concentration of AZO and the alignment of Al/ZnO peaks as even. As a result, this research demonstrates a 21% increase in solar power output compared to conventional Cadmium Telluride (CdTe) cells, with an improvement in
Venkatesh, R.De Poures, Melvin VictorThangamani, P.Manivannan, S.Devanathan, C.Boopathi, M. SugadevaBaranitharan, BalakrishnanMadhu, S.Kaliyaperumal, Gopal
Fused deposition modeling (FDM) is a rapidly growing additive manufacturing method employed for printing fiber-reinforced polymer composites. Nonetheless, the performance of printed parts is often constrained by inherent defects. This study investigates how the varying annealing parameter affects the tribological properties of FDM-produced polypropylene carbon fiber composites. The composite pin specimens were created in a standard size of 35 mm height and 12 mm diameter, based on the specifications of the tribometer pin holder. The impact of high-temperature annealing process parameters are explored, specifically annealing temperature and duration, while maintaining a fixed cooling rate. Two set of printed samples were taken for post-annealing at temperature of 85°C for 60 and 90 min, respectively. The tribological properties were evaluated using a dry pin-on-disc setup and examined both pre- (as-built) and post-annealing at temperature of 85°C for 60 and 90 min printed samples
Nallasivam, J.D.Sundararaj, S.Kandavalli, Sumanth RatnaPradab, R.
A classical way to image nanoscale structures in cells is with high-powered, expensive super-resolution microscopes. As an alternative, MIT researchers have developed a way to expand tissue before imaging it — a technique that allows them to achieve nanoscale resolution with a conventional light microscope.
The development of advanced high-strength steels has become essential in the production of lightweight, safe, and more economical vehicles within the context of the automotive industry. Among the advanced high-strength steels, complex phase steels stand out, characterized by their high formability and high energy absorption and deformation capacity. Laser welding is a technique that applies laser using high energy density as a heat source. It has the advantages that the high welding speed and low heat input compared to other welding methods cause a decrease in deformation, and the narrow width of the weld bead and heat-affected zone allows for the welding of complex parts that would be difficult for other welding methods. Based on a study of a complex phase steel, an analysis was made of the microstructures observed by optical microscopy, the grain boundaries and certain phases contained in this microstructure, as well as the microstructures of each area in the laser welding region
Dias, Erica XimenesReis de Faria Neto, AntonioCastro, Thais SantosMartins, Marcelo SampaioSantos Pereira, Marcelo
This research investigates the impact of friction stir welding (FSW) used to join micro-alloyed steel, on the material and its mechanical characteristics. FSW increases the metallurgical and mechanical qualities of joints made from micro-alloyed steel. However, Friction Stir Welding has produced only modest improvements in connecting steels. Automobile chassis, offshore platforms, oil and gas pipelines, mining, shipbuilding and railroad carriages, pressure vessels, bridges, and storage tanks are just some of the many places and find micro-alloyed steels employed. Frictional heat and tool movement over the joint cause micro defects occurred. Tungsten carbide tools are used in this investigation. Welding shares the same process characteristics, such as the tool's rotating speed (900 rpm) and axial force (10 kN). The table's traverse speed options are available, including 50 mm/min, 60 mm/min, and 70 mm/min. Vickers microhardness testing machines and tensile testing machines are used to
Rajan, C. SakthiKumar, N. MathanKumar, K. VetrivelKannan, S.Soundararajan, S.
This study investigated the effect of nano silica on the mechanical behaviour of blends containing high impact polypropylene (hiPP) and nano clay. This study used nano silica from rice husk ash with an average particle size of 26 nm. The hiPP composites were mixed with 3 wt. % nano clay and different weight percentages (1%, 2%, and 3%) of nano silica were also added. The blending process used twin-screw extrusion, and composite samples were subsequently produced by injection moulding. Various parameters including tensile, compressive, and impact strengths were analyzed. In particular, the hiPP composite containing 3 wt. % nano clay and 2 wt. % nano silica had significantly improved mechanical properties, showing a 37.5% increase in tensile strength, a 56.8% increase in flexural strength, and a 51.4% increase in impact strength. It exhibited the highest tensile (53.51 MPa), flexural (67.19 MPa), and impact strength (5.17 KJ/m2) among all tested composites, demonstrating superior
Thangavel, AnandRagupathy, K.Manivannan, S.Murali, M.
Magnesium (Mg) alloys are becoming ever more ubiquitous as the need for lighter and stronger alloys has increased significantly in the past decades. Mg alloy grade AZ91D is embedded in 0.5 of cerium have a high strength-to-weight ratio and lower specific density, which is useful in the case of automobile applications. An inconclusive study by Lagowski has shown that interrupted age hardening of AZ magnesium alloy increases the yield strength by around 10%. An investigation on the developed AZ91D+0.5Ce alloy subjected to various ageing treatments was carried out in this present study. The various aged samples were investigated by optical microscopy and scanning electron microscopy analysis. The yield strength was also evaluated quantitatively as a function of ageing parameters. A significant increase in yield strength and hardness values was observed in the artificially aged samples due to the precipitation of Mg17Al12 phases.
Venkatesh, R.Manivannan, S.Das, A. DanielMohanavel, VinayagamSoudagar, Manzoore Elahi Mohammad
This Experimental study demonstrates the influence of titanium dioxide (TiO2) and boron carbide (B4C) reinforcements on the mechanical behaviour and microstructural characteristics of lightweight hybrid metal matrix composites (HMMCs) tailored for compact automobile applications. The Aluminium metal matrix composites were synthesized using stir casting technique to ensure uniform dispersion of titanium dioxide (TiO2) and boron carbide (B4C) reinforcements within the aluminium matrix. Characterization techniques such as scanning electron microscopy (SEM) and optical Microscopy, were employed to analyze the microstructural evolution and phase distribution. Mechanical properties such as hardness, tensile strength, and wear resistance were systematically evaluated. The results demonstrated significant enhancements in mechanical performance with 38% increase in tensile strength, 22% increase in impact strength which are attributed to the synergistic effects of TiO2 and B4C. These
Jaswin, M. ArockiaGeetha, R.Mathialagan, SaravananSuresh, S.
In light of the growing demand for Electric vehicles (EVs) as a sustainable mode of transportation, it becomes essential to understand the effect of various abuse conditions that batteries undergo. Vibrational abuse is a significant condition experienced by batteries in operation. Vibrations caused by road roughness, acceleration inertia, and other factors can affect key performance indicators such as cycle life, capacity retention, and safety. These cells undergo various chemical and mechanical reactions over time, leading to the degradation of components like the anode, cathode, electrolyte, separator, and current collector, resulting in reduced performance. Therefore, understanding battery degradation is important for managing system performance. This study is focused on a detailed analysis of Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt (NMC) cells subjected to vibrational abuse. Vibration testing was carried as per International Electrotechnical Commission (IEC
Manwatkar, Asmita AshokPandit, Sachin PrabhakarSantosh Jambhale, MedhaMahagaonkar, Nitin
Growing demand for fuel-efficient vehicles and lower CO2 emissions has led to the development of lightweight materials. Aluminum composites are being used to achieve lightweighting to improve performance, efficiency, and sustainability across various industries. The unique properties of aluminum composites make them an attractive choice for researchers and designers looking to optimize their products. Reinforcement materials play a vital role in the development of these composites, acting as barriers to dislocation movement within the aluminum matrix. This effectively strengthens the material and prevents deformation under load, resulting in increased tensile strength and fatigue resistance. Additionally, aluminum composites exhibit improved thermal and electrical conductivity, making them suitable for automotive applications. In this study, metal matrix composites (MMCs) of aluminum 7075 alloys were developed using silicon carbide (SiC) and flyash as reinforcements. Three different
Manwatkar, Asmita AshokSantosh Jambhale, MedhaMahagaonkar, NitinSharma, Dipesh
Lithium iron phosphate is one of the most important materials for batteries in electric cars, stationary energy storage systems, and tools. It has a long service life, is comparatively inexpensive and does not tend to spontaneously combust. Energy density is also making progress. However, experts are still puzzled as to why lithium iron phosphate batteries undercut their theoretical electricity storage capacity by up to 25 percent in practice. To utilize this dormant capacity reserve, it would be crucial to know exactly where and how lithium ions are stored in and released from the battery material during the charging and discharging cycles. Researchers at Graz University of Technology (TU Graz) have now taken a significant step in this direction. Using transmission electron microscopes, they were able to systematically track the lithium ions as they traveled through the battery material, map their arrangement in the crystal lattice of an iron phosphate cathode with unprecedented
In recent years, deposit formation in fuel systems for heavy-duty engines, using drop-in fuels, have become increasingly common. Drop-in fuels are particularly appealing because they are compatible with existing engines, allowing for higher proportions of alternative fuels to be blended with conventional fuels. However, the precipitation of insoluble substances from drop-in fuels can result in fuel filter clogging and the formation of internal injector deposits, leading to higher fuel consumption and issues with engine drivability. The precise reasons behind the formation of these deposits in the fuel system remain unclear, with factors such as operating conditions, fuel quality, and fuel contamination all suggested as potential contributors. In order to reproduce and study the formation of internal injector deposits, for heavy-duty engines under controlled conditions and to facilitate a more precise comparison to field trials, a novel injector test rig has been developed. This newly
Pach, MayteHittig, HenrikTheveny, ArnaudKusar, HenrikHruby, Sarah
Anode-free sodium metal batteries (AFSMBs) with initial zero sodium anodes are promising energy-storage devices to achieve high energy density and low cost. The morphology and reversibility of sodium controls the cycling lifespan of the AFSMBs, which is directly affected by the separator. Here, we compared the sodium deposition and corresponding electrochemical behaviors under the influence of three commercial separators, which were Celgard 2500, Al2O3-coated PP separator and glass fiber (denoting as 2500, C-PP and GF). Firstly, the reversibility of sodium plating/stripping was tested using half-cells, where coulombic efficiencies were stable at ~99.89% for C-PP and GF compare to 99.65% for 2500, indicating more dead sodium were formed for 2500. Then, the morphologies of deposited sodium were compared using optical microscopy. Compared to inhomogeneous sodium growth under 2500, C-PP obtained more flatter sodium layer with less height difference, attributing to the high mechanical
Qin, NanJin, LimingZheng, Jim P.
To combat corrosion and wear issues of automotive brake discs, many manufacturers have introduced various surface treatment technologies, such as thermal spraying, laser cladding, and ferritic nitrocarburizing (FNC). Besides those surface treatment technologies, a plasma electrolytic aluminating (PEA) process has also shown to be effective in producing alumina-based ceramic coatings on cast iron substrates, providing an enhanced corrosion resistance. In this study, the PEA-coated brake rotor and FNC-treated brake rotor were comparatively tested in various corrosion conditions, including an electrochemical corrosion test and simulative corrosion experiment, before and after a road driving test. A scanning electron microscope (SEM) and an energy-dispersive X-ray (EDX) were used to observe and analyze morphology and chemical compositions of the surfaces and cross-sections of the tested rotors. The results showed that the new PEA-coated brake rotor demonstrated the best corrosion
Liu, YintingNie, Xueyuan
Researchers at the National Institute of Standards and Technology (NIST) and colleagues have developed standards and calibrations for optical microscopes that allow quantum dots to be aligned with the center of a photonic component to within an error of 10 to 20 nanometers (about one-thousandth the thickness of a sheet of paper). Such alignment is critical for chip-scale devices that employ the radiation emitted by quantum dots to store and transmit quantum information.
This research explores the tribological characteristics of brake friction materials, focusing on synthetic iron-based sulfides with unique microstructures. Tribological testing, conducted per the SAE J2522 and SAE J2707 standards across diverse temperatures, reveals the superior performance of brake pads incorporating composite iron sulfide, especially at high temperatures. These pads exhibit stable friction levels and reduced wear compared to those utilizing pure iron sulfide, signifying a noteworthy advancement in overall tribological properties. A comprehensive cross-sectional analysis of friction materials using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS) reveals chemical alterations. Pure iron sulfide undergoes extensive oxidation compared to composite iron sulfide, which exhibits oxidation near the friction surface due to differences in the oxidation mechanism because of the differential microstructure. Furthermore, Thermogravimetric Analysis
Jara, Diego ChavezLorenzana, CarlosCotilli, EdoardoSliepcevich, AndreaConforti, Michael
The viscoelastic response of pure Al and commercial 6082 and 6082-T6 (Al–Mg–Si) alloys is measured with dynamic–mechanical analyzer as a function of temperature (ranging from 35 to 425°C) and loading frequency (ranging from 0.01 to 100 Hz). The measured data (the storage modulus, loss modulus, and mechanical damping) are compared to available transmission electron microscopy and differential scanning calorimetry data, to ascertain whether unexplained variations of the viscoelastic behavior of the alloys can be correlated to phase transformations. The results suggest that some of these variations may be controlled by the formation and dissolution of metastable phases, such as Guinier–Preston (GP) zones and phases β″, β′, and B′. Indeed, GP zones and phase β″ have been reported to control other mechanical properties. However, due to the high complexity of the aging path of Al–Mg–Si alloys, with formation and dissolution reactions of many precipitate types overlapping along wide
Rojas, Jose I.Contel, AlejandroCrespo, Daniel
The present study discusses the effect of installation torque on the surface and subsurface deformations for thin-walled 7075 aluminum alloy adapters used in Aerospace applications. An FE model was constructed to predict the effect of torque-induced stresses on thin-walled geometry validated with experimentation. A detailed surface analysis was performed on 7075 aluminum to check superficial discontinuities, residual stresses, and grain deformations. The localized strain hardening resulting from increased dislocation density and its effect on surface microhardness was further studied using SEM (Scanning Electron Microscope). The predicted surface level plastic strain of .25%, on the castle nut adapter, was further validated with grain deformations measured using optical and scanning electron microscopy.
Yarolkar, MakrandHarish, UppuPatil, SandipPatil, Manasi
Hydraulic systems in aircraft largely comprise of metallic components with high strength to weight ratios. Some examples of such material include Aluminum and Titanium alloys which are typically chosen for low and high-pressure applications respectively. For aircraft fluid conveyance products, hydraulic conduits are fabricated by axisymmetric turning to support flow conditions. The hydraulic conduits can have grooved interfaced design within for placement of elastomeric sealing components. This article presents a systematic study carried out on common loads experienced by fluid carrying conduits and the failure modes induced. Firstly, a static structural analysis was carried out on each of the geometries of the test articles to identify the locations having areas of high stress concentration. Test articles of various wall thicknesses and internal diameters were pressure impulse tested at different conditions of side loads to identify cycle numbers till failure and failure locations. On
Paidimarri, VishalJacob, KrupaHarish, UppuHovis, David
This study focused on the synthesis and characterization of monodisperse spherical TiO2 nanoparticles doped on the surface with Se (IV) in order to increase the mechanical properties of the bonded joint reinforcing. Work will begin with the synthesis of monodisperse quasi-spherical TiO2 nanoparticles with a modal diameter of less than 20 nm, using the sol-gel technique. Se (IV) selenium surface doping changed the specimen’s chemistry and physics. Different initial concentrations of the doping element will be tested. Next, a physicochemical characterization of the different solid systems will be carried out in order to determine the effect of the doping element on the properties of titanium dioxide. Their morphology and size will be studied through transmission electron microscope observations; volume chemical composition by X-ray diffraction analysis, EDX (energy-dispersive X-ray), and XRF (X-ray fluorescence). The careful selection of 4% and 6% concentrations produced the optimum
Hadjez, FayssalMaouche, HichemBoumediri, HaithemChorfi, SofianeBoukelia, Taqiy Eddine
As one of the pollutants that cannot be ignored, soot has a great impact on human health, environment, and energy conversion. In this investigation, the effect of residence time (25ms, 35ms, and 45ms) and ammonia on morphology and nanostructure of soot in laminar ethylene flames has been studied under atmospheric conditions and different flame heights (15 mm and 30 mm). The transmission electron microscopy (TEM) and high-resolution transmission electron microscope (HRTEM) are used to obtain morphology of aggregates and nanostructure of primary particles, respectively. In addition, to analyze the nanostructure of the particles, an analysis program is built based on MATLAB software, which is able to obtain the fringe separation distance, fringe length, and fringe tortuosity parameters of primary particles, and has been verified by the multilayer graphene interlayer distance. It is found that soot is mainly composed of tens of primary particles in the form of tree-like at HAB (height
Qian, WeiweiShi, XiuyongLi, Song
Crankshaft bearings function to maintain the lubrication oil films needed to support crankshaft journals in hydrodynamic regime of rotation. Discontinuous oil films will cause the journal-bearing couple to be in a mixed or boundary lubrication condition, or even a bearing seizure or a spun bearing. This condition may further force the crankshaft to break and an engine shutdown. Spun bearings have been identified to be one of the top reasons in field returned engines. Excessive investigations have found large, embedded hard debris particles on the bearings are inevitably the culprit of destroying continuity of the oil films. Those particles, in particular the suspicious steel residues, in the sizes of hundreds of micrometers, are large enough to cause oil film to break, but rather fine and challenging for materials engineers to characterize their metallurgical features. This article presents the methodology and steps of debris analyses on bearings at different stages of engine build
Yang, JianghuaiWang, QiguiLi, Zhe
Unlike conventional heat shrink tubes or enclosure systems which only seals wires and splices on the outside, a novel Acrylate based sealing technology developed and introduced by Eurotech is a low viscosity fluid formulated to be applied to the splices either in liquid droplets or by dipping, utilizes fast capillary-wicking action and quick self-cure inside the wires to form a robust, cost effective, flexible, impenetrable seal to prevent moisture damage of wire harnesses and associated electrical components. This technology is an enabler of new wire harness architectures currently limited by the shortcomings of conventional sealing products such as heat shrink tubes which come up short when the splice configurations or geometries become too complex or difficult for sealing from the outside. Sealing mechanism investigation was launched and the results of the analytical experiments are presented to reveal how this unique sealing technology works to effectively withstand pneumatic air
Chung, Dennis
Super duplex stainless steel (SDSS) is a type of stainless steel made of chromium (Cr), nickel (Ni), and iron (Fe). In the present work, a 1.6 mm wide thin sheet of SDSS is joined using gas tungsten arc welding (GTAW). The ideal parameter for a bead-on-plate trial is found, and 0.216 kJ/mm of heat input is used for welding. As an outcome of the welding heating cycle and subsequent cooling, a microstructural study revealed coarse microstructure in the heat-affected zone and weld zone. The corrosion rate for welded joints is 9.3% higher than the base metal rate. Following the corrosion test, scanning electron microscope (SEM) analysis revealed that the welded joint’s oxide development generated a larger corrosive attack on the weld surface than the base metal surface. The percentages of chromium (12.5%) and molybdenum (24%) in the welded joints are less than those in the base metal of SDSS, as per energy dispersive X-ray (EDX) analysis. Corrosion modeling is done using the COMSOL
Kumar, SujeetKumar, YogeshE. K., Vimal K.
Natural fiber-reinforced composites are increasingly used in the automotive and aerospace industries since more studies focus on them because they are environmentally benign. The primary benefit of natural fibers over synthetic fibers is their biodegradability. In addition to meeting other standards, natural fiber-reinforced composites have high thermal and mechanical qualities. The current study’s main objective has been to investigate one such natural fiber-reinforced polymer. Biomaterials constructed of Abutilon indicum fiber reinforced with polyester were created in the current work. The test samples with the materials above underwent mechanical and thermal investigations to determine their strengths. The impact of alkali treatment (NaOH) on the fibers was also investigated and assessed. Compared to other samples such as 5, 10, and 15 g of fiber loadings the 20 g of fiber loading reveals the highest mechanical properties such as 59.21 MPa tensile, 72.45 MPa of bending, and 11.25 kJ
Kaliappan, SeeniappanNatrayan, L.Mohammed Ali, H.Kumar, Pankaj
In the aerospace industry, large aircrafts employ composite materials for making complex structures which not only reduces weight and cost but also reduces the number of joints. Irrespective of that joining of structures cannot be avoided and for that mechanical fasteners such as rivets and bolts are employed along with adhesive bonding. Further, in recent years natural fibers have been studied extensively for their numerous advantages and have already been made into several automotive applications. Keeping these current trends in mind an attempt is made to investigate the joining behavior of natural fiber composites experimentally. So in this study, the ultimate failure load, bearing strength and the dominating failure mode of jute-hemp fabric-reinforced polymeric composites joined using single and double-bolted configurations are studied. The polymeric composite laminates were successfully fabricated using resin infusion technique and test specimens were fabricated following ASTM
Koppad, PraveennathChinnakurli Suryanarayana, RameshReddy, NagarajaSethuram, D
Additive manufacturing (AM) is a common way to make things faster in manufacturing era today. A mix of polypropylene (PP) and carbon fiber (CF) blended filament is strong and bonded well. Fused deposition modeling (FDM) is a common way to make things. For this research, made the test samples using a mix of PP and CF filament through FDM printer by varying infill speed of 40 meters per sec 50 meters per sec and 60 meters per sec in sequence. The tested these samples on a tribometer testing machine that slides them against a surface with different forces (from 5 to 20 N) and speeds (from 1 to 4 meters per sec). The findings of the study revealed a consistent linear increase in both wear rate and coefficient of friction across every sample analyzed. Nevertheless, noteworthy variations emerged when evaluating the samples subjected to the 40m/s infill speed test. Specifically, these particular samples exhibited notably lower wear rates and coefficients of friction compared to the remaining
Surendra, S.Sireesha, S.C.P., SivaSuresh, P.
Effect of Lanthanum addition on mechanical properties of LA93 along with its microstructural evolution has been analysed using optical microscopy, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The phases of this alloy were identified by X-ray diffraction (XRD). La addition has resulted in a reformed semi continuous structure with a decrease in grain volume along the boundary. The morphology shows the formation of Al2La and Al3La phase while the AlLi in LA93 has decreased. At 1.5 wt% La addition, the maximum grain refinement is obtained. In LA93+xLa, the Al2La and Al3La appear as a white long stripy phase and a white large blocky phase, respectively, and contribute to the increased strength of the alloy. There is a clear distribution of intermetallic compounds along the grain boundary of α-Mg and inside the matrix. The ultimate tensile strength increases by 60% to 112 MPa and hardness increases by 48% when the La content is 1.5 wt%. This improvement can be
Manivannan, S.Vallimanalan, A.Daniel Das, A.Marimuthu, S.Suresh Balaji, R.
The current research examines the structural and mechanical properties of sheets made from the 8561 aluminum alloy using the dynamic stir procedure. After being treated perpendicular to the direction of rolling, the compressive material characteristics of the strips were investigated at room temperature in the longitudinal and vertical dimensions relative to the treatment orientation. Tensile tests at the grain boundary were also performed at relatively high temperatures and different strain rates to assess the ductile mechanical properties of the crystallization substance and to ensure the distinctions from the parent material caused by the dynamic stir process. Tensile testing at temperatures and strain rates ranging from 380 °C to 780 °C was employed in parallel studies of the material's behavior at high temperatures. Electron microscopy was used to examine the fracture surfaces of specimens evaluated at various temperatures.
Srinivasan, V.P.Duraithilagar, S.Santhosh, S.Bharani Kumar, S.Karthi, V.
This study focuses on the development of a hybrid composite, incorporating natural fibers—specifically, banana and flax fibers—within a polyester resin matrix. Different volume ratios of banana and flax fibers were systematically employed to create the composite, with a particular emphasis on achieving optimal fabrication processes through compression molding. The mechanical properties of the resulting hybrid composite were comprehensively assessed through tensile, impact, and flexural testing using a Universal Testing Machine (UTM). Morphological analysis, facilitated by a Scanning Electron Microscope (SEM), provided insights into the internal structure of the composite. Additionally, numerical analysis utilizing ANSYS software was employed to further understand the composite's behavior. The findings unveiled that the hybrid composite demonstrated superior strength compared to single-fiber composites. This research contributes to advancing our understanding of hybrid composites
Velmurugan, SanthoshJanakiraman, ThiagarajanNandhini, S.Ganesha Rathinam, M.
Utilizing a scanning electron microscope, research was conducted on the formation of fatigue microcracks in a cast AF620 alloy. The results of fatigue microcrack propagation under escalating levels of stress indicate that the interdendritic or grain boundaries of Al grains are crucial for microcrack propagation. In Al78Zn25 regions, fatigue fractures frequently form within the grains, but if the stress concentration is high enough, they can also form at the base of the crevice on the grain boundaries. The fatigue fracture propagates in a wave-like pattern under a microscope. It was proposed that the length of the crack and the rate of formation of fatigue microcracks could be correlated to ascertain the opening displacement at the tip of the crack.
Sandeep, ChSelvarajan, L.Balu Mahandiran, S.Murugan, K.Sasikumar, R.Srinivasan, V.P.
As anyone who has ever skimmed a book or magazine can tell you, sometimes you don’t have to read every word to grasp the essence. Inspired by this notion, scientists are harnessing the power of artificial intelligence (AI) to enable a form of “speed reading” in microscopy. This could revolutionize the way researchers acquire data and allow them to preserve the integrity of precious samples.
This work aims to develop potential super hydrophilic cross-linked smart polymer composites and condensation management device (CMD) for condensation control in automotive headlamps. Condensation and moisture buildup in the automotive headlamp decrease the visibility to the driver. The super hydrophilic cross-linked polymer composites were prepared with the combination of polyacrylamide-based hydrogels and hygroscopic lithium bromide desiccants. In this work, we have utilized various desiccants such as calcium chloride (Desiccant-1), silica gel (Desiccant-2) and lithium bromide (Desiccant-3) which is blended together with the polyacrylamide-based hydrogel. The prepared various compositional smart materials have been analyzed for structural, morphological, thermal and functional properties using fourier transform infrared spectroscopy (FTIR), optical microscopy (POM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC) and water
Chandkoti, IkhlasNaikwadi, AmolMali, Manoj
Obtaining high-resolution images in the world of microscopy has long been a challenge. Deconvolution, a method to enhance image clarity, often amplifies noise between the sample and the image. Researchers at Boston University recently developed a novel deblurring algorithm that avoids these issues, improving the resolution of images with photon intensity conservation and local linearity.
Single point incremental forming (SPIF) is a robust and new technique. In the recent research scenario, materials properties such as microstructure, micro-texture analysis, and crystal structure can be accessed through characterization non-destructive techniques, e.g., scanning electron microscope (SEM), electron backscattered diffraction (EBSD), and X-ray diffraction (XRD). XRD is a non-destructive method for analyzing the fine structure of materials. This study explores how process variables such as wall angle, step size, feed rate, and forming speed affect the parts of large-, medium-, and small-sized truncated cones of aluminum alloy AA3003-O sheet. Several cone parts of truncated cones are used in this investigation to implement Scherrer’s method. The two primary determining factors peak height and crystallite size are assessed for additional analysis in the present research. Observing and evaluating different types of large-, medium-, and small-sized truncated cones are to
Bhasker, Radhe ShyamKumar, YogeshForouhandeh, Fariborz
Processes and structures within the body that are normally hidden from the eye can be made visible through medical imaging. Scientists use imaging to investigate the complex functions of cells and organs and search for ways to better detect and treat diseases. In everyday medical practice, images from the body help physicians diagnose diseases and monitor whether therapies are working. To be able to depict specific processes in the body, researchers are developing new techniques for labelling cells or molecules so that they emit signals that can be detected outside the body and converted into meaningful images. A research team at the University of Münster has now adapted a cell labelling strategy currently used in microscopy — the so-called SNAP-tag technology — for use in whole-body imaging with positron emission tomography (PET).
The main objective of the work is to investigate the friction and wear behavior of sintered copper-based brake composite friction material with a change in the volume percentage of soft reinforcement particles namely MoS2 by pin-on-disc tribometer for medium-duty automotive applications. The composite brake friction material contains copper (Cu) as a matrix, tin (Sn) as an additive, silicon carbide (SiC) and molybdenum disulfide (MoS2) as hard and soft reinforcement particles and barium sulfate (BaSO4) as filler. These hybrids copper-based brake composite friction (pin) samples are successfully prepared by a change in compositions of MoS2 from 0 to 5 vol. % in the step of 1 vol. % and the characterizations of friction samples are studied to understand the physical and mechanical properties such as density, hardness, and compressive strength. Finally, the dry sliding friction and wear test is conducted against grey cast iron material (disc) at constant load and sliding speed of 50 N and
P, RajaRamkumar, Penchaliah
The uses of fillers in composites are creating new opportunities in the composite industry. Hollow Glass Microspheres (HGM) are Soda-lime-borosilicate glass hollow spheres with thin walls used as low-density filler material which can reduce final part weight by up to 15% or more without compromising the mechanical integrity. Glass bubbles take up 20 times the space of normal mineral filler, lowering the cost per unit volume; hence, the need for weightless and high-strength materials for state-of-the-art engineering applications may be met by HGM reinforced composites. Epoxy being a key structural material for marine, automotive and aerospace applications, is known for its brittle nature, poor mechanical and thermal properties and to date, not much work has been done on hollow glass microspheres reinforced carbon epoxy composites, however few systematic studies showing the influence of reinforcements on mechanical and thermal properties of carbon epoxy/HGM composites were conducted
K, TejasviRanga, K. V SS, GurusideswarSingh, P. Sundar
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