Showing papers in "Advanced Materials Research in 2018"
TL;DR: In this article, the results of X-ray florescent: XRF, silica content which was obtained after heat treatment at 700 °C for 6 h was 80.814 wt%.
Abstract: Sugarcane bagasse is an agricultural waste that is potentially used as natural silica resources. Natural silica claimed to be safe in handing, cheap and can be generate from cheap resource. In the objectives of this study were to prepared silica from Sugarcane bagasse. The preparation of Sugarcane bagasse ash by burning at 700 °C for 4 and 6 h, respectively in atmosphere. The result of X-ray florescent: XRF, silica content which was obtained after heat treatment at 700 °C for 6 h was 80.814 wt%. Bagasse ash was purified by alkaline extraction method with 1.5, 2 and 2.5 N sodium hydroxide (NaOH), respectively. And refluxed by using concentrated 2 N sulfuric acid. From X-ray diffraction pattern showed that the obtained products were amorphous silica, 2.5 N sodium hydroxide. The morphology was observed by SEM, sphere and average particles dimension of synthesis silica with 1.5, 2 and 2.5 N NaOH are 120, 100 and 80 nm respectively. The SEM micrographs showed that the Concentration of NaOH was increased, the particles dimension decreased
11 citations
TL;DR: In this article, a combination of nanocrystalline α-Al2O3 and Υ-Al 2O3 was identified in the MAO coating using X-ray diffraction analysis.
Abstract: Micro Arc Oxidation (MAO) coating was performed on Al-2014 aluminium alloy in aqueous solution of silicate, phosphate and hybrid electrolytic environments. The MAO thickness was measured around 5-15 μm, in which significant thickness of both dense and porous layers were identified. A combination of nanocrystalline α-Al2O3and Υ-Al2O3 was identified in the MAO coating using X-ray diffraction analysis. The thickness and morphology of the coating, which is analyzed using SEM are different for different MAO process parameters and it was found that the MAO coating prepared in phosphate electrolyte is giving a better coating with higher coating thickness, minor pore size and better adherence.
9 citations
TL;DR: In this paper, the effect of ground granulated blast furnace slag (GGBFS) on compressive strength and durability of concrete was investigated and it was shown that GGBFS concrete with 40% cement replacement (G40) has the highest compressive power.
Abstract: Facing the cement and concrete development process, reducing greenhouse gases and the consumption of natural resources has become an important issue. To reduce the cement content in concrete, the increased use of concrete combining large amounts of industrial by-products is expected. Ground granulated blast furnace slag (GGBFS) has been used as a supplementary cementitious material in ordinary Portland cement (OPC) concrete. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40%, and 60% by weight were used to produce concrete. Compressive strength test, water absorption, electrical resistivity, and rapid chloride penetration test (RCPT) were performed to investigate the effect of GGBFS on compressive strength and durability of concrete. Test results show that GGBFS concrete with 40% cement replacement (G40) has the highest compressive strength. The water absorption and chloride permeability reduced with the increasing cement replacement percentage by GGBFS. Meanwhile, the electrical resistivity increased with an increasing GGBFS replacement percentage. Based on the results, GGBFS concrete with 40% cement replacement seems to be the optimum replacement in this study.
8 citations
TL;DR: In this article, some existing biomimetic design strategies applied for nature emulation are presented with the aim to understand the contribution of biomimetics to the design culture, and case studies show the diversity of possible applications of natural phenomena in architecture with the goal to provide user-friendly tools that can facilitate the generation of more indepth insights, opening new perspectives for new possible technical solutions and showing the potential of nature adaptations to environmental conditions at different climate.
Abstract: Smart surfaces and materials can play a significant role in intelligent, adaptive and responsive envelopes because of these intrinsic properties. The environmental question and energy efficiency in which the construction sector is involved, is in a process that can not be interrupted and that puts researchers and designers in front of a scientific and design challenge in which it is necessary to contribute to find different ways of study and experimentation on new materials and constructive languages, ranging from the application, to the structural, design and molecular, to mention the main ones. The development of technologies is helping architects of the “biomimetic current” to recreate complex structures that can be found in nature, using innovative construction methods and materials. In this paper, some existing biomimetic design strategies applied for nature emulation are presented with the aim to understand the contribution of biomimetic materials to the design culture. Case studies show the diversity of possible applications of natural phenomena in architecture with the aim to provide user-friendly tools that can facilitate the generation of more indepth insights, opening new perspectives for new possible technical solutions and showing the potential of nature adaptations to environmental conditions at different climate.
7 citations
TL;DR: In this paper, an original experimental campaign was conducted on non-Hazardous Waste Incineration aggregates, which was conducted in two phases: Scanning Electron Microscopy (SEM) and instrumented indentation.
Abstract: An original experimental campaign never conducted until now on Non-Hazardous Waste Incineration aggregates is presented in this paper. The experiments were conducted in two phases: Scanning Electron Microscopy (SEM) and instrumented indentation. A cartography followed by a series of Quantitative Chemical Microanalysis (QCM) was carried out on the 0/12.5 mm fraction of the particle size distribution. Instrumented indentation tests were carried out on isolated particles of 25 mm in diameter. Observations at the SEM yielded the exact chemical composition of the bottom ashes. It has been found that the proportions of the chemical elements composing the material are slightly different from those of other studies. This difference has made it possible to note that the zone of production of the bottom ash significantly influences their physicochemical characteristics. From the indentation curves obtained, the “Olivier and Pharr” method was used to determine the reduced modulus of elasticity “Er”. Mean values of approximately 65 GPa and 40 GPa were obtained respectively for vitreous phases and less vitreous ones.
7 citations
TL;DR: In this article, the composition of polysilicate solutions obtained by mixing liquid glass and silica sol has been investigated and a correlation between the content of high-polymer fractions of silicic anions in a poly-silicate solution and the tensile strength of films has been found.
Abstract: Information is provided on the composition of polysilicate solutions obtained by mixing liquid glass and silica sol. It was found that the introduction of the sol leads to an increase in the silicate module and contributes to an increase in the fraction of high-polymer fractions of the silicon-oxygen anions. The results of the kinetics of the variation of α-SiO2 and β-SiO2. It is shown, that coatings based on the polysilicate solutions are characterized by faster curing. The was found correlation between the content of high-polymer fractions of silicic anions in a polysilicate solution and the tensile strength of films. Increase in the g-SiO2 content promote increase in the tensile strength of films. The composition of sol silicate paint is developed. Coatings based on paint have a high performance property.
6 citations
TL;DR: In this paper, the use of auxetic metamaterials, specifically engineered to obtain properties beyond those found in nature, to generate structures with adaptive curvature obtained from planar construction elements is discussed.
Abstract: Advancements in computational tools are offering designers the possibility to change their relationship with materials and establishing new synergies between matter, form and behaviour. This work explores this paradigm by introducing the use of auxetic metamaterials, specifically engineered to obtain properties beyond those found in nature, to generate structures with adaptive curvature obtained from planar construction elements. It is discussed how through programming an initial geometry with the strategic negotiation of several geometrical parameters it is possible to control finely the structural and morphological features of a structure. The paper presents approach, tools and methods for designing auxetics for large scale applications, and use them to create heterogeneous active-bending structures.
6 citations
TL;DR: In this paper, the potentials of different wood constructions for the renovation and extension of existing buildings for sustainable urban renewal are discussed, and the results confirm the significant advantages of timber constructions regarding all aspects.
Abstract: This paper discusses the potentials of different wood constructions for the renovation and extension of existing buildings for sustainable urban renewal. The renovation and extension of existing buildings with wood constructions can contribute significantly to sustainable urban redevelopment. The renovation of building envelopes, such as façades and roofs, with highly insulated wooden components, can reduce the transmission heat losses and related heating energy demand of existing buildings significantly. The extension of existing buildings contributes to the redensification of urban areas and can create synergies with the improvement of existing buildings’ performances. The manifold advantages of specific wooden constructions can be related to different aspects, such as construction type and material properties, building execution, design, logistic and sustainability. The results of this research discuss the architectural design and planning relevant properties of specific timber construction types, such as wood frame, cross-laminated timber (CLT), massive timber, and hybrid timber-concrete, considering the properties of different soft (such as spruce) and hard (such as beech) construction timber species. Timber constructions are compared with conventional massive constructions out of concrete and steel. The results confirm the significant advantages of timber constructions regarding all aspects.
6 citations
TL;DR: In this article, the results of the welding experiments were presented, especially with the difficulties of the filler material selection; along with the result of the fatigue crack growth examinations executed on the base materials and its welded joints.
Abstract: The objective of the paper is to present the newest results of our complex research work. In order to determination and comparison of the fatigue resistance, fatigue crack growth tests were performed on different grades of S690QL quenched and tempered, and S960TM thermomechanically rolled high strength steels. 15 mm and 30 mm thick base materials were used for our investigations. Welded joints were made from these base materials, using gas metal arc welding with matching, overmatching, and undermatching filler metals. In the paper, the performance of the welding experiments will be presented, especially with the difficulties of the filler material selection; along with the results of the fatigue crack growth examinations executed on the base materials and its welded joints. Statistical aspects were applied both for the presenting of the possible locations of the cracks in the base materials and the welded joints and for the processing of the measured data. Furthermore, the results will be compared with each other, and the possibility of derivation of fatigue crack propagation limit curves will be referred.
6 citations
TL;DR: In this article, the microstructure of low-alloy wear-resistant steels is correlated with corrosion properties of low alloy wear resistant steel and the presence of martensite and fine carbide precipitates in the matrix has been found to improve wear and corrosion resistance.
Abstract: Wear-resistant low alloy steels containing elements like Cr, Mo, attain their properties due to precipitation of carbides upon heat treatment. These steels are widely used for components in earthmoving and mining equipment. Even though the mechanical properties and wear behaviour of these steels are studied extensively, the studies on nature of carbide precipitation and their influence on corrosion behaviour are very rare. The present work attempts to correlate the microstructure with corrosion properties of low alloy wear resistant steel. After quenching from hot working temperature of about 900 °C, the alloy is subjected to tempering at two different temperatures i.e. 150 °C & 300 °C for durations of 1 h and 4 h. Two competitive process occur simultaneously effecting the hardness of the alloy during tempering i.e. (i) Softening due to transformation of martensite with depleting carbon (ii) Increase in hardness due to formation of carbide precipitates in the matrix. Transmission electron microscopy (TEM) of as quenched condition revealed fully martensite structure in the alloy. TEM investigation of 150 °C/ 4 h tempering condition, revealed presence of some amount of martensite and fine carbide precipitates in the alloy. TEM micrographs of 300 °C/ 4 h condition revealed relatively coarse carbides in a softer ferrite matrix. The presence of martensite and fine precipitates, resulted in relative improvements in wear and corrosion resistance respectively, for the alloy tempered at 150 °C for 4 h, when compared to the alloy tempered at 300 °C for 4 h.
6 citations
TL;DR: In this article, a filter paper cellulose with average degree of polymerization (DP) of 1000-1300 was dissolved in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) firstly, and then acidic ionic liquids (ILs), ([(CH2)3SO3HVIm]HSO4) as the catalyst was applied to hydrolyze the FP cellulose by microwave heating.
Abstract: The hydrolysis of cellulose into platform compounds and chemicals fuels has gained much attention to relieve the global energy crisis and environmental pollution. The filter paper (FP) cellulose with average degree of polymerization (DP) of 1000-1300 was dissolved in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) firstly. And then acidic ionic liquids (ILs), ([(CH2)3SO3HVIm]HSO4) as the catalyst was applied to hydrolyze the FP cellulose by microwave heating. Compared with the oil bath heating method, microwave heating could effectively increase the total reducing sugars (TRS) yield about 10.7%. When the ratio of ILs catalyst to FP (w/w) was 0.167, and the ratio of deionized water to FP (w/w) was 0.833, the TRS yield was up to 60.8% within 20 min at 100°C.
TL;DR: In this paper, the effects of different mixing amount of carbon fiber and the sand ratio in concrete and the curing time of concrete and relationships between these factors were investigated, and the compressive strength of concrete with different mixing amounts of carbon fibres peaks when the sand ratios was 31% and when the carbon fiber mixing amount was 0.8%.
Abstract: With the rapid development of construction, the high quality of the construction material is required. Mixing carbon fiber in concrete attracts more and more attention as it can reinforce concrete. However, the science research and engineering application of carbon fiber reinforced concrete is relatively few. In this paper, the effects of different mixing amount of carbon fiber and the sand ratio in concrete and the curing time of concrete and relationships between these factors were investigated. Proper carbon fiber and sand ratio can promote the compressive strength of concrete and it has a good resistance to cracking. The compressive strength of concrete with different mixing amounts of carbon fiber peaks when the sand ratio was 31% and the compressive strength was better when the carbon fiber mixing amount was 0.2% and 1% than any other ratios after 28 days. When the sand ratio was 31%, the compressive strength of carbon fiber mixing amount increased with the increase of curing time and it reached the top when the carbon fiber ratio was 0.8%. The mixing amount of carbon fiber also had a great influence on the early compressive strength to some extent. We anticipate that the research can offer certain reference for engineering practice.
TL;DR: In this article, the authors evaluate the mechanical properties of Aluminum 2024 T351 reinforced with Blast Furnace Slag and Red Mud and find that the composite with 2% Blast furnace slag and 3% Red Mud outperforms the uni-reinforced matrix composites.
Abstract: In the present days, hybrid metal matrix composites exhibit the better mechanical properties when compared with the uni-reinforced metal matrix composites. Due the light weight and improved mechanical properties these materials find the better applications in the area of aerospace and automobiles. The present investigation aims to evaluate the mechanical properties of Aluminum 2024 T351 reinforced with Blast Furnace Slag and Red Mud. Composites with industrial wastes like blast furnace slag and red mud as reinforcements are likely to overcome the cost barrier for wide spread applications. Blast Furnace Slag particulates are reinforced in AA2024 by decreasing 4 to 1% by weight. Red Mud particulates are reinforced in AA2024 by increasing 1 to 4% by weight. The composites are synthesized by using the stir casting technique. The mechanical properties are optimized for the composite with 2% Blast furnace slag and 3% Red Mud. Micro structural studies carried out using SEM, reveals the uniform distribution of the reinforcement in the matrix phase.
TL;DR: In this article, a new experimental model of specialized equipment has been used for certain experiments to make these functional layers of aluminium alloy on steel, and the presented processes are ecological, because they do not need lubricants or other toxic substances and do not produce chips or harmfull substances.
Abstract: Coating of steel with aluminium alloy is needed for the execution of a functional layer for corrosion protection. Some experiments have been performed on square-section tubes (50 mm x 50 mm) of S235 steel, according to EN 10 025, to be coated with 1 mm thick sheets of EN AW 5754 aluminium alloy that have been previously bended as U shaped profiles. A new experimental model of specialized equipment has been used for certain experiments to make these functional layers of aluminium alloy on steel. Firstly, friction drilling and threading by form tapping, followed by screws-mounting without nuts have been used to make such joints. Several holes have been executed by a Ø4.3 friction drilling tool, then an M5 form tap was used for threading. For friction drilling, tools with 90% tungsten carbide content and 1 micron grain size were applied. By threading, TiN coated form taps have been used. Secondly, overlap friction stir welding (FSW) has been applied, to make a functional layer of aluminium alloy on a 50 mm x 50 mm S235 steel tube. The wings of the U profiles were overlapped. A quenched FSW tool, own-made of C 45 grade steel, EN 10083, has been used for these joining tests. The joining parameters are mentioned for each process. The run of each joining process is described and the joint test samples are presented. The appearance of the screw-mounted functional layers is appropriate. The metallographic analysis has revealed adequate form of the burr formed below the hole. The burr height is 2.5 – 3.2 mm. The pattern of the M5 thread is appropriate. No defects have been detected on the holes and threads. The appearance of the FSW functional layers is adequate. Metallographic analysis shows that FSW joints of the overlapped aluminium alloy sheets are adequate, because there is no gap between these sheets. There is only a narrow gap between the aluminium alloy bottom sheet and the wall of the steel tube, which proves an appropriate positioning of the two metals. No defects were detected, except for a weld flaw, as a small and isolated cavity, with a section less than 0.1 mm2, considered within the acceptance limit, according to EN 25239-5. The U shaped sheets of aluminium alloy are firmly fixed on the square steel tube, for both coating types. The mentioned processes are proposed to increase productivity in industrial technologies for series production. The processes addressed in this paper are more rapid than conventional processes. Adequate preparation of the parts to be welded, mechanization and automation allow repeatability and quality. The target applications are coated structure elements for devices, appliances, tools, welded structures or automobiles. The involved industrial areas of the applications are: manufacturing, electro-technique, construction and automotive industries. The presented processes are ecological, because they do not need lubricants or other toxic substances and do not produce chips or harmfull substances.
TL;DR: In this paper, an attempt has been made to measure vibrations using ADXL335 accelerometer interfaced to computer using Arduino and the measured values are then used to optimize the machining process.
Abstract: During machining any material, vibrations play a major role in deciding the life of the cutting tool as well as machine tool. The magnitude acceleration of vibrations is directly proportional to the cutting forces. In other words, if we are able to measure the acceleration experienced by the tool during machining, we can get a sense of force. There are many commercially available, pre-calibrated accelerometer sensors available off the shelf. In the current work, an attempt has been made to measure vibrations using ADXL335 accelerometer. This accelerometer is interfaced to computer using Arduino. The measured values are then used to optimize the machining process. Experiments are performed on Brass. During machining, it is better to have lower acceleration values. Thus, the first objective of the work is to minimize the vibrations. Surface roughness is another major factor which criterion “lower is the better” applies. In order to optimize the values, a series of experiments are conducted with three factors, namely, tool type (2 levels), Depth of cut (3 levels) and Feed are considered (3 levels). Mixed level optimization is performed using Taguchi analysis with L18 orthogonal array. Detailed discussion of the parameters shall be given in the article.
TL;DR: In this paper, a new technological solution was proposed for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding.
Abstract: Within the WELLFORMED research project, ongoing at the CEMSIG Research Center of the Politehnica University of Timisoara, a new technological solution was proposed for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding. The research project integrates an extensive experimental program on such beams, using full scale specimens, to demonstrate the feasibility of the proposed solutions and to assess their performance, followed by numerical simulations to characterize and optimize the connecting details. The present paper presents the results of a large experimental program, on small specimens subjected to shear, consisting of two or three layers of steel sheet connected by spot welding.
TL;DR: In this paper, the grey relational analysis (GRA) method is applied to determine an optimal set of process parameters for machining Ti49.4-Ni50.6 shape memory alloy (SMA) for orthopedic implant application.
Abstract: The present work deals with the optimization of micro-WEDM process parameters for machining Ti49.4-Ni50.6 shape memory alloy (SMA) for orthopedic implant application. Effect of micro-WEDM parameters viz. Gap voltage, capacitance, wire feed and wire tension on the response variables such as material removal rate, surface roughness, kerf width and dimensional deviation is determined. As Ti-Ni SMA has fascinating properties and bio-compatibility, have been considered for present work. Nine experiments have been performed on micro-WEDM based on an orthogonal array of Taguchi method. Subsequently, the grey relational analysis (GRA) method is applied to determine an optimal set of process parameters. It is observed that optimized set of parameters A3B3C3D1 viz. 140 V gap voltage, 0.4 µF capacitance, wire feed 30 µm/sec and 30% of wire tension determined by using GRA offers maximum MRR and minimum SR, KW and DD. From the Analysis of Variance, it is seen that the process parameter capacitance is the most significant parameter for multi-response optimization with a percentage contribution of 77.91%. Young’s modulus also checked for biocompatibility. Also, SEM images are taken to confirm the results offering better surface quality. Heat treatment process like annealing is found to be the most suitable to recover shape memory effect of WEDMed samples.
TL;DR: In this paper, the authors present the results of their research work related to the high cycle fatigue resistance of advanced high strength steels and compare the results with each other and with literary data.
Abstract: The objective of this article is to present the newest results of our research work related to the high cycle fatigue resistance of advanced high strength steels. In order to determine and compare the fatigue resistance, high cycle fatigue (HCF) tests were performed on two strength categories (S690 and S960) of high strength steels including quenched and tempered (Q+T) and thermomechanical (TM) types. During the HCF tests base materials and their welded joints were investigated at different mismatch conditions (matching, undermatching, overmatching). Measured and analysed data about base materials and welded joints were compared and discussed. Statistical approach was applied during the preparation and the evaluation of the investigations, which increased their reliability. The parameters of the HCF design curves were calculated based on the Japanese testing method (JSME S 002-1981) which uses 14 specimens. During the evaluation the results were compared with each other and with literary data. According to the presented examinations the HCF resistance of the base materials is more advantageous than the welded joints. The TM steel indicated better fatigue resistance than the quenched and tempered one of the same category. The matching problem had influence on the HCF resistance of high strength steels, depending on the strength category and the steel type.
TL;DR: In this paper, the authors focused on the study of improvement on physical and mechanical properties of cement mixed clay, and showed that the specific gravity of all samples are linearly vary with cement content.
Abstract: Deformation due to load from the construction of infrastructure in soft ground is high and sometimes also becomes problematic. There are various techniques to strengthen the ground among which, the most suitable and commonly used method is chemical stabilization using cement. This method is fast and cement is relatively cheap, abundant and efficient. This research is focused on the study of improvement on physical and mechanical properties of cement mixed clay. Soil sample from Kathmandu, Nepal is taken for the laboratory investigations. The soil is reconstituted by using Ordinary Portland Cement of 5%, 10%, and 15% by its mass. The study revealed that physical and mechanical characteristics of cemented clay are greatly improved for engineering purposes. The specific gravity of all samples are linearly vary with cement content. Similarly, the liquid limit and plastic limit of clay are increased with increased cement content. However, hydraulic conductivity of the soils is decreased with the increase in cement content i.e. reduction is almost 7.5 times when cement increases from 5% to 15%. Finally, cohesion is increased from 3.23 kPa to 67.89 kPa in contrast to friction component which is decreased from 19.58° to 18.56°. Therefore, shear strength of clay is improved due to improvement on cohesion property of clay because of the reduction in the thickness of the diffused doubled-layer of adsorbed water.
TL;DR: In this paper, the influence of laser drilling process on microstructural changes along with the geometrical characteristics are analyzed and discussed in the Nimonic 263 sheets, thickness of 2 mm, are laser drilled with various parameters.
Abstract: Nimonic 263 is an alloy with superior mechanical strength and creep resistance at high temperatures and pressure, good formability, and corrosion and oxidation resistance. Due to their high beam density and very short pulses which reduces the heat affected zone (HAZ) Nd:YAG lasers are very suitable for materials drilling. In this paper, the Nimonic 263 sheets, thickness of 2 mm, are laser drilled with various parameters. The influence of laser drilling process on microstructural changes along with the geometrical characteristics are analysed and discussed.
TL;DR: Based on the basic truck axle structure design, revised designs with thickness-reduced were proposed to reduce the weight of truck axle.Both basic and modified design were modeled using Abaqus 3D software to calculate the stress and strain contours in the case of vertical load and axial torque, then fatigue life contours of models for each load case were calculated with the help of Brown-Miner biaxial fatigue theory as discussed by the authors.
Abstract: Struck axle is a critical component of truck that bears the auto-body weight and load weight. Fatigue life safety is the primary consideration in the design process of axle. With the development of environmental protection concept of energy saving and emission reduction, lightweight design of vehicles becomes more and more urgent. It has been becoming a mainstream trend for design to ensure both safety and significantly reduce the weight of axle. Based on the basic truck axle structure design, revised designs with thickness-reduced were proposed to reduce the weight of truck axle .Both basic and modified design were modeled using Abaqus 3D software to calculate the stress and strain contours in the case of vertical load and axial torque, then fatigue life contours of models for each load case were calculated with the help of Brown-Miner biaxial fatigue theory. It was shown by the research that topology-optimization of truck axle, under a premise of qualified fatigue life and stiffness required by customers, can reduce the weight of two kinds of truck axles by 15.3% and 18.1% respectively.
TL;DR: In this paper, the authors focused on determining the effect of process parameters like laser power, scanning speed, layer thickness and hatch spacing on the hardness of CL50WS (maraging18Ni300 steel) material.
Abstract: The aim of the this study to determine optimal process parameter for the hardness of direct metal laser sintering (DMLS) process as the hardness plays a significant role in to DMLS made components and die or mould. In this manner, research is focused around determining the effect of process parameters like laser power, scanning speed, layer thickness and hatch spacing on the hardness of CL50WS (maraging18Ni300 steel) material. A response surface methodology based numerical model was proposed to predict hardness, and the adequacy of the created model was checked through the analysis of variance technique. Additionally, optimized conditions were set up to maximize the hardness through the desirability function theory.
TL;DR: In this paper, the authors compare the evolution of temperature, tensile strength, elongation and microscopic aspect with the linear position on the joint (local process parameters) for each experimental case and then make comparisons between them, and to identify and present the set of process parameters that has the best mechanical properties for this material.
Abstract: Welding copper and its alloys is usually difficult to achieve by conventional fusion welding processes because of high thermal diffusivity of the copper, which is at least 10 times higher than most steel alloys, in addition to this, there are the well-known disadvantages of conventional fusion welding represented by necessity of using alloying elements, a shielding gas and a clean surface. To overcome these inconveniences, Friction Stir Welding (FSW), a solid state joining process that relies on frictional heating and plastic deformation, is being explored as a feasible welding process. In order to achieve an increased welding speed and a reduction in tool wear, this process is assisted by another one (TIG) which generates and adds heat to the process. The research includes two experiments for the FSW process and one experiment for tungsten inert gas assisted FSW process. The process parameters that varied were the rotational speed of the tool [rpm] and the welding speed [mm/min] while the compressive force remained constant. The purpose of this paper is to correlate the evolution of temperature, tensile strength, elongation and microscopic aspect with the linear position on the joint (local process parameters) for each experimental case and then make comparisons between them, and to identify and present the set of process parameters that has the best mechanical properties for this material.
TL;DR: In this article, the authors provide an overview of the comparison of different types of Natural Fiber Composites, factors that affect the mechanical, thermal and machinabilty of NFCs and their engineering applications.
Abstract: Recently, there has been an exponential growth in research and innovation in the natural fiber composites (NFC) due to their diversified applications in the field of engineering. Biodegradability, light weight, formability and availability at low cost are the attractive merits of the natural fibers. Mechanical, Thermal and Machinabilty properties of Natural fiber composites have their own advantage and adoptability in the field of automobile, power plants, aeronautical, defense and naval applications. This review aims to provide an overview of the comparison of differ types of Natural fiber composites, factors that affect the mechanical, thermal and machinabilty of NFCs and their engineering applications.
TL;DR: In this article, the authors investigate the mechanical properties of a hybrid combination of a banana-pineapple natural fiber reinforced epoxy hybrid composites and compare the results with pure banana and pure Pineapple.
Abstract: The aim of this paper is to investigate the mechanical properties of Banana-Pineapple natural fiber reinforced epoxy hybrid composites. The hybrid combination of fibers with various weight fractions i.e. (40/0, 30/10, 20/20, 10/30 and 0/40) are incorporated into the epoxy LY556 and HY951and hand layup technique is used for fabrication. Initially fibers are cut to a length of 5mm and weight percentagesare determined. Banana fiber was hybridized with Pineapple fiber. While overall fiber weight fraction was fixed as 0.4Wf. Tensile, Flexural and Impact specimens are prepared according to ASTM standards. The Dog-bone shaped specimens are prepared for tensile test. Tensile testing was conducted on 5 ton universal testing machine (FIE Make). Flat bar and V-notch shaped specimens are prepared for conducting Flexural, Impact tests.The results are compared with pure Banana and pure Pineapple. Tensile, Flexural and Impact properties of Hybrid Composites are improved as compared to pure composites. The interfacial relationships between the fiber and matrix, internal cracks, fiber pullout, fiber dispersion into the matrix and the inner surfaces of the specimens are examined through SEM analysis.
TL;DR: In this article, the authors designed and completed the different polymer dosage of recycled concrete, was prepared by adding amount was 7, 14, 21, 14% styrene butadiene latex recycled concrete and ordinary concrete block.
Abstract: This paper designed and completed the different polymer dosage of recycled concrete, was prepared by adding amount was 7%, 14%, 21%, 14% styrene butadiene latex recycled concrete, recycled rubber powder recycled concrete and ordinary concrete block, the cube compressive strength and damping performance test. The cube compressive strength of concrete test according to the ordinary concrete mechanics performance test methods, specimen is 150×150×150 mm cube specimens, pressure testing machine loading speed is 0.5 MPa per second. The concrete damping performance test is carried out according to the free attenuation method, with the hammer vibration test device, the test piece is T type. Based on the damage form of specimens, the compressive strength and damping performance analysis, and compared with ordinary concrete as the benchmark analysis test results show that the polymer recycled concrete cube compressive strength failure process and failure pattern basic consistent with common concrete. In the water/cement ratio, sand ratio, and amount of material per unit volume is the same, under the condition of polymer recycled concrete cube compressive strength is lower than normal concrete, damping performance is higher than that of ordinary concrete, the compressive strength is inversely proportional to the damping sexual relations.
TL;DR: In this article, the effect of heat treatment of AZ91 magnesium alloy, for different durations at 400 °C, prior to electroless Ni-P deposition on corrosion resistance was investigated.
Abstract: Magnesium alloys are excellent choice for automobile, aerospace, and computer components owing to their light weight, unique physical and mechanical properties. However, poor corrosion resistance has restricted their applications in aggressive environments. The surface coating is one of the viable options to reduce the susceptibility of magnesium alloys to corrosion. The present study focuses on the effect of heat treatment of AZ91 magnesium alloy, for different durations at 400 °C, prior to electroless Ni-P deposition on corrosion resistance. The microstructure and elemental analysis of the heat-treated specimens are performed using SEM and EDS techniques respectively. It is observed that the duration of heat treatment has a significant effect on the surface morphology and microstructure of the alloy. The precipitates in the cast alloy (enriched with Mg and Al) fragmented and the transformed into a new Al and Zn rich phase, after 12 h heat treatment. The dissolution of precipitates, however, observed on heating further to 24 h and exhibited relatively a lesser corrosion current density. The dense electroless Ni-P deposition is formed on the alloy heat treated for 24 h. The corrosion behavior of the single Ni-P layer on the heat treated (for 12 h) and untreated alloy show a marked deterioration, as investigated by the anodic polarization and electrochemical impedance spectroscopy (EIS) techniques. Relatively a better corrosion performance is seen for the double-layer Ni-P deposition. The duplex layer coatings on the as cast and heat treated for 24 h at 400 °C substrates showed an improved corrosion resistance compared to that on the 12 h heat treated substrate.
TL;DR: In this article, the thermal properties of Zirconium have been studied and the authors concentrated on variation of Coefficient of Thermal Expansion by varying temperatures by using Dilatometer and as well as ANSYS.
Abstract: Zirconium alloys are solid solutions of zirconium or other metals. Zirconium has very low absorption cross-section of thermal neutrons. Zirconium has high corrosion resistance, ductility and hardness. Zirconium is mainly used as a good refractory metal. Zirconium can be manufactured by using standard fabrication techniques. In the present scenario zirconium alloys are used in water reactors for the cladding of fuel rods in nuclear reactors in nuclear technology. We use the composition of zirconium alloys as more than 94.5 weight percentage of zirconium and less than 2.45 weight percentage of copper which are added to improve mechanical, thermal properties and corrosion resistance. This paper first focuses on the study of thermal properties of Zirconium. And this particularly concentrated on variation of Coefficient of Thermal Expansion by varying temperatures by using Dilatometer and as well as ANSYS