scispace - formally typeset
Search or ask a question

Showing papers in "Journal of materials research and technology in 2020"


Journal ArticleDOI
TL;DR: In this article, the AA7050 aluminium alloy is used as a base material with reinforcement of Silicon Carbide (SiC) at various percentage level like 0, 4 % and 6 %.
Abstract: Aluminium alloy is the popular material in the world to produce lot of light weight parts with high strength, in additionally reinforcement is consider to these alloy is improve its strength. In this investigation consider the AA7050 aluminium alloy as a base material with reinforcement of Silicon Carbide (SiC) at various percentage level like as 0%, 4 % and 6 %. The wear of this composites are analysed through the design of experiments (Taguchi approach) for optimize the process parameters. This wear study is considered the parameters are Sliding velocity in m/s (1, 2 and 3), Sliding distance in m (1000, 1400 and 1800) and percentage of composition (0%, 43% and 6%). For this experimental investigation the sliding distance as most significant factor among three. The microstructure analysis demonstrated that there is a SiC particles which reduces wear of the samples.

345 citations


Journal ArticleDOI
TL;DR: In this article, various monitoring methods for tool condition monitoring in the milling process that have been practiced and described in the literature have been summarized and described. But, the most important improvement in metal the cutting industry is the continuous utilization of cutting tools and tool condition monitor system.
Abstract: The most important improvement in metal the cutting industry is the continuous utilization of cutting tools and tool condition monitoring system. In the metal cutting process, the tool condition has to be administered either by operators or by online condition monitoring systems to prevent damage to both machine tools and workpiece. Online tool condition monitoring system is highly essential in modern manufacturing industries for the rising requirements of cost reduction and quality improvement. This paper summaries various monitoring methods for tool condition monitoring in the milling process that have been practiced and described in the literature.

191 citations


Journal ArticleDOI
TL;DR: In this article, the effect of minimum quantity lubrication (MQL), cryogenic cooling with liquid nitrogen (LN2) and hybrid-CryoMQL methods on tool wear behavior, cutting temperature, surface roughness/topography and chip morphology in a turning operation was investigated.
Abstract: Although nickel-based aerospace superalloys such as alloy 625 have superior properties including high-tensile and fatigue strength, corrosion resistance and good weldability, etc., its machinability is a difficult task which can be solved with alternative cooling/lubrication strategies. It is also important that these solution methods are sustainable. In order to facilitate the machinability of alloy 625 with sustainable techniques, we investigated the effect of minimum quantity lubrication (MQL), cryogenic cooling with liquid nitrogen (LN2) and hybrid-CryoMQL methods on tool wear behavior, cutting temperature, surface roughness/topography and chip morphology in a turning operation. The experiments were performed at three cutting speeds (50, 75 and 100 m/min), fixed cutting depth (0.5 mm) and feed rate (0.12 mm/rev). As a result, CryoMQL improved surface roughness (1.42 µm) by 24.82% compared to cryogenic cooling. The medium level of cutting speed (75 m/min) can be preferred for the lowest roughness value and lowest peak-to-valley height when turning of alloy 625. Further, tool wear is decreased by 50.67% and 79.60% by the use of MQL and CryoMQL compared with cryogenic machining. An interesting result that MQL is more effective than cryogenic machining in reducing cutting tool wear.

176 citations


Journal ArticleDOI
TL;DR: In this paper, Pentaglycidyl ether pentabisphenol A of phosphorus (PGEPBAP) phosphorus polymer was investigated as corrosion inhibition for carbon steel in aggressive solution using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss (WL), scanning electron microscope (SEM), density functional theory (DFT), electrostatic potential (ESP), radial distribution function (RDF), molecular dynamics (MD) and Monte Carlo (MC) simulations.
Abstract: Pentaglycidyl ether pentabisphenol A of phosphorus (PGEPBAP) phosphorus polymer was investigated as corrosion inhibition for carbon steel in aggressive solution using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss (WL), scanning electron microscope (SEM), density functional theory (DFT), electrostatic potential (ESP), radial distribution function (RDF), molecular dynamics (MD) and Monte Carlo (MC) simulations. The higher inhibition efficiencies for PDP, EIS and WL studies at 10−3 M concentration of PGEPBA phosphorus polymer are 94.18 %, 91.79 % and 91.3 %, respectively. ΔEcorr (23.7 mV) value of PGEPBAP phosphorus polymer is lower than 85 mV has been assigned to mixed type inhibitor. PGEPBAP formed protective film on carbon steel surface by adsorption according to Langmuir adsorption isotherm. SEM morphology suggested that PGEPBAP could effectively block acid attack by chemisorption on metal surface. To evaluate the polymer inhibitor and potential mechanism were especially realized DFT, ESP, RDF, MD and MC simulations.

171 citations


Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the factors that affect heavy metal adsorption onto industrial effluents using industrial solid waste (ISW), such as contact time, temperature, pH, and adsorbent dose.
Abstract: Industrial solid waste (ISW) is the waste obtained from the industrials activities which include any solid materials that are rendered useless during a manufacturing process. The ISW considers a global environmental problem and serious solutions must be taken to face this problem and decrease its environmental load and impact. Adsorption of heavy metal from industrial effluents using ISW is considered as a promising, potential and inexpensive alternative concept for ISW management. The ISW offering potential advantages as the zero cost, availability, high efficiency, and green alternative source. Heavy metals adsorption onto ISW is a complex process that affected by several factors including initial metal ions concentration, contact time, pH of the solution, temperature and adsorbent dose. In this paper, we review the factors that affect heavy metal adsorption onto ISW, such as contact time, temperature, pH, and adsorbent dose. The chief findings of the present review are: (1) The heavy metal ions removal% is high at the initial stage of the adsorption process then it decreases till it reaches equilibrium. (2) Temperature greatly affects the heavy metal adsorption process. (3) There is a definite pH value for each metal ion, at which the extreme adsorption of those metal ions occurs. (4) Increasing adsorbent dose generally increases catalytic activity due to the increase in the total surface area and the number of active places on the surface of the adsorbent. Knowing the factors that affect heavy metal adsorption onto ISW will help in optimizing the condition for heavy metal adsorption onto ISW.

169 citations


Journal ArticleDOI
TL;DR: In this article, Al-Si-Mg is employed as matrix material and silicon nitride (Si3N4) particles as reinforcement material to manufacture the aluminum composites (AMCs).
Abstract: In the current research study, AA6351 (Al-Si-Mg) is employed as matrix material and silicon nitride (Si3N4) particles as reinforcement material to manufacture the aluminum composites (AMCs). AA6351 matrix composites incorporated with several weight fractions of Si3N4 (0, 1, 2 and 3 wt.%) were synthesized via stir casting technique. The obtained composites were characterized through a scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). EDS and XRD spectrums demonstrate the presence of Si3N4 reinforcement contents in the manufactured AMCs. The SEM analysis exhibits the even dissemination of Si3N4 particles in the Al alloy. The mechanical properties of the composites are examined by conducting several kinds of tests like compression test, impact test, tensile test and hardness test to understand the relationship between the weight percentages of reinforcement on the mechanical characteristics of the manufactured AMCs. The un-lubricant tribological characteristics of the proposed AMCs were assessed utilizing pin on disk tribometer. The hardness, compression and tensile strength of the AMCs were augmented concerning the mass proportion of reinforcement content. Finally, the wear test result reveals that the addition of nano-sized Si3N4 reinforcement contents up to a mass proportion of 3% downgrades the wear rate.

144 citations


Journal ArticleDOI
TL;DR: In this article, the studies conducted on metal matrix composites, in which graphene was used as reinforcing material, were investigated and the properties of the produced composites were presented and the factors affecting these properties were explained.
Abstract: Graphene, on which numerous studies have been conducted since its discovery, exhibits extra-ordinary properties unlike conventional materials. Owing to these properties, graphene has a great potential usage in many applications and also can be used as reinforcing material in different composite materials. The use of graphene as reinforcing materials in metal matrix composite materials allows to develop new generation composites, as well. Numerous studies on metal matrix graphene reinforced composites have been conducted within the last ten years. Different studies have determined various properties in the graphene reinforced composites having the same metal matrix. This is caused by many factors such as the production method of the composite, production method of the graphenes, matrix/graphene interface, distribution of the graphenes and the orientation of the graphene in the matrix. By the optimization of these factors and simplifying and improving the production methods, the graphene reinforced metal matrix composites have great potential to be used in many applications. In this paper, the studies conducted on metal matrix composites, in which graphene was used as reinforcing material, were investigated. In these studies, the properties of the produced composites were presented and the factors affecting these properties were explained.

134 citations


Journal ArticleDOI
TL;DR: In this article, the effects of using polyethylene terephthalate (PET) as a partial substitute for sand in concrete were examined and the experimental results showed a reduction in unit weight, the sand replacement harmed the concrete mechanical properties at varying rates and proved that plastic waste can be disposed of by specific ratios and therefore can be effectively applied in industrial usage.
Abstract: Solid waste is one of the many factors that negatively affect the environment. Problems stem from factors such as difficulty of waste recycling and limited reuse. Plastic is an important type of solid waste with a strong environmental impact. This study aims to investigate the effects of utilising poly-ethylene terephthalate (PET) as a partial substitute for sand in concrete. The effects of this material on the physical and mechanical properties of concrete were examined. A group of six concrete mixtures containing PET was prepared as a partial substitute for sand with substitution levels 0%, 10%, 20%, 30%, 40% and 50%. Concrete was cast to determine the behaviour of fresh and hardened concrete in terms of workability, unit weight, compressive strength, flexural strength, tensile strength, pulse velocity and fire-resistant behaviour. The experimental results showed a reduction in unit weight, the sand replacement harmed the concrete mechanical properties at varying rates and proved that plastic waste can be disposed of by specific ratios and therefore, can be effectively applied in industrial usage.

133 citations


Journal ArticleDOI
TL;DR: Pang et al. as mentioned in this paper investigated the adsorption mechanism of Cr(VI) on GO-Fe3O4 based on natural graphite made from kusambi wood from Timor Island, Indonesia.
Abstract: Graphene oxide material has been studied widely as a novel adsorbent due to its unique surface structures, excellent physicochemical properties, strong affinity and high efficiency for the metal ions adsorption [Pang H, Wu Y, Wang X, Hu B, Wang X. Recent advances in composites of graphene and layered double hydroxides for water remediation: a review. Chem - Asian J 2019;14:2542–52; Liu X, Ma R, Wang X, Ma Y, Yang Y, Zhuang L, et al. Graphene oxide-based materials for efficient removal of heavy metal ions from aqueous solution: a review. Environ Pollut 2019;252:62–73]. The present report involves Cr(VI) adsorption studies using graphene oxide-magnetic (GO-Fe3O4) based on natural graphite made from kusambi wood from Timor Island, Indonesia. GO with large specific surface area and abundant functional groups was synthesized using Hummers modification method, while GO-Fe3O4 was synthesized using in situ co-precipitation method. Characterization of GO and GO-Fe3O4 material was carried out using FTIR, XRD and SEM-EDX. The maximum adsorption capacity is optimum at the use of 0.1 g adsorbent GO-Fe3O4, under conditions: pH 2 with contact time for 80 min and temperature of 298 K. Nine kinetic models, five ishotherm models and two adsorption thermodynamics were used to study the mechanism of Cr(VI) adsorption on the surface of GO-Fe3O4. The results of kinetics and isotherms modeling show that the adsorption mechanism of Cr(VI) on GO-Fe3O4 follows pseudo-second (PSO) order kinetics with a high regression coefficient (>0.99) and was well described by Langmuir isotherm with adsorption capacity of 3.197 mg/g. The thermodynamics data revealed the exothermic nature, a decrease in the randomness or irregularity on the surface of adsorbent during adsorption process and takes place through physisorption. Studies on isosteric enthalpy values show that the adsorption of Cr(VI) on the surface of GO-Fe3O4 is strongly influenced by the amount of adsorbate which tends to decrease in adsorption capacity as the amount of Cr(VI) ions increases.

123 citations


Journal ArticleDOI
TL;DR: In this article, the AISI D2 cold work tool steel, a material widely used in the mold industry, was used as the workpiece and experiments were carried out using two different cutting tool coating types (CVD-chemical vapor deposition and PVD-physical vapor deposition) and three different cutting speeds (60, 90 and 120m/min) at a constant cutting depth (1 mm) and feed rate (0.09
Abstract: Today, developments in technology have gained momentum more than ever, and the need for efficiency in production as well as in the ecological domain has increased significantly. Studies examining dry machining and coolant removal have been superseded by those presenting new cooling and lubrication techniques. The effects on surface roughness directly related to final product quality are being investigated in terms of tool life and employee health. This has resulted in more frequent use of the eco-friendly minimum quantity lubrication (MQL) technique, which has now become a major competitor to dry and coolant machining. In this study, AISI D2 cold work tool steel, a material widely used in the mold industry, was used as the workpiece. Tests were carried out under dry and MQL conditions and the temperature, cutting tool vibration amplitude, tool wear, surface roughness and tool life were evaluated. The experiments were carried out using two different cutting tool coating types (CVD-chemical vapor deposition and PVD-physical vapor deposition) and three different cutting speeds (60, 90 and 120 m/min) at a constant cutting depth (1 mm) and feed rate (0.09 mm/rev). Results revealed that tool wear, cutting temperature and cutting tool vibration amplitude were lower by 23, 25, and 45%, respectively, compared to dry cutting. Because of these improvements, the surface roughness of the workpiece was improved by 89% and tool life was increased by up to 267%.

121 citations


Journal ArticleDOI
TL;DR: In this article, the authors summarize the recent progress in FSW of aluminium-magnesium alloys and recommend the upcoming guidance concerning to fabrication of aluminum-mag magnesium alloys through FSW.
Abstract: At present aluminium-magnesium alloys are widely used in various engineering applications due to its light weight and superior properties. Joining is considered as one of the most complex phenomenon in various precision industries like aerospace, railway, automotive and marine structures because inflexible tolerances are required during different product assembly. The friction stir welding (FSW) of aluminium-magnesium of various grade has incited substantial scientific and industrial importance since it has a potency to transform the product with a good quality joint. The fabrication of such alloys is a challenging task through conventional fusion welding due to its various metallurgical concerns. Therefore, the present work is intended to summarize the recent progress in FSW of aluminium-magnesium alloys. Particular attention has been paid to microstructural evolution, phase transformation, recrystallization mechanism, material flow behaviour and how the process parameters influence the various mechanical properties and associated defects during FSW. Various experimental and numerical simulation results have been mentioned for weld property comparison. Finally, this work not only points out the prominent conclusions of the preceding research but also recommends the upcoming guidance concerning to fabrication of aluminium-magnesium alloys through FSW.

Journal ArticleDOI
TL;DR: In this paper, the effects of alkaline treatment and hybridization on the thermal properties of sugar palm yarn/glass fiber were investigated, and the results showed that a higher glass fiber loading hybridized with treated sugar palm fiber exhibited the highest storage modulus, loss modulus and the lowest damping factor.
Abstract: In this work, the effects of alkaline treatment and hybridization on the thermal properties of sugar palm yarn/glass fiber were investigated. The sugar palm fiber was treated with 1% of sodium hydroxide (NaOH) solution for 1 h and the ratio of between matrix and reinforcement was 70/30 wt.% and 60/40 wt.%, respectively, while the ratio of reinforcement between sugar palm yarn fiber and glass fiber was 70/30 wt.%, 60/40 wt.% and 50/50 wt.%, respectively. The thermal properties of the hybrid composites were analyzed using a dynamic mechanical analyzer (DMA) and Thermogravimetric analysis (TGA). The storage modulus (E'), loss modulus (E") and damping factor (tan δ) were evaluated as a function of the alkaline treatment and different percentages of fiber loading. Also, the peak high was investigated for the tan δ curves. In the glassy state area, a higher glass fiber loading hybridized with treated sugar palm fiber exhibited the highest storage modulus, loss modulus and the lowest damping factor. TGA demonstrated that the percentage of residue decreased as the glass fiber loading increased. Overall, the hybridization of glass fiber with treated sugar palm fiber enhances the thermal properties of the hybrid composites for structural applications.

Journal ArticleDOI
TL;DR: In this paper, a thermal conductivity model of nanofluids involving static and dynamic approach is considered, which signifies hydrodynamic interaction among the Brownian motion induced fluid particles.
Abstract: Background Characterised with augmented heat transport and thermal efficiency, nanofluids are implementable in diversified applications include pharmaceutical industries, hybrid-powered machines, cooling of different appliances, refrigerator, microelectronic, heat exchanger etc. Taking such advantages into mind, physical aspects of entropy optimization and non-linear thermal radiation in Darchy–Forchheimer flow of copper–water nanofluid due to a rotating disk are examined. A new thermal conductivity model of nanofluids involving static and dynamic approach is considered. This model signifies hydrodynamic interaction among the Brownian motion induced fluid particles. The Cattaneo–Christov heat flux theory is taken into account. The second law of thermodynamics is the instrumental for the determination of total entropy generation rate. Methods The system of nonlinear PDEs is converted into system of nonlinear ODEs through favorable transformations. Shooting technique has been applied prospectively to accomplish the desired numerical solution of the transformed equations. Results The behavior of velocity (axial, transverse and tangential) and thermal fields influenced by varied physical parameters is impressed through graphs and numerical tables. Velocity field peters out due to rising porosity parameter as well as volume fraction while thermal field upgrades for higher Biot number and radiation parameter. Significant heat transfer rate is obtained for smaller estimation of radiation parameter. Entropy generation rate and Bejan number exhibit similar trend for radiation parameter and opposite fashion for Reynolds number. Conclusions The diminishing velocity distribution for larger access of porous matrix while elevated temperature distribution for higher temperature parameter (due to nonlinear thermal radiation). Entropy minimization is accomplished for grater estimation of Brinkman and Reynolds numbers.

Journal ArticleDOI
TL;DR: A survey of the state-of-the-art of laser and electron beam powder bed fusion, 3D printing design, development, fabrication and applications of porous, or open-cellular metal and alloy personalized implants is presented in this paper.
Abstract: This overview presents a survey of the state-of-the-art of laser and electron beam powder bed fusion, 3D printing design, development, fabrication and applications of porous, or open-cellular metal and alloy personalized implants; and is particularly directed to materials and biomaterials students and professionals. Of particular importance is the application of metallurgy principles, especially the role played by traditional solidification fundamentals, in predicting and characterizing the microstructures and mechanical properties of additively manufactured implants representing a host of human skeletal reconstruction and replacement appliances. In addition to presenting important reviews highlighting very recent metallurgical processing strategies and current trends in the global development of hospital point-of-care, 3D printing centers creating surgical planning models in association with the fabrication of personalized, patient-specific implants are described.

Journal ArticleDOI
Abstract: Wood and composites cantilever beam structure has gained attention among researchers in the current years due to its universal structural applications, such as bridges, aeroplane wings, buildings, and transmission towers. However, when the structure is exposed to a constant loading for a very long time, it induces a structural collapse due to creep deformation. Therefore, it is essential to understand and identify the initial creep that can lead to structural collapse. In this study, wood and composite materials exhibit the same structural material morphology which performs as anisotropic material as it majorly contributes to failure. In this study, a state-of-the-art review of creep analysis and engineering design is carried out, with particular emphasis on the creep methodology of a cantilever beam. The existing theories and creep design approaches are grouped into two analysis methods, namely experimental and numerical approaches. To be more specific, the experimental works involved two main methods, namely load-based (conventional) and temperature-based (accelerated) techniques. Selected creep test on cantilever beam structure and coupon scale of wood and composite were highlighted and proposed as the building blocks for a prospective structural creep methodology. These aids build confidence in the underlying methods while guiding future work and areas, especially for long-term service of full-scale structure. At the end, the challenges of creep behaviour description accuracy and improvement on the strength criteria in engineering design were presented.

Journal ArticleDOI
TL;DR: In this article, the partial replacement of volcanic pumice powder (VPP) for use as a supplementary cementitious material was investigated for use in high-strength concrete mixtures, and several tests, including slump, compressive strength, indirect tensile strength, flexural strength, water absorption, initial surface absorption and sorptivity, were conducted to evaluate HSC performance.
Abstract: In this paper, the partial replacement of volcanic pumice powder (VPP) was investigated for use as a supplementary cementitious material. High-strength concrete (HSC) was prepared using two sets of VPP (10% and 20%) incorporated with three sets of polypropylene fiber (PF) (0.20%, 0.35%, and 0.50%) to produce different concrete mixtures. Several tests, including slump, compressive strength, indirect tensile strength, flexural strength, water absorption, initial surface absorption, and sorptivity, were conducted to evaluate HSC performance. Results showed the prepared specimens with 10% cement replacement with VPP and 0.20% PF content indicated a slight increase in compressive strength compared with the control concrete at later ages. Indirect tensile and flexural strengths were optimized at 10% VPP replacement with 0.50% PF content. Furthermore, adding PFs to mixes increased indirect tensile and flexural strength but decreased slump. The sorptivity test indicated low water soaking due to VPP content in the mixes compared with the control mix (HSC); it declined as the replacement of VPP increased. The different standard tests on mixes depicted favorable results and good prospects for the inclusion of VPP in HSC structures.

Journal ArticleDOI
TL;DR: In this article, an artificial neural network (ANN) was used to estimate the surface roughness based on cutting speed, cutting tool, workpiece, depth of cut and feed rate.
Abstract: This study examined the hard turning of AISI D2 cold work tool steel subjected to deep cryogenic processing and tempering and investigated the effects on surface roughness and tool wear. In addition, the effects of the deep cryogenic processes on mechanical properties (macro and micro hardness) and microstructure were investigated. Three groups of test samples were evaluated: conventional heat treatment (CHT), deep cryogenic treatment (DCT-36) and deep cryogenic treatment with tempering (DCTT-36). The samples in the first group were subjected to only CHT to 62 HRc hardness. The second group (DCT-36) underwent processing for 36 h at −145 °C after conventional heat treatment. The latter group (DCTT-36) had been subjected to both conventional heat treatment and deep cryogenic treatment followed by 2 h of tempering at 200 °C. In the experiments, Al2O3 + TiC matrix-based untreated mixed alumina ceramic (AB30) and Al2O3 + TiC matrix-based TiN-coated ceramic (AB2010) cutting tools were used. The artificial intelligence method known as artificial neural networks (ANNs) was used to estimate the surface roughness based on cutting speed, cutting tool, workpiece, depth of cut and feed rate. For the artificial neural network modeling, the standard back-propagation algorithm was found to be the optimum choice for training the model. Three different cutting speeds (50, 100 and 150 m/min), three different feed rates (0.08, 0.16 and 0.24 mm/rev) and three different cutting depths (0.25, 0.50 and 0.75 mm) were selected. Tool wear experiments were carried out at a cutting speed of 150 m/min, a feed rate of 0.08 mm/rev and a cutting depth of 0.6 mm. As a result of the experiments, the best results for both surface roughness and tool wear were obtained with the DCTT-36 sample. When cutting tools were compared, the best results for surface roughness and tool wear were obtained with the coated ceramic tool (AB2010). The macroscopic and micro hardness values were highest for the DCT-36. From the microstructural point of view, the DCTT-36 sample showed the best results with homogeneous and thinner secondary carbide formations.

Journal ArticleDOI
TL;DR: In this article, the synthesis, structural characteristics and magnetism of hard and soft nanocomposites were reported, and the hard/soft compositions were manufactured via a one-pot reactions citrate sol-gel approach.
Abstract: This paper reports the synthesis, structural characteristics and magnetism of SrFe12O19/MCe0.04Fe1.96O4 (M = Cu, Ni, Mn, Co and Zn) hard/soft nanocomposites. The hard/soft compositions were manufactured via a one-pot reactions citrate sol-gel approach. The hard/soft phases formation was confirmed using XRD, SEM, TEM and HRTEM techniques. M vs. H (Magnetization measurements) were done at unbent temperature and 10 K. Smoothed M against H loops and single peaks in dM/dH vs. H curves were noticed in SrFe12O19/MnCe0.04Fe1.96O4, SrFe12O19/CuCe0.04Fe1.96O4 and SrFe12O19/ZnCe0.04Fe1.96O4 hard/soft nanocomposites. This indicated the manifestation of well exchange-coupled effect among hard and soft phases in these composites. However, SrFe12O19/CoCe0.04Fe1.96O4 and SrFe12O19/NiCe0.04Fe1.96O4 hard/soft nanocomposites showed non-well smoothed M against H loops and two peaks in dM/dH versus H plots, indicating that the dipolar interactions are unimportant compared to exchange-coupling behavior. Among all prepared nanocomposites, the SrFe12O19/MnCe0.04Fe1.96O4 hard/soft nanocomposite showed the highest exchange-coupling behavior. Microwave properties of the SrFe12O19/MCe0.04Fe1.96O4 (M = Cu, Ni, Mn, Co and Zn) hard/soft nanocomposites were investigated using coaxial method with applied frequency values fall between 2 and 18 GHz. Reflection losses were calculated from frequency dependences of the imaginary and real parts of permeability and permittivity. The correlation between the chemical composition of the spinel phase (A-cation) and microwave properties of composites. Most intensive electromagnetic absorption was observed for Ni- and Mn-spinels. This is can be a result of the differences in electron shell configuration and radii for A-site ions in the spinel phase. Change of the absorption mechanisms (transition from ionic polarization to dipole polarization) was observed.

Journal ArticleDOI
TL;DR: In this article, the second order velocity slip nonlinear entropy optimized Darcy-Forchheimer flow of ferrofluid (FF) is developed towards a stretched surface and the energy equation is discussed in the presence of heat source/sink, dissipation and Ohmic heating or Joule heating.
Abstract: Ferrofluids are made out of nanoscale ferromagnetic particles and known as colloidal liquids suspended on a bearer liquid, normally water (H2O) or an organic solvent i e., kerosene. A typically composition would be 5% magnetic particles, 10% surfactant and 85% bearer liquid. Ferrofluid is utilized in rotary seals in computer hard drives, loudspeakers, and MRI (magnetic resonance imaging). It is trusted this research work may explore the specialist to think of consider new uses for this attractive material. Therefore, such effectiveness in mind, mathematical modeling for the second order velocity slip nonlinear entropy optimized Darcy–Forchheimer flow of ferrofluid (FF) is developed towards a stretched surface. The energy equation is discussed in the presence of heat source/sink, dissipation and Ohmic heating or Joule heating. Numerical solutions for the desired ordinary system are contracted via built-in shooting method. The flow parameters are discussed graphically.

Journal ArticleDOI
TL;DR: In this article, a comprehensive review of the sustainability of additive manufacturing, from the circular economy and recycling of materials to other environmental challenges involving the safety of materials and manufacturing, is presented.
Abstract: This research is a comprehensive review of the sustainability of additive manufacturing, from the circular economy and recycling of materials to other environmental challenges involving the safety of materials and manufacturing. There has been important progress in this area, with an increasing number of papers that cover diverse environmental aspects, including the circular economy, recycling and the life cycle assessment of materials. This increase is due to the importance that scientists, industry, government and society are now giving to these topics. This review seeks to develop a greater awareness in relation to the possibilities and implications in the use of the AM, as well as to encourage sustainable development by raising awareness in relation to the taking of necessary actions to achieve compliance of the Sustainable Development Goals. Similarly, current trends are examined in relation to the practices that are currently being adopted in order to ensure that AM is consolidated as a sustainable and convenient practice in the economic, social and environmental spheres. In general, polymers, ceramics, metals and composite materials are now undergoing intensive research to improve their use. Although this research shows that significant progress has been made on several relevant issues, using materials optimization to minimize energy and waste is still far from a global solution.

Journal ArticleDOI
TL;DR: In this paper, the effect of ultrasonication duration on the properties of PVA film was studied and it was shown that the effects of the duration of the ultrasonic probe on the tensile strength and tensile modulus and strain at the break of the PVA gel increased by almost 29 %.
Abstract: Many works reported a PVA based film prepared using ultrasonication, however, information on the effect of this treatment on changes of PVA’s properties is still limited. The main objective of this work was to study the effect of ultrasonication duration on the properties of PVA film. The PVA gel was sonicated using a 360 W ultrasonic probe for 2.5, 5, 7.5 and 10 min. Ultrasonication duration for 7.5 min results in a significant effect (p ≤ 0.05) on an increase in tensile strength, but not on tensile modulus and strain at the break of the film. After this vibration duration, tensile strength increased by almost 29 %, strain at break decreased by 30 %, opacity decreased by 22 %, and water vapor permeability decreased by 11 %. On the other hand, moisture resistance decreased significantly (almost 12 %). The sonicated film underwent larger lattice strain and had higher crystal structure compared to non-sonicated film. This work informs that ultrasonication on PVA gel is a potential method to fulfil some properties of PVA film for food packaging material.

Journal ArticleDOI
TL;DR: In this article, a Cryogenic cooling with external MQL lubrication (CryoMQL) working along with CO2 as internal coolant is proposed for milling Inconel 718 with the aim of not only improving from a technical point of view but also environmental.
Abstract: Machining Inconel 718 alloy is a challenge due to its low machinability. This thermal resistant alloy combines high strength even at high temperatures with strain hardening tendency that causes high forces and extreme cutting temperatures during the machining. These issues force industries to achieve suitable machining processes to deal with this kind of alloys and the high worldwide competitiveness. Nevertheless, environmental considerations must to be taken into account due to growing environmental concerns. In the work here presented, cryogenic cooling with external MQL lubrication (CryoMQL) working along with CO2 as internal coolant is proposed for milling Inconel 718 with the aim of not only improving from a technical point of view but also environmental. This technique was compared with other lubricooling techniques. The results show that internal CryoMQL improves tool life by 57% in comparison with emulsion coolant, achieving 120% if it is compared with MQL in stand-alone mode.

Journal ArticleDOI
TL;DR: In this article, the strength characteristics of geopolymer self-compacting concrete made by addition of mineral admixtures, have been modelled with both genetic programming (GEP) and the artificial neural networks (ANN) techniques.
Abstract: There has been a persistent drive for sustainable development in the concrete industry While there are series of encouraging experimental research outputs, yet the research field requires a standard framework for the material development In this study, the strength characteristics of geopolymer self-compacting concrete made by addition of mineral admixtures, have been modelled with both genetic programming (GEP) and the artificial neural networks (ANN) techniques The study adopts a 12M sodium hydroxide and sodium silicate alkaline solution of ratio to fly ash at 033 for geopolymer reaction In addition to the conventional material (river sand), fly ash was partially replaced with silica fume and granulated blast furnace slag Various properties of the concrete, filler ability and passing ability of fresh mixtures, and compressive, split-tensile and flexural strength of hardened concrete were determined The model development involved using raw materials and fresh mix properties as predictors, and strength properties as response Results shows that the use of the admixtures enhanced both the fresh and hardened properties of the concrete Both GEP and ANN methods exhibited good prediction of the experimental data, with minimal errors However, GEP models can be preferred as simple equations are developed from the process, while ANN is only a predictor

Journal ArticleDOI
TL;DR: In this article, an attempt to synthesis titanium dioxide (TiO2) doped zinc oxide (ZnO) composite via Pulsed Laser Ablation in Liquids (PLAL) and study its antibacterial properties was made.
Abstract: This article attempt to synthesis titanium dioxide (TiO2) doped zinc oxide (ZnO) composite via Pulsed Laser Ablation in Liquids (PLAL) and study its antibacterial properties. The structure, optical, morphological of the prepared composite have been investigated via various technique. FT-IR results confirm existence of TiO2 doped ZnO. XRD measurements approved the enhanced crystallinity ZnO after doped by TiO2 via PLAL technique. The optical transmittance was enhanced from 78.6% of pure ZnO to 92.3% for TiO2 doped ZnO. TEM images of ZnO showed an obvious elongated rod-like shapes that were rectangular or hexagonal and spherical particles. Moreover, the cell viability has been studied for the papered pure ZnO and TiO2 doped ZnO. The minimum cell viability ratio was about 81.4 ± 4.2% for pure ZnO and was increased to 91.6 ± 5.1% for TiO2 doped ZnO. The antibacterial activity of the samples that measured via MIZ approved that the TiO2 doped ZnO make a raise in the activity index. It was suggested that TiO2 doped ZnO can be used in many antimicrobial application.

Journal ArticleDOI
TL;DR: In this article, the role of copper nanoparticles on modifying polyethylene oxide (PEO)/polyvinyl pyrrolidone (PVP)/Copper Oxide Nanoparticles (CuONPs) was demonstrated.
Abstract: Polyethylene Oxide (PEO)/Polyvinyl pyrrolidone (PVP)/Copper Oxide Nanoparticles (CuONPs) were synthesized by one-step Pulsed Laser Ablation of pure Copper plate immersed in PEO/PVP (70/30 wt.%) solution. PEO/PVP/CuONPs composite films were prepared using casting method. The role of copper nanoparticles on modifying PEO/PVP was demonstrated. The effect of different laser ablation times on the characterization of the prepared PEO/PVP/CuONPs composite films have been studied via XRD, UV–vis, PL, SEM, and Ac conductivity. XRD and SEM confirm the complexation between CuONPs and PEO/PVP matrix. The appearance of the characteristic absorption peak at 275 nm in UV–vis spectrum was attributed to the surface plasmon resonance (SPR) of CuONPs. The values of the direct and indirect optical band gap show a decreasing after doping PEO/PVP matrix by CuONPs. PL analysis confirmed that the existence of the CuO nanoparticles comprehensively reorders the delocalized n-electron system of PEO/PVP blend matrix. The behavior of dielectric constant and dielectric loss are progressively decreased as the frequency increased. The values of AC conductivity are increased as the laser ablation time increased. M ' and M″ values are increased by increasing the concentration of CuONPs in the PEO/PVP blend matrix, which induces an increase in the ion conduction of the prepared samples.

Journal ArticleDOI
TL;DR: In this article, the authors present a review of the impact of hole quality on the performance of the Al2024 and Al7075 alloys used in the aerospace industry, focusing mainly on the hole size and circularity error.
Abstract: Despite the growth of composites and other lightweight materials, aluminium alloys remain an attractive choice of the aerospace industry due to their mature manufacturing processes, good resistance to fatigue crack growth and superior damage tolerance. In the aerospace industry, the drilling process is the most challenging among all the other machining process as millions of holes are required for producing riveted and bolted joints in the assembly operation of the aircraft's structures. The major challenges which arise from the drilling of these alloys are characterized by the poor hole quality which might initiate cracks within the airframe structure and reduces their reliability. This results in the rejection of parts at the assembly stage which directly impacts the manufacturing cost. Hence, appropriate selection of tool geometry, tool material and coatings, optimal cutting speed and feed rate, as well as drilling machines, is required to meet the requirement of machined parts. This motivates both academia and industries to further research on the application of drilling operations in the aircraft industry. This review aims to document details on drilling forces, drilling parameters, drill tool geometry, drill materials and coatings, chips formation, analysis of tool wear and hole metrics such as the hole size and circularity error, surface roughness, and burrs formation during the drilling of different aluminium alloys used in the aerospace industry. The focus will be mainly on Al2024 and Al7075 alloys since they are most commonly used and reported in the open literature.

Journal ArticleDOI
TL;DR: In this article, the effect of heat treatments on the microstructural and mechanical properties of the alloys and parameters affecting this heat treatment efficiency are analyzed for metastable β titanium alloys.
Abstract: Metastable β titanium alloys are widely used in the biomedical, automotive, and aerospace industry, due to their excellent corrosion resistance, fatigue strength, biocompatibility, and easy formability. Besides all these use areas, the suitable microstructure of the alloys for heat treatment increases the efficient usability day by day. In literature research, it has been found that heat treatment types such as cryogenic treatment and precipitation hardening can be applied efficiently to the alloys. Optimum strength/ductility, wear resistance, creep strength, and fatigue strength can be obtained with these heat treatments. For this reason, it has become important to understand the effect of heat treatments on the microstructural and mechanical properties of the alloys and parameters affecting this heat treatment efficiency. Precipitation hardening includes solution and aging treatment steps. The solution treatment can be applied at temperatures below and above the β transition temperature. While the aging treatment can be applied in four different ways, in the review article, the effects of single step and duplex aging treatment, which are applied with high efficiency, are emphasized. Precipitation hardening efficiency affects the chemical composition of the alloys, heat treatment steps, treatment temperature and times, and heating/cooling rate. The cryogenic treatment provides the formation of martensite α phases in metastable β titanium alloys cooled below the martensitic transformation temperature. Higher-strength and hardness have been obtained in the studies where aging treatment was applied after cryogenic treatment. Cryogenic treatment efficiency determines chemical composition of the alloys, treatment temperature and time, the heating/cooling rates, and heat treatments applied after cryogenic treatment.

Journal ArticleDOI
TL;DR: In this paper, a Ni-WC coating was fabricated successively on a copper substrate by laser and the microstructure, hardness and wear resistance were investigated, and the experimental results show that this NiWC coating has a good metallurgical bonding strength and hardness, and it also has good wear resistance and high temperature property, which is helpful to improve the service life of mould copper plate.
Abstract: A Ni-WC coating was fabricated successively on a copper substrate by laser. The microstructure, hardness and wear resistance were investigated. The thickness of Ni-WC coating was 0.65 mm and average hardness of strengthening layer was 667HV0.1, which was approximately 7.8 times higher than the hardness of copper substrate. The wear volume of Ni-WC coating was only 0.014 mm3, which was only 1.02% wear volume of copper substrate. The decrease in wear volume was mainly due to presence of reinforced phases, such as γ-Ni, Cr0.19Fe0.7Ni0.11, M7C3, M23C6 and WC. In addition, there was no coating peeled off after 100 times trials of heat shock resistance experiment at 800℃. The experimental results show that this Ni-WC coating has a good metallurgical bonding strength and hardness, and it also has good wear resistance and high temperature property, which is helpful to improve the service life of mould copper plate.

Journal ArticleDOI
TL;DR: An overview of the evolution of graphene oxide synthesis routes (GOSR) can be found in this article, where the authors provide an incentive to produce novel green methods for large scale production of GOSR.
Abstract: Herein, we provide an overview of the evolution of graphene oxide synthesis routes (GOSR). The oxidation of grapheneentails the applications of oxidizing agents which may affect the process parameters, synthesis and purity of graphene oxide. The utilization of potential oxidants has commonly reported for large scale production of graphene oxide. Traditional synthesis approaches have been limited by the properties of oxidizing reagents. Recently, various improved and modified Hummers methods (IHM/MHM) have emerged. The strengths and limitations of the conventional techniques have reported. Synthetic processes and characterization techniques have stated for the scale up synthesis of graphene oxide. This review could possibly provide the motivation to produce novel green methods for large scale production of graphene oxide.

Journal ArticleDOI
TL;DR: In this article, the stability analysis of a non-linear shrinking sheet is examined in the presence of viscous dissipation and suction/injection effects, where the governing equations of mathematical models are transformed into selfsimilar solutions in the form of ODEs by using similarity transformation.
Abstract: Researchers are using different types of nanomaterials for the enhancement of the thermal performance of regular fluids such as water, kerosene oil, etc. However, these days, the researchers are more interested in hybrid nanomaterials. The purpose of this communication is to examine the stability analysis of Cu–Al2O3/water hybrid nanofluid over a non-linear shrinking sheet. The hybrid nanomaterials are composed of Cu and Al2O3. These hybridized nanomaterials are then dissolved in water taken as base fluid to form Cu–Al2O3//water hybrid nanofluid. Mathematical analysis and modeling have been attended in the presence of viscous dissipation and suction/injection effects. The governing equations of mathematical models are transformed into self-similar solutions in the form of ODEs by using similarity transformation. Solutions of the non-linear ODEs are created by employing of three-stage Lobatto IIIa formula which is built-in BVP4C function in the MATLAB software. A comparison of the current study has been done with the preceding published literature. The distributions of velocity, temperature profiles, coefficient of skin friction and heat transfer rate are presented graphically and conferred for numerous significant parameters entering into the problem. Results revealed the existence of dual solutions for a certain range of the suction/blowing parameter. Stability analysis is also done in order to obtain dual solutions stability. The smallest eigenvalues suggest that the first solution is stable from the second solution. Hybrid nanomaterials have a high scope toward nurturing our day-to-day life.