Showing papers in "Materials and Manufacturing Processes in 2015"
TL;DR: In this article, the main focused aim of developing new processing and manufacturing technologies are to reduce production or manufacturing costs, processing times, and to enhance manufactured product properties, and the developed processing techniques should be widely acceptable for all types of materials including metal matrix composites, ceramics, alloys, and fiber reinforced plastics.
Abstract: The main focused aim of developing new processing and manufacturing technologies are to reduce production or manufacturing costs, processing times, and to enhance manufactured product properties. The developed processing techniques should be widely acceptable for all types of materials including metal matrix composites, ceramics, alloys, and fiber reinforced plastics. Microwave materials processing is emerging as a novel processing technology which is applicable to a wide variety of materials system including processing of MMC, FRP, alloys, ceramics, metals, powder metallurgy, material joining, coatings, and claddings. In comparison to the conventional processes, microwave processing of materials offers better mechanical properties with reduced defects and economical advantages in terms of power and time savings. The present review work focuses mainly on global developments taking place in the field of microwave processing of materials and their relevant industrial applications.
278 citations
TL;DR: In this article, the authors reviewed various minimum quantity lubrication (MQL) methods used by various machining processes for different materials and highlighted the future work directions for research in this area.
Abstract: In the pursuit toward achieving dry cutting, air machining, minimum quantity lubrication (MQL), and cryogenically cooled machining are the stepping stones. Nevertheless, machining is always accompanied by certain difficulties, and hence none of these methods has provided a complete solution. Hence, this article reviews various MQL methods used by various machining processes for different materials. It also highlights the future work directions for research in this area.
208 citations
TL;DR: A colloidal mixture of nanometer-sized (<100nm) metallic and non-metallic particles in conventional cutting fluid is called nanofluid and is considered to be potential heat transfer fluids as discussed by the authors.
Abstract: A colloidal mixture of nanometer-sized (<100 nm) metallic and non-metallic particles in conventional cutting fluid is called nanofluid. Nanofluids are considered to be potential heat transfer fluids because of their superior thermal and tribological properties. Therefore, nano-enhanced cutting fluids have recently attracted the attention of researchers. This paper presents a summary of some important published research works on the application of nanofluid in different machining processes: milling, drilling, grinding, and turning. Further, this review article not only discusses the influence of different types of nanofluids on machining performance in various machining processes but also unfolds other factors affecting machining performance. These other factors include nanoparticle size, its concentration in base fluid, lubrication mode (minimum quantity lubrication and flood), fluid spraying nozzle orientation, spray distance, and air pressure. From literature review, it has been found that in nanofluid ...
154 citations
TL;DR: In this article, a multi-criteria decision-making method (MCDM) was applied to an AWJ cutting process with multiresponse characteristics using the Technique for Order Preference by Similarity Ideal Solution (TOPSIS) approach.
Abstract: This paper describes how optimization studies were carried out on an abrasive water jet (AWJ) cutting process with multiresponse characteristics based on Multi Criteria Decision Making Methodology (MCDM) using the Technique for Order Preference by Similarity Ideal Solution (TOPSIS) approach. The process parameters water jet pressure, traverse rate, abrasive flow rate, and standoff distance are optimized with multiresponse characteristics, including the depth of penetration (DOP), cutting rate (CR), surface roughness (Ra), taper cut ratio (TCR), and top kerf width (TKW). The optimized results obtained from this approach indicate that higher DOP and CR and lower Ra, TCR, and TKW were achieved with combinations of the AWJ cutting process parameters, such as water jet pressure of 300 MPa, traverse rate of 120 mm/min, abrasive flow rate of 360 g/min, and standoff distance of 1 mm. The experimental results indicate that the multiresponse characteristics of the AA5083-H32 unit used during the AWJ cutting process...
124 citations
TL;DR: In this article, a review describes the use of plastic film for mulching in water-efficient agriculture practices with special reference to progress made in degradable film materials, including water efficient mechanisms and techniques of mulching film cultivation.
Abstract: The dramatic increase in plastic film mulching in water-efficient agriculture is primarily due to its versatile nature that has proven to be very beneficial over the last decade in the arid region. However, as carelessly used plastic mulch films lead to agro-environmental pollution, there has been vigorous research recently to develop degradable film materials for mulching. This review describes the use of plastic film for mulching in water-efficient agriculture practices with special reference to progress made in degradable film materials. Moreover, this review includes water-efficient mechanisms and techniques of mulching film cultivation, photodegradable and biodegradable plastic polymers (PHA, PCL etc. synthetic- and natural-based polymers films), their degradation process and developmental deficiencies, and an outlook of degradable film materials. There exists great potential for the further development of water-efficient agriculture; however, it is dependent upon effective research and the wide-spec...
118 citations
TL;DR: In this article, an improvement in material removal rate (MRR) is explored using tungsten powder suspended dielectric fluid in EDM process (powder-mixed electrical discharge machining (PMEDM)).
Abstract: In the present work, aluminum alloy 6061/10%SiC composite is machined using numerical controlled Z-axis (ZNC) electrical discharge machining (EDM) process. Improvement in material removal rate (MRR) is explored using tungsten powder suspended dielectric fluid in EDM process (powder-mixed electrical discharge machining (PMEDM)). Peak current, pulse on time, pulse off time, and gap voltage are studied as process parameters. Mathematical relation between process parameters and MRR is established on basis of response surface methodology. The results obtained are further compared with MRR achieved from machining using simple EDM. The existence of tungsten particles in kerosene resulted in 48.43% improvement in MRR. The influence of tungsten powder-mixed dielectric fluid on machined surface is analyzed using scanning electron microscope and energy dispersive spectroscopy (EDS). The results revealed improvement in surface finish and reduction in recast layer thickness with PMEDM. EDS analysis reported presence o...
110 citations
TL;DR: In this paper, the machining characteristics of Inconel 718 by wire-EDM and Sinking-EDm with a new Cu-SiC electrode, respectively, have been characterized.
Abstract: Inconel 718 superalloy has wide applications in several industries due to its excellent mechanical properties However, it is very difficult to machine using conventional cutting and grinding because of its high strength at elevated temperatures Electrical discharge machining (EDM) is an alternative competitive process to machine Inconel alloys by electrical erosion However, machinability and surface characteristics of EDMed Inconel surfaces are poorly understood This study focuses on the machining characteristics of Inconel 718 by Wire-EDM and Sinking-EDM with a new Cu-SiC electrode, respectively Material removal efficiency, surface roughness, surface topography, surface alloying, and electrode wear have been characterized It is found that the high toughness of Inconel 718 would be the major contributing factor to the absence of microcracks on the EDMed surface The new fabricated Cu-SiC electrode for Sinking-EDM has better performance in terms of material removal rate (MRR), surface roughness, and
101 citations
TL;DR: In this article, the fabrication of AISI 420 stainless steel using selective laser melting (SLM) for the application of plastic injection molding was investigated, and the microscopic microstructure, phase composition, and hardness were characterized using scanning electron microscopy, X-ray diffraction, and Rockwell hardness test, respectively.
Abstract: Selective laser melting (SLM) offers great possibilities to fabricate metal tools with a complex geometry, but there are limitations regarding some materials. This work focuses on the fabrication of AISI 420 stainless steel using SLM for the application of plastic injection mold. The melt characteristic of the powders was firstly concluded, and then the microstructure, phase composition, and hardness were characterized using scanning electron microscopy, X-ray diffraction, and Rockwell hardness test, respectively. The results showed that cellular microstructure was observed along the direction of the maximum heat flow. The proportion of the phases varies with the change of SLM processing parameters, which directly affects on the hardness of the parts. The relative density over 99% was obtained and the highest hardness presents 50.7 HRC, which meets the requirement of plastic injection molding application.
83 citations
TL;DR: In this article, the effects of Mg particle size and processing parameters on the properties of SLM specimens were investigated and the scan speed and laser power were optimized based on macro-observation of the forming process and resulted specimens.
Abstract: In this study, bulk net-shape pure magnesium was fabricated by selective laser melting (SLM). Effects of Mg particle size and processing parameters on the properties of SLM specimens were investigated. The scan speed and laser power were optimized based on macro-observation of the forming process and resulted specimens. Through the comparison analysis of topology, density, and micro-hardness, it was found that the bulk magnesium specimen made of −250 mesh powder showed better results than that made of −400 mesh powder. The relative densities of both SLM specimens were over 95%, and their micro-hardness values were higher than that of as-cast magnesium. It was also revealed that the scanning time interval (STI), as a relatively new processing parameter, had an obvious effect on the properties of SLM bulk magnesium in terms of surface morphology, roughness, and micro-hardness.
75 citations
TL;DR: In this paper, an attempt was made to investigate the influence of copper tool vibration with ultrasonic frequency on output parameters in the electrical discharge machining of Ti-6Al-4V.
Abstract: In this research, an attempt was made to investigate the influence of copper tool vibration with ultrasonic frequency on output parameters in the electrical discharge machining of Ti–6Al–4V. The se...
69 citations
TL;DR: In this article, the influence of melt and die temperatures on the squeeze cast silicon carbide particulate reinforced aluminum alloy composites was investigated. But the results revealed significant influence of both melt and dies on the mechanical properties.
Abstract: The paper deals with the influence of melt and die temperatures on the squeeze cast silicon carbide particulate reinforced aluminum alloy composites. Samples were produced at the following constant melt and die temperatures: melt—750, 800, 850, and 900°C; die—250, 300, 350, and 400°C. During the specimen fabrication, pressure was maintained at 100 MPa. The results reveal significant influence of both melt and die temperatures on the mechanical properties. The optimum melt and die temperatures for the preparation of the composite are 850°C and 350 °C, respectively. Tensile and impact strengths, and hardness of composite samples prepared at this temperature combination are found to be better than those of samples prepared at other temperatures. Additionally, microstructures of samples prepared at this temperature combination display a relatively fine grain structure and the smallest degree of particle agglomeration which explain the dependence of mechanical properties on the melt and die temperatures.
TL;DR: In this paper, the physical, mechanical properties and dry turning performance of AlTiN, AlTiCrN, and TiN/TiAlN coatings produced on K-grade tungsten carbide insert by advanced physical vapor deposition technique were presented.
Abstract: This study presents the physical, mechanical properties and dry turning performance of AlTiN, AlTiCrN, and TiN/TiAlN coatings produced on K-grade tungsten carbide insert by advanced physical vapor deposition technique. Scanning electron microscopy, microhardness tester, and scratch tester were used to examine surface morphology, coating thickness, microstructure, microhardness, and adhesion of coating. The performance in terms of cutting force and temperature of AlTiN, AlTiCrN, and TiN/TiAlN coated inserts was evaluated while dry turning of SS 304 steel. SS 304 is considered as “difficult-to-cut” material due to its exotic properties. The experiments were conducted at cutting speed of 140, 200, 260, and 320 m/min. Feed and depth of cut were kept constant and their values were 0.20 mm/rev and 1 mm, respectively. Experimental observations depicts that AlTiCrN coated insert demonstrated better performance because of its good adhesion and high oxidation resistance followed by TiN/TiAlN coated insert. TiN/TiAl...
TL;DR: In this paper, the effect of TiO2 activated flux on penetration is evaluated for different workpieces namely AISI 1020, aISI 304, A ISI 316, and Duplex 2205 steels at different currents and shielding gas compositions.
Abstract: In tungsten inert gas (TIG) welding, limited depth of penetration can be achieved during single pass welding. To achieve the desired depth of penetration, the speed of welding needs to be significantly reduced and hence, the productivity decreases. In the present work, the effect of TiO2 activated flux on penetration is evaluated for different workpieces namely AISI 1020, AISI 304, AISI 316, and Duplex 2205 steels at different currents and shielding gas compositions. The results show a significant increase in the depth of penetration and reduction in the width-to-penetration ratio using the activated flux for all the workpiece materials considered here. Current increases the depth of penetration, however, the influence of flux becomes more significant with higher welding current. Maximum of 37.8%, 44.3%, 47%, and 124% increase in depths of penetration is measured for AISI 1020, AISI 304, AISI 316, and Duplex 2205 steels, respectively, when activated flux is used. Also, maximum of 70% increase in the depth...
TL;DR: In this paper, the authors investigated different welding processes such as laser beam, resistance, tungsten inert gas, friction stir, submerged arc, and plasma arc weldings considering the research available in the literature.
Abstract: Duplex stainless steels (DSSs) have many advantages due to the unique structural combination of ferrite and austenite grains. The structural change of these materials is very complex during welding, and it deteriorates the functional properties. This research investigates different welding processes such as laser beam, resistance, tungsten inert gas, friction stir, submerged arc, and plasma arc weldings considering the research available in the literature. The welding mechanism, change of material structure, and control parameters have been analyzed for every welding process. This analysis clearly shows that DSS melts in all most all welding processes, but the thermal cycle and maximum heat input are different. This difference affects the resulting structure and functional properties of the weld significantly.
TL;DR: In this paper, the influence of cutting speed (Vc) (51, 84, and 124 m/min) on various machining characteristics like chip morphology, chip thickness ratio, tool wear, surface, and sub-surface integrity during dry turning of Inconel 825.
Abstract: In the current study, attempt has been made to investigate the influence of cutting speed (Vc) (51, 84, and 124 m/min) on various machining characteristics like chip morphology, chip thickness ratio, tool wear, surface, and sub-surface integrity during dry turning of Inconel 825. Comparable study was carried out using uncoated and commercially available chemical vapor deposition multilayer coated (TiN/TiCN/Al2O3/ZrCN) cemented carbide (ISO P30 grade) insert. Chip morphology consists of chip forms obtained at different cutting conditions. Serrated chips were observed when machining Inconel 825 with both types of tool with more serration in case of uncoated insert. The chip thickness ratio increased as cutting speed was increased. Use of multilayer coated tool also resulted in increase in chip thickness ratio. Rake and flank surfaces were examined with scanning electron microscope and optical microscope. Abrasion, adhesion, and diffusion wears were found to be dominating tool wear mechanism during dry machi...
TL;DR: In this article, the authors investigated the technical feasibility of using a low power continuous wave carbon dioxide laser for removing the top resin layer of carbon fiber reinforced polymer (CFRP) composites.
Abstract: The removal of top resin layer is an essential task prior to adhesive bonding of carbon fiber reinforced polymer (CFRP) composites. This paper investigates the technical feasibility of using a low power continuous wave carbon dioxide laser for removing the top resin layer of CFRP without damaging the underlying fiber. The operating window and damaging threshold were experimentally determined. Irradiating the CFRP surface at a power of 14 W, scanning speed of 880 mm/sec, and a beam overlap of 25% provides an optimal thermal condition for removal of top resin layer. A finite element model was used to explain the removal mechanisms.
TL;DR: Abrasive flow machining (AFM) is an advanced finishing process as discussed by the authors, and it is of upmost importance that these processes can be applied to composite materials as these have replaced traditional materials in many applications.
Abstract: In the era of nontraditional finishing processes, it is of upmost importance that these processes can be applied to composite materials as these have replaced traditional materials in many applications. Abrasive Flow Machining (AFM) is an advanced finishing process. Composite materials have replaced traditional materials as their properties such as light weight, high strength, and good economy are of great benefit. In the literature, work has been reported on AFM of materials such as aluminum, brass, and EN8. In the present work, composite materials with a high percentage of SiC (e.g., 20–60% SiC in Al/SiC composites) were machined using abrasive flow finishing. The Taguchi method was applied to find the effect of input parameters on material removal rate (MRR), change in surface roughness (ΔRa), and surface topography, and L27 array was designed for experimentation. It was observed that extrusion pressure is the most significant factor in regard to MRR and ΔRa. Optimization of response parameters (MRR an...
TL;DR: In this article, a ball end magnetorheological finishing (BEMRF) process was developed for finishing a flat as well as 3D workpiece surfaces, which is mainly finished by abrasives contained in MRP fluid.
Abstract: A ball end magnetorheological finishing (BEMRF) process was developed for finishing a flat as well as 3D workpiece surfaces. The BEMRF process has a wide scope in today's advanced manufacturing systems for finishing 3D complex surfaces. Magnetorheological (MR) polishing fluid is used as finishing medium in BEMRF process. The constituent of MR polishing (MRP) fluid includes ferromagnetic carbonyl iron powder, abrasives, and base fluid medium. The workpiece surface is mainly finished by abrasives contained in MRP fluid. Therefore, the different mesh size from 400 to 1200 and volume percent concentration from 5% to 25% of abrasives in MRP fluid were chosen as factors to study their effects on the developed process performance in terms of percent change in roughness values. Silicon carbide abrasives were chosen in the present experimental investigation. Experiments were performed on the ferromagnetic ground surfaces whose initial roughness values (Ra) were measured in the range of 0.428 to 0.767 µm. The exper...
TL;DR: In this paper, a direct precipitation method was developed for the facile and efficient synthesis of ZnWO4 nanoparticles, which can be fine-tuned through adjustment of the reaction parameters, including zinc and tungstate ion solution concentrations and the reaction temperature.
Abstract: The study involves a direct precipitation method developed for the facile and efficient synthesis of ZnWO4 nanoparticles. Effects of various parameters such as zinc and tungstate ion solution concentrations, flow rate of reagent addition, and reactor temperature on diameter of synthesized zinc tungstate nanoparticles were investigated experimentally by the aid of orthogonal array design. The findings of the study revealed that the diameter of the produced ZnWO4 nanoparticles can be fine-tuned through the adjustment of the reaction parameters, including zinc and tungstate ion solution concentrations and the reaction temperature, and at optimum conditions of synthesis procedure, the size of the produced zinc tungstate particles was about 33 nm. Finally, scanning electron microscopy, X-ray diffraction, FTIR, and photoluminescence techniques were used for structural and morphological characterization of the product, so as to monitor the role of the mentioned parameters on the targeted properties in the product.
TL;DR: A Kriging based surrogate model has been proposed to replace a computationally expensive model to save execution time while performing an optimization task and solutions similar to those found by the first principle models are obtained.
Abstract: Despite the established superiority in finding the global as well as well-spread Pareto optimal (PO) points, the need of more numbers of function evaluations for population based evolutionary optimization techniques leads to a computationally demanding proposal. The case becomes more miserable if the function evaluations are carried out using a first principle based computationally expensive model, making the proposal not fit for online usage of the application. In this work, a Kriging based surrogate model has been proposed to replace a computationally expensive model to save execution time while performing an optimization task. A multi-objective optimization study has been carried out for the bulk vinyl acetate polymerization with long-chain branching using these surrogate as well as expensive models and Kriging PO solutions similar to those found by the first principle models are obtained with a close to 85% savings in function evaluations.
TL;DR: In this paper, the thermally induced phase separation (TIPS) technique was used for the fabrication of three-dimensional porous chitosan and hydroxyapatite (HA)/chitosans composite scaffolds for bone tissue engineering.
Abstract: This article reports the fabrication of three-dimensional porous chitosan and hydroxyapatite (HA)/chitosan composite scaffolds by the thermally induced phase separation (TIPS) technique, for bone tissue engineering. Different amounts of HA nanoparticles (10%, 20%, and 30% g/g) were added to the chitosan solution to produce HA/chitosan composite scaffolds of varying compositions. The morphology and pore structure of the scaffolds vis-a-vis composition were characterized using scanning electron microscopy (SEM) and an energy dispersive X-ray (EDX). Both pure chitosan and HA/chitosan composite scaffolds were highly porous and had interconnected pores. The pore sizes ranged from several micrometers to a few hundred micrometers. The HA nanoparticles were well dispersed and physically coexisted with chitosan in the composite scaffolds. However, some agglomeration of HA nanoparticles was observed on the surface of pore walls when a relatively large amount of HA was used. The composite 3D scaffolds are very promi...
TL;DR: In this article, the influence of different flux powders in the activated-TIG welding process of the Incoloy 800H super alloy was investigated, and it was found that the SiO2 flux could increase the depth of penetration whereas a ZnO flux was detrimental to this effect.
Abstract: This work attempts to investigate the influence of different flux powders in the activated-TIG welding process of the Incoloy 800H super alloy. Three different fluxes (SiO2, ZnO, and 50% ZnO +50% SiO2) were used and welded under the same conditions and process parameters. The oxide fluxes used were in the form of nanoparticle powders. The metallurgical characteristics and mechanical properties were analyzed, and it was found that the SiO2 flux could increase the depth of penetration whereas a ZnO flux was detrimental to this effect. Although a SiO2 flux increased the depth of penetration, it led to a sensitization issue in the grain boundary. The combination of the fluxes 50% ZnO +50% SiO2 produced a moderate increase in the depth of penetration compared to ZnO flux-coated weldments, but revealed a dendritic structure in the weld region.
TL;DR: In this paper, predictions of machining induced microhardness and grain size are performed by using 3D finite element (FE) simulations of machined surfaces of Ti-6Al-4-V alloys.
Abstract: Titanium and its alloys are today used in many industries including aerospace, automotive, and medical device and among those Ti–6Al–4 V alloy is the most suitable because of favorable properties such as high strength-to-weight ratio, toughness, superb corrosion resistance, and bio-compatibility. Machining induced surface integrity and microstructure alterations size play a critical role in product fatigue life and reliability. Cutting tool geometry, coating type, and cutting conditions can affect surface and subsurface hardness as well as grain size. In this paper, predictions of machining induced microhardness and grain size are performed by using 3D finite element (FE) simulations of machining and machine learning models. Microhardness and microstructure of machined surfaces of Ti–6Al–4 V are investigated. Hardness measurements are conducted at elevated temperatures to develop a predictive model by utilizing FE-based temperature fields for hardness profile. Measured hardness, grain size, and fractions ...
TL;DR: In this article, a mixture of boron carbide and graphite ceramic powders with a theoretical composition of 50% each by weight were mechanically alloyed in a laboratory ball mill with different milling times of 12.5, 25, 50, 75, and 100h.
Abstract: In the present research work, the mixture of boron carbide and graphite ceramic powders with a theoretical composition of 50% each by weight were mechanically alloyed in a laboratory ball mill with different milling times of 12.5, 25, 50, 75, and 100 h. The investigation was carried out on the morphologies and densities of ball-milled powders. Morphology results revealed that ball milling is a very dominant and dynamic practice for preparation of two different powders into single entity powder having appropriate and consistent morphology. The results of density measurement showed that with milling times, density increased initially and then reduced with further increase in milling times. The density is reduced by 1.68% as the milling time increased from 0 to 100 h.
TL;DR: In this article, a vibrating module was attached to a classical burnishing tool and was tested on aluminum specimens to find the optimal vibration-assisted burnishing parameters, which resulted in roughness improvements of the specimens and decreased processing time by fivefold compared to traditional burnishing.
Abstract: Burnishing processes are effective methods for treating pieces to increase their durability and roughness. Studies reveal that traditional burnishing can be strongly improved with the assistance of external energy sources. A vibrating module was attached to a classical burnishing tool and was tested on aluminum specimens to find the optimal vibration-assisted burnishing parameters. Vibration caused roughness improvements of the specimens and decreased the processing time by fivefold compared to traditional burnishing. At the tested frequency, no significant consequences were found on hardness and residual stresses.
TL;DR: In this article, a vibration suppression device for thin-walled workpieces is presented based on the electromagnetic induction principle, which utilizes machining vibrations to generate resistant force on the workpiece.
Abstract: Thin-walled workpieces are largely manufactured in the aerospace industry. The manufacturing process has been a problem due to its flexibility, and chatter vibrations are apt to occur, which restricts the machining efficiency and quality. A vibration suppression device for thin-walled workpieces is presented based on the electromagnetic induction principle, which utilizes machining vibrations to generate resistant force on the workpiece. The formulated force varies with the workpiece vibration velocity, but in an opposite direction. Excitation tests using the electromagnetic shaker illustrate that the device is effective in vibration attenuation. Finally, machining tests are carried out with applications to two thin-walled structures for further verification. The machining vibrations and surface quality demonstrate the damping promotion of the workpiece assembly, and milling stability limit is increased by more than twofold.
TL;DR: In this paper, the authors evaluated the influence of different input variables (cobalt content, thickness of workpiece, tool profile, tool material, size of abrasive grains, and power rating) on the hole quality obtained in ultrasonic machining of WC-Co composite material.
Abstract: This study has focused on the evaluation of the influence of different input variables (cobalt content, thickness of workpiece, tool profile, tool material, size of abrasive grains, and power rating) on the hole quality (dimensional and form accuracy) obtained in ultrasonic machining of WC-Co composite material. Taguchi's approach has been employed for planning the experiments and optimization of the experimental results. Three measures of hole quality (hole oversize, out of roundness, and conicity) have been investigated under controlled experimental conditions. The experimental results showed that abrasive grit size and power rating were most influential for the hole quality. Hole quality has been found to be improved at higher cobalt content, whereas it is found to be degraded with the use of coarse grit size.
TL;DR: In this paper, the influence of compaction pressure, sintering temperature, and Sintering time on mechanical and wear behavior of fly ash reinforced copper-based composites are analyzed.
Abstract: In this study influence of compaction pressure, sintering temperature, and sintering time on mechanical and wear behavior of the fly ash reinforced copper-based composites are analyzed. The composites were prepared by powder metallurgy (P/M) technique with copper as matrix, 5 and 10 wt% of fly ash as reinforcement. The green compacts were prepared at three different pressures such as 350, 400, and 450 MPa. The prepared green composites were sintered at 700, 800, and 900 °C for the time period of 30, 60, and 90 min, respectively. From the results it is observed that when the process parameter increases the density, hardness, compression strength, and wear resistance increases.
TL;DR: In this paper, the effects of SiCp treatment and magnesium addition on microstructural and mechanical properties of Al356/20-wt% SiCP semisolid composites were investigated.
Abstract: The effects of SiCp treatment and magnesium addition on microstructural and mechanical properties of Al356/20 wt% SiCp semisolid composites were investigated. The results showed that cleaning and oxidizing of SiCp and addition of 1 wt% Mg resulted in improving wettability, incorporation, and uniform distribution of SiCp in A356 matrix. Consequently, the ultimate tensile strength (UTS) value increased by 19% and 32% when the SiC was treated and also when Mg was added, respectively, compared to as-received SiCp. In addition, hardness value increased from 69.7 HV in as-received SiCp to 94.8 HV after SiCp treatment and addition of Mg.
TL;DR: In this article, the role of carbonyl iron particle (CIP) size on the rheological behavior of the MR polishing fluid under various magnetic flux densities was investigated.
Abstract: The finishing mechanism of the ball-end magnetorheological finishing (BEMRF) process mainly depends on the stiffened hemispheroid, which is formed at the tool tip. Magnetorheological (MR) polishing fluid imparts strength to the polishing spot because of the effect of magnetic field strength. Behavior of this polishing fluid mainly depends on the size and shape of its constituents, volume concentration, particle size distribution, and applied magnetic field strength. A detailed study was undertaken on the role of carbonyl iron particle (CIP) size on the rheological behavior of the MR polishing fluid under various magnetic flux densities. Evaluation of the behavior of MR polishing fluid for silicon polishing was attempted through designing and fabrication of a parallel-plate magnetorheometer. Rheological characterization study was carried out using the Casson fluid model and the MR polishing fluid rheological properties, namely field-induced yield stress and shear viscosity were evaluated.