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During the era of classical languages, classical literature can be seen in the writings of classical authors. There should be maturity in language, character, maturity, principles, broad mind, broad vision, idealism, high generality, dignity, control, discernment, character, clarity, etc. Any literature that is written in a language that does not have a high level of language development, richness, strength, and ability to mould itself according to time will not be considered classical literature. Similar to how the language is nurtured, literature written by such individuals cannot be considered classical literature since they lack character, a broad perspective, and a true heart. In this case, Tamil was a cultural language during the Sangam period. It can be known from its concepts. It is no exaggeration to say that this period was a fertile period for the emergence of classical literature. Among these ancient Sangam works, the Sangam literature accurately described the ancient people's living circumstances in the weaving department, which was divided into five categories. These are divided internally by prioritizing masculinity and femininity and highlighting the personality of the individual. Also in the Sangam literature, there are four that deal with time, soil, and life. They are Kurinji, Mullai, Marutham, Neithal, etc. A specific way of life and culture have been established for each department. Every sector has a distinct culture and way of life. These include textiles that depict coastal life. Additionally, coastal trading began in this area. The aim of this research article is to reveal the life values of the people who lived on this land.

GROMACS is one of the most widely used HPC software packages using the Molecular Dynamics (MD) simulation technique. In this work, we quantify GROMACS parallel performance using different configurations, HPC systems, and FFT libraries (FFTW, Intel MKL FFT, and FFT PACK). We break down the cost of each GROMACS computational phase and identify non-scalable stages, such as MPI communication during the 3D FFT computation when using a large number of processes. We show that the Particle-Mesh Ewald phase and the 3D FFT calculation significantly impact the GROMACS performance. Finally, we discuss performance opportunities with a particular interest in developing GROMACS for the FFT calculations.

This idea deals with the identification of English letters. The input is given to process the character further, it is trained with the computer system modeled on nervous system to identify the design of characters. Pattern identification is one of the effective method used in neural networks. The purpose of neural network is to provide algorithm to recognize the letters. The neural network is given with a target which has the design information; it may be a representation of handwritten data with different size and styles. The neural network will establish the exact given details if it matches with the design that neural network has remembered. This project will be useful in identifying the letters of English and Tamil.

The rain streaks in an image generally cause an imparity in the processing of the image in any image processing algorithm, this is a huge problem under a neural network that would consider these pixels as a part of the image, this might lead to error in the output. To overcome this imparity in images we use the L0 gradient smoothing method to remove the layer of the image, this layer corresponds to the rain pixels, which are typically low amplitude structures and hence removing these pixels by increasing the number of jumps in pixel format causing the overlap of unwanted pixels with much more important pixels and retaining the necessary sharpness of the image. This method also allows the removal of unwanted noise and increases the prediction rate with retention of the structures necessary for processing the image. This method is also useful in removing noise produced in the compression of animated pictures into JPEG format. The removal of rain pixels in any image could improve its processing quality and drastically improve the prediction probability. Finally, after removing these rain pixels, we have an image with low gradient and lower contrast, to improve the contrast and enhance the image we use HOG (Histogram Oriented Gradient System), this allows proper prediction and improves picture quality, this paper also aims at detecting persons in a frame after removal of noise from the input image, thus prediction of people in the given picture is much easier when the HOGS is implemented to it after L0 gradient smoothing is applied.

Rice husk ash (RHA) is an economical and potential reinforcement for producing aluminum matrix composites (AMCs). The present work reports the production and characterization of AA6061/18 vol% RHA AMC using the novel method friction stir processing (FSP). The microstructure was studied using optical microscopy (OM), scanning electron microscopy (SEM) and electron back scattered diagram (EBSD). A homogenous dispersion of RHA particles was obtained in the composite. No agglomeration or segregation was observed. The produced composite exhibited a fine and equiaxed grain structure. RHA particles fragmented during FSP. An improvement in the tensile strength was observed subsequent to reinforcement of RHA particles. The fracture surface was dispersed with fractured RHA particles confirming excellent interfacial bonding with the aluminum matrix.

Friction stir processing (FSP) has been established as a novel solid state technique to produce bulk and surface metal matrix composites. The present work aim to produce copper matrix composites (CMCs) using FSP and analyze the effect of ceramic reinforcement type (SiC, Al 2 O 3 , B 4 C and TiC) on the evolving microstructure, microhardness and wear resistance behavior. A groove was made on 6 mm thick copper plates and packed with various ceramic particles. A single pass FSP was carried out using a tool rotational speed of 1000 rpm, travel speed of 40 mm/min and an axial force of 10 kN. The microstructure and distribution of the ceramic particles were studied using optical and field emission scanning electron microscopy. The sliding wear behavior was evaluated using a pin-on-disk apparatus. The results indicate that the variation in the stir zone, distribution, grain size, hardness and wear resistance of CMCs were within a short range. Nevertheless, Cu/B 4 C CMC exhibited superior hardness and wear resistance compared to other CMCs produced in this work under the same set of experimental conditions.

In the present research, the influence of friction stir welding (FSW) tool material on the mechanical and microstructural properties of friction stir (FS) welded 316L stainless steel butt joints is investigated. FS welds were produced using two different tungsten based FSW tools having identical tool shoulder and pin profiles. In both the cases, the FSW experimental runs were carried out using tool rotational speed of 600 rpm, welding speed of 45 mm/min, axial force of 11 kN and tool tilt angle of 1.5°. The results of the study show that the joints produced using the tungsten lanthanum oxide tool are having superior mechanical and microstructural properties when compared to the joints produced using tungsten heavy alloy tool. Furthermore, the tool degradation study by mass loss and photographic techniques suggests that the tungsten lanthanum oxide tool is more prone to degradation by plastic deformation, whereas the tungsten heavy alloy tool is more prone to degradation by wear.

The requirement of weight reduction, high thermal conductivity and strength at low temperatures and high corrosion resistance has identified the use of Al alloys together with steel in various fields. The use of Al alloys together with steel warrants efficient joining of Al alloys with steels. Friction stir welding (FSW) is a potential candidate for the joining of difficult-to-weld similar and dissimilar materials due to its inherent advantages as a solid state joining process. In order to speed up the research activities that lead to industrial level implementation of FSW of dissimilar Al alloys and steels, modelling and simulation can play a vital role. In this work, a central composite-response surface method (RSM) model is developed to predict the ultimate tensile strength (UTS) of friction stir-welded dissimilar Al alloy AA5052 H32 and HSLA steel IRS M-42-97. The adequacy of the model is verified by the analysis of variance (ANOVA) and computed values of the actual and adjusted R 2 values. The model is validated by the results of experimental trials at parameter combination other than that experimented as per the DOE matrix and found in agreement with an average error of −0.34 %. From the analysis of the developed model, it is observed that the UTS of the joint is very sensitive to the primary FSW parameters, and, as such, the range of primary FSW parameters that could produce significant joint strength is very narrow. Also, it is observed that the tool rotational speed, welding speed and axial force have a significant interaction effect on the UTS of the joint. The analysis of the model and discussion on the effect of FSW parameters on the tensile strength of the joint are supported by the results of scanning electron microscopy and EDS analysis at the joint interface of selected joints.

Friction stir welding provides an alternative method of joining aluminum in a reliable way. Anticipation of the joint efficiency is then a necessary step to optimize the process of the welding operation. In the light of this, artificial neural network (ANN) technique may then be applied as a reliable method for simulating and predicting the durability of the joints for different process parameters. In the present work, an ANN model is presented that predicts the ultimate tensile strength of friction stir-welded dissimilar aluminum alloy joints. Four parameters were considered including tool pin profile (straight square, tapered square, straight hexagon, straight octagon and tapered octagon), rotational speed, welding speed and axial force. Experimental tests were conducted according to a four-parameter five level central composite design. A feed-forward back propagation ANN with a single hidden layer comprising 20 neurons was employed to simulate the ultimate tensile strength (UTS) of the joints. The neural network was trained using the data obtained from the experimental work. A comparison between the experimental and simulated data showed that the ANN model reliably predicted the UTS of dissimilar aluminum alloy friction stir-welded joints. The models developed were capable of predicting values with less than 5 % error. Furthermore, the effect of different process parameters on the tensile behavior of dissimilar joints was also investigated and reported upon.

In the present work 3 mm thick aluminium alloy AA5052 and HSLA steel were successfully butt joined using friction stir welding (FSW) technique. The FSW trials were carried out by varying the tool traverse speed while keeping the other parameters constant. The joint characteristics such as ultimate tensile strength (UTS), microhardness, microstructure at the joint interface and fracture surface of fractured tensile specimens were investigated. SEM and EDS analysis suggest that in all cases intermetallic compound (IMC) layer is formed at the joint interface and its thickness is critical in the tensile strength of the joint. For a given tool rotational speed, axial load and tool tilt angle, the tool traverse speed has significant influence on the thickness of IMC layer formed and hence on the joint strength. The highest joint strength of about 91% of UTS of the base aluminium alloy is obtained at tool traverse speed of 45 mm/min and the UTS follow approximately a centre peak type variation against tool traverse speed.

In the preset investigation, aluminum alloy, AA5052 and HSLA steel are successfully butt welded using a modified FSW process wherein the work pieces submerged in a liquid medium are stirred by the FSW tool. The trials are conducted by varying the tool rotational speed from 400 rpm to 900 rpm while keeping the other parameters constant. The welded joints are tested for ultimate tensile strength (UTS) and the joint interface microstructure is analyzed using SEM and EDS. The results show that when compared to the normal FSW process, the peak value of UTS is marginally low but the range of tool rotational speed that could produce defect free joints with good joint strength is almost doubled in the modified FSW process.

Friction stir processing (FSP) is a novel technique used to fabricate surface composites. This investigation is an attempt to made Al/Al2O3 and Al/SiC surface composite using FSP and compare the mechanical and metallurgical properties influenced by the types of reinforcement particles. Two plates were grooved with 0.8 mm in width, 5 mm in depth and 100 mm in length in the middle of the aluminium plate using wire EDM and compacted with Al2O3 and SiC powder. The FSP was carried out automatically on an indigenously built FSW machine at tool rotational speed of 1200 rpm, processing speed of 60 mm/min and axial force of 10 kN. The optical and Scanning Electron microstructures are precisely revealed the homogeneous distribution of Al2O3 and SiC particles in the stir zone of surface composite layer (SCL). The microhardness was measured across the cross section of SCL layers of Aluminium and Aluminium with SiC and Al2O3. The higher microhardness was obtained in Aluminium with SiC and Al2O3 composites fabricated by FSP. This is because of the higher hardness value of SiC particles than Al2O3 particles.

The present investigation is carried out to investigate on mechanical and metallurgical properties of Friction stir (FS) / Underwater Friction stir (UFS) welded 3 mm thick AISI 316 L stainless steel joints. Experiments were carried out at a tool rotational speed of 700 rpm, welding speed of 45 mm/min and axial force of 12 kN. Defect free joints were confirmed by visual inspection. A marginal rise of about 4.5 % increase in the joint strength is achieved in water cooling than by gas cooling technique. Reduced peak temperature in water cooled joint led to better grain refinement in the weld nugget enhancing FSW tool life. No sign of secondary phase precipitation was observed in the weld joints which was confirmed by Energy Dispersive Spectroscopy (EDS) spectrums and micro etchants like Groesbeck and modified Murakami reagents in the weld nugget.

In the present work, the effect of tool axis offset from the joint interface and geometry of the FSW tool pin on the mechanical and metallographic characteristics of dissimilar friction stir butt welded aluminum (Al) alloy, AA5052 H32 and HSLA steel, IRSM42-93 were investigated. FSW tools having fixed shoulder diameter, pin tip diameter and pin length with three different tapered cylindrical (TC) and one straight cylindrical (SC) tool pin profiles were experimented. The constant FSW parameters used were: tool rotational speed of 500 rpm, welding speed of 45 mm/min, axial load of 7 kN and tool tilt angle of 1.5°. The effect of tool axis offset was investigated by continuously changing the tool axis offset by keeping the tool traverse direction at an angle to the joint interface. The ultimate tensile strength (UTS) of the joint is considered as the main criterion of the joint performance. The results show that the TC pin profile is beneficial and for a given FSW tool geometry and parameters, the taper angle of the tool pin and volume of tool pin penetration into steel side have significant influence on the thickness and composition of the intermetallic compound (IMC) layer formed and hence the joint performance. FSW tool having TC pin with 10° taper angle has produced the best joint at a tool axis offset of 2 mm towards the Al alloy. For the experimented tool pin geometries, the IMC layer formed at the joint interface is consistent with FeAl, Fe2Al5 and FeAl3.

INTRODUCTION: Pseudomonas aeruginosa (P.aeruginosa) is a ubiquitous Organism that is often found in environment. It is a Gram-negative Bacillus, motile, straight (or) slightly curved measuring 0.5 – 8 Micrometer by 1.5 to 3.0 micrometer, non-spore forming, and Noncapsulated & obligate aerobes. Pseudomonas putida can appear Elongated. Organism from old culture may appear pleomorphic Gram Negative. Mucoid strains are seen as long filaments surrounded by Darker pink staining material (Alginate). Gram negative bacilli that are Showing intra cellular presence in polymorphonuclear leucocytes are Clinically important. Flagellar staining reveals single polar flagella. It Grows at wide temperature range between 6-42oc . Most pseudomonas species can reside in a wide variety of Environmental niches. Since their preferred temperature requirements Are between 4 and 36oc, Pseudomonas are found in processed foods, in Hands of health professional and they colonise animals and human. They Can spread among individuals. Ear infection and an irritating folliculitis may be acquired from Swimming pools, hot tubs. Community associated P. Aeruginosa Infections may occur as consequent to exposure to the organism in hot Tubs, whirlpools, and swimming pools. Keratitis due to P.aerugionsa May occur in individuals who store contact lenses in tap water and or Contaminated contact lens solutions. Intra venous drug users may Develop endocarditis and osteomyelitis as a result of injection of Contaminated injectables. P. Aeruginosa is also of nosocomial Significance The organism has been isolated from a variety of solutions Including soaps, ointments, irrigation and dialysis fluids, eye drops and Disinfectants as well as from fomites such as shower heads, respiratory Therapy unit, sinks, baths etc. Populations at risk for significant Morbidity and mortality include intubated patients in intensive care, Patients on chronic ambulatory peritoneal dialysis, and burns patients. Pseudomonas Species are associated with a number of Infections. They produce infections of wound and burns giving rise to Blue green pus. P. Aeruginosa can cause meningitis usually following Trauma (or) surgery. Corneal infections result from contaminated contact Lenses (or) injury, contaminated eye drops, and ointments. Pseudomonas Causes endocarditis through valve replacement. People who spend long periods for swimming are at risk for External ear infections (Swimmer’s ear). Malignant external otitis is a Virulent form of disease seen primarily in diabetes and elderly patients. P. Aeruginosa is the leading cause of chronic otitis media. Folliculltis is a common infection caused by Pseudomonas Species resulting from immersion in contaminated water (e.g. Hot tubs, Whirlpools, and swimming pools). Thermal burns of skin inhibit an Essential component of body defence against infection; the physical Barrier of intact skin .The resulting damaged tissue is a rich culture Medium and is a great risk for colonization and infection by Pseudomonas. Such infections have been the leading cause of morbidity And mortality. Infection of burn wound with Gram negative bacteria Typically occur one week after injury .The moist surface of the burnt Skin and lack of neutrophilic response to tissue invasion predispose Patients to such infections. Infections of the urinary tract are seen Primarily in patients with long-term indwelling catheter. The lungs of Children with cystic fibrosis are particularly susceptible to P. Aeruginosa. Use of ventilator which may introduce the organism to lower airways Produces lung abscess and pneumonia .The mortality rate is 70%. Epidemiological investigations of P. Aeruginosa infection have different Typing methods as follows 1 Biotyping 2. Antiobiotic Sensitivity Typing 3. Serotyping 4. Bacteriophage typing 5. Bacteriocin Typing 6. Modified Diene’s mutual Inhibition Test 7. Random Amplified Polymorphic DNA Study The Bacteriophage and Bacteriocin typing are outdated because Cross-reactions are more common. The Diene’s mutual inhibition test has been used as an Epidemiological tool to characterize Pseudomonas aeruginosa like Proteus mirabilis. The test was simple to perform and cheap and may Have utility in initial screening of P.aeruginosa isolates in suspected Common source epidemic. Genomic finger printing methods are now regarded as the most Accurate methods for the typing of microorganisms for epidemiological Purposes. These methods include pulse field gel electrophoresis, Ribotyping, and Polymerase chain reaction based finger printing (RAPD – PCR). In the present study, P.aeruginosa was isolated from heterogenous Clinical samples from patients attending Govt Rajaji Hospital, Madurai And were subjected to various tests to identify strain similarity. Further They were screened for similar homology using phenotypic test, Diene’s Mutual Inhibition test, and genotypic test RAPD – PCR.

Friction stir processing (FSP) has evolved as a novel solid state technique to fabricate aluminium matrix composites (AMCs) in the recent years. FSP technique was applied to synthesis AA6082/TiC AMCs in order to analyze the effect of TiC particles, its volume fraction on the microstructure, mechanical and the sliding wear behaviour. A single pass FSP was carried out using a tool with 1200 rpm rotational speed, whose travel speed of 60 mm/min and an axial force of 10 kN to produce the composite. AMCs with five different volume fractions (0, 6, 12, 18 and 24 vol.%) were synthesized. The microstructure of the AA6082/TiC AMCs was studied using optical and scanning electron microscopy. The microhardness and ultimate tensile strength (UTS) were measured and the sliding wear behaviour was evaluated using a pin-on-disc apparatus. Thus the results revealed that the TiC particles significantly influenced the area of the composite, dispersion, grain size of matrix, microhardness, UTS and sliding wear behaviour of the AA6082/TiC AMCs. With this the effect of TiC particles on fracture surface and worn surface is also reported in this paper.

An attempt was made to synthesize Cu/B4C surface composite using friction stir processing (FSP) and to analyze the influence of tool rotational speed on microstructure and sliding wear behavior of the composite. The tool rotational speed was varied from 800 to 1200 r/min in step of 200 r/min. The traverse speed, axial force, groove width and tool pin profile were kept constant. Optical microscopy and scanning electron microscopy were used to study the microstructure of the fabricated surface composites. The sliding wear behavior was evaluated using a pin-on-disc apparatus. The results indicate that the tool rotational speed significantly influences the area of the surface composite and the distribution of B4C particles. Higher rotational speed exhibits homogenous distribution of B4C particles, while lower rotational speed causes poor distribution of B4C particles in the surface composite. The effects of tool rotational speed on the grain size, microhardness, wear rate, worn surface and wear debris were reported.

Bio-degradable metals and alloys have been suggested as revolutionary potential materials for bone-related treatment. Of these materials, the AZ91 magnesium alloy (AZ91 Mg alloy) emerges as an attractive candidate due to its non-toxicity and outstanding mechanical properties. Even though magnesium alloys are widely studied as orthopedic implants for bone replacement and bone regeneration, their undesirable rapid corrosion rate under physiological conditions has limited their actual clinical applications. Therefore, increasing the corrosion resistance of the AZ91 Mg alloy is one of the key issues to address for the development of bio-degradable implants. In this study, a cerium oxide (CeO2) coating is developed on the AZ91 Mg alloy by electrodeposition with a view of minimizing its corrosion rate during the bone healing period. Further, to improve the clinical application of AZ91 Mg alloy, manganese (Mn) and strontium (Sr) substituted hydroxyapatite (Mn, Sr-HAP) coatings were developed on the CeO2 coated AZ91 Mg alloy. Hence, this study reports on the development of a Mn, Sr-HAP/CeO2 dual coating on the AZ91 Mg alloy to make it a suitable alternative material for orthopedic implants.

Aluminum rich intermetallic particles are potential reinforcements for discontinuously reinforced aluminum matrix composites (DRAMCs). The objective of the present work is to produce AA6061/Al 3 Ti and AA6061/Al 3 Zr composites using in situ casting technique and applying friction stir processing (FSP) to enhance the distribution and morphology of Al 3 Ti and Al 3 Zr particles. AA6061/Al 3 Ti and AA6061/Al 3 Zr DRAMCs were produced by the in situ reaction of inorganic salts K 2 TiF 6 and K 2 ZrF 6 with molten aluminum. The microstructure was observed using optical and scanning electron microscopy. AA6061/Al 3 Ti DRAMC exhibited clusters of Al 3 Ti particles while the segregation of needle shape Al 3 Zr particles was observed in AA6061/Al 3 Zr DRAMC. The prepared composites were subjected to FSP. Significant changes in the distribution and morphology of Al 3 Ti and Al 3 Zr particles were observed after FSP. The changes in microhardness and sliding wear behavior of AA6061/Al 3 Ti and AA6061/Al 3 Zr DRAMCs before and after FSP is detailed in this paper.

The dry sliding wear behavior of AA6061 matrix composite reinforced with aluminium nitride particles (AlN) produced by stir casting process was investigated. A regression model was developed to predict the wear rate of the prepared composite. A four-factor, five-level central composite rotatable design matrix was used to minimize the number of experimental runs. The factors considered in this study were sliding velocity, sliding distance, normal load and mass fraction of AlN reinforcement in the matrix. The developed regression model was validated by statistical software SYSTAT 12 and statistical tools such as analysis of variance (ANOVA) and student's t test. It was found that the developed regression model could be effectively used to predict the wear rate at 95% confidence level. The influence of these factors on wear rate of AA6061/AlNp composite was analyzed using the developed regression model and predicted trends were discussed with the aid of worn surface morphologies. The regression model indicated that the wear rate of cast AA6061/AlNp composite decreased with an increase in the mass fraction of AlN and increased with an increase of the sliding velocity, sliding distance and normal load acting on the composite specimen.

Friction stir processing (FSP) is as a novel modifying technique to synthesize surface composites. An attempt has been made to synthesis AA6082/TiC surface composite using FSP and to analyze the effect of tool rotational speed on microstructure and microhardness of the same. The tool rotational speed was varied from 800 rpm to 1600 rpm in steps of 400 rpm. The traverse speed, axial force, groove width and tool pin profile were kept constant. Scanning electron microscopy was employed to study the microstructure of the fabricated surface composites. The results indicated that the tool rotational speed significantly influenced the area of the surface composite and distribution of TiC particles. Higher rotational speed provided homogenous distribution of TiC particles while lower rotational speed caused poor distribution of TiC particles in the surface composite. The effect of the tool rotational speed on microhardness is also reported in this paper.

Friction Stir Welding (FSW) as a joining technique with regard to low melting temperature materials such as aluminum alloys has already been established and implemented in the industry. But, with regard to high melting temperature metals and alloys the major issue still to get successfully addressed is a pertinent tool material for a class of work materials and to get their operating parameters optimized. This paper presents a detailed assessment on the FSW of high melting temperature (HMT) materials, giving emphasis on the tool materials, tool geometry and FSW equipment aspects based on the information gathered from experimental studies and research publications.

Aluminium Matrix Composites (AMCs) reinforced with particulate form of reinforcement has replaced monolithic alloys in many engineering industries due to its superior mechanical properties and tailorable thermal and electrical properties. As aluminium nitride (AlN) has high specific strength, high thermal conductivity, high electrical resistivity, low dielectric constant, low coefficient of thermal expansion and good compatibility with aluminium alloy, Al/AlN composite is extensively used in electronic packaging industries. Joining of AMCs is unavoidable in many engineering applications. Friction Stir Welding (FSW) is one of the most suitable welding process to weld the AMCs reinforced with particulate form of ceramics without deteriorating its superior mechanical properties. An attempt has been made to develop regression models to predict the Ultimate Tensile Strength (UTS) and Percent Elongation (PE) of the friction stir welded AA6061 matrix composite reinforced with aluminium nitride particles (AlN p ) by correlating the significant parameters such as tool rotational speed, welding speed, axial force and percentage of AlN p reinforcement in the AA6061 matrix. Statistical software SYSTAT 12 and statistical tools such as analysis of variance (ANOVA) and student’s t test, have been used to validate the developed models. It was observed from the investigation that these factors independently influenced the UTS and PE of the friction stir welded composite joints. The developed regression models were optimized to maximize UTS of friction stir welded AA6061/AlN p composite joints.

Friction stir processing has evolved as a novel method to fabricate surface metal matrix composites. The feasibility to make B4C particulate reinforced copper surface matrix composite is detailed in this paper. The B4C powders were compacted into a groove of width 0.5 mm and depth 5 mm on a 9.5 mm thick copper plate. A tool made of high carbon high chromium steel; oil hardened to 63 HRC, having cylindrical profile was used in this study. A single pass friction stir processing was carried out using a tool rotational speed of 1500 rpm, processing speed of 40 mm/min and axial force of 10 kN. A defect free interface between the matrix and the composite layer was achieved. The optical and scanning electron micrographs revealed a homogeneous distribution of B4C particles which were well bonded with the matrix. The hardness of the friction stir processed zone increased by 26% higher to that of the matrix material.

Friction stir processing (FSP) has evolved as a novel solid state method to prepare surface composites. In this work, FSP technique has been successfully applied to prepare copper surface composites reinforced with variety of ceramic particles such as SiC, TiC, B4C, WC and Al2O3. Empirical relationships are developed to predict the effect of FSP parameters on the properties of copper surface composites such as the area of the surface composite, microhardness and wear rate. A central composite rotatable design consisting of four factors and five levels is used to minimize the number of experiments. The factors considered are tool rotational speed, traverse speed, groove width and type of ceramic particle. The effect of those factors on the properties of copper surface composites is analyzed using the developed empirical relationships and explained in this paper taking into account the microstructural characterization of the prepared copper surface composites. B4C reinforced composites have higher microhardness and lower wear rate.

Development of welding procedures to join aluminum matrix composite (AMCs) holds the key to replace conventional aluminum alloys in many applications. In this research work, AA6061/B4C AMC was produced using stir casting route with the aid of K2TiF6 flux. Plates of 6 mm thickness were prepared from the castings and successfully butt joined using friction stir welding (FSW). The FSW was carried out using a tool rotational speed of 1000 rpm, welding speed of 80 mm/min and axial force of 10 kN. A tool made of high carbon high chromium steel with square pin profile was used. The microstructure of the welded joint was characterized using optical and scanning electron microscopy. The welded joint showed the presence of four zones typically observed in FSW of aluminum alloys. The weld zone showed fine grains and homogeneous distribution of B4C particles. A joint efficiency of 93.4% was realized under the experimental conditions. But, FSW reduced the ductility of the composite.

The microstructure and mechanical characterization of dissimilar friction stir welded AA5083-H111 and AA6351-T6 aluminum alloys were studied. Three different welding speeds (36, 63 and 90 mm/min) were used to weld the dissimilar alloys. The effect of welding speed on mechanical and metallurgical properties was analyzed. It is found that the welding speed of 63 mm/min produces better mechanical and metallurgical properties than other welding speeds. The weld zone is composed of three kinds of microstructures, namely unmixed region, mechanically mixed region and mixed flow region. The fracture mode was observed to be a ductile fibrous fracture.

The objective of this work is to fabricate aluminium alloy AA6061 reinforced with ZrB2 particles (10 wt-%) by the in situ reaction of K2ZrF6 and KBF4 salts with molten aluminium. The microstructure, tensile strength, wear resistance and corrosion rate of the fabricated composite were compared with those of matrix alloy. The in situ formed ZrB2 particles were uniformly dispersed in the aluminium matrix predominantly concentrated in inter granular regions and refined the microstructure of the matrix alloy. The incorporation of in situ formed ZrB2 particles into the aluminium matrix improved tensile strength and wear resistance but reduced ductility and corrosion resistance.

Friction stir processing (FSP) was applied to fabricate boron carbide (B4C) particulate reinforced copper surface composites. The effect of FSP parameters such as tool rotational speed, processing speed and groove width on microstructure and microhardness was investigated. A groove was contrived on the 6 mm thick copper plates and packed with B4C particles. FSP was carried out using five various tool rotational speeds, processing speeds and groove widths. Optical and scanning electron microscopies were employed to study the microstructure of the fabricated surface composites. The results indicated that the selected FSP parameters significantly influenced the area of surface composite, distribution of B4C particles and microhardness of the surface composites. Higher tool rotational speed and lower processing speed produced an excellent distribution of B4C particles and higher area of surface composite due to higher frictional heat, increased stirring and material tranportation. The B4C particles were bonded well to the copper matrix and refined the grains of copper due to the pinning effect of B4C particles. B4C particles retained the original size and morphology because of its small size and minimum sharp corners in the morphology.

Aluminium alloys generally present low weldability by traditional fusion welding process. Development of the friction stir welding (FSW) has provided an alternative improved way of producing aluminium joints in a faster and reliable manner. The quality of a weld joint is stalwartly influenced by process parameter used during welding. An approach to develop a mathematical model was studied for predicting and optimizing the process parameters of dissimilar aluminum alloy (AA6351 T6-AA5083 H111) joints by incorporating the FSW process parameters such as tool pin profile, tool rotational speed welding speed and axial force. The effects of the FSW process parameters on the ultimate tensile strength (UTS) of friction welded dissimilar joints were discussed. Optimization was carried out to maximize the UTS using response surface methodology (RSM) and the identified optimum FSW welding parameters were reported.

Multi-criteria integrated production–distribution problems were solved by many researchers using different optimization techniques. A novel analytic hierarchy process (AHP) based heuristic discrete particle swarm optimization (DPSO) algorithm is proposed in this research for solving difficult production–distribution problems. A bearing manufacturing industry's case is considered in this paper and the mathematical model is formulated as mixed integer linear programming (MILP) problem considering multi-period, multi-product and multi-plant scenarios. The three major objectives considered are total cost reduction, minimization of change in labor levels and percentage under-utilization. The results of the AHP based heuristic DPSO algorithm are compared with the branch and bound algorithm results generated using LINGO software. The approach gives good near optimal solutions. In addition to the bearing manufacturing industry dataset, two other test datasets are also solved.

Over the last two decades, aluminium matrix composites (AMCs) reinforced with particulate form of ceramics have attracted much attention due to their superior mechanical properties. In recent years, friction stir welding (FSW) is largely employed to successfully join the AMCs reinforced with ceramic particulates. An attempt has been made to develop a regression model to predict the ultimate tensile strength (UTS) of the friction stir (FS) welded AA6061 matrix composite reinforced with aluminium nitride particles (AlNp) by incorporating significant parameters such as tool rotational speed, welding speed, axial force and percentage of AlNp reinforcement in the matrix. A four factor, five level central composite rotatable design has been used to minimize the number of experimental runs. The effects of those factors on UTS of the welded joints have been analyzed using the developed regression model. The developed regression model has been validated by statistical software SYSTAT 12 and statistical tools such as analysis of variance (ANOVA) and student’s t test. It was found that the model was accurate. The developed regression model can be effectively used to predict the UTS of FS welded joints at 95% confidence level. It was observed from the investigation that factors considered in this study independently influenced the UTS of the FS welded composite joints.

Friction stir processing has evolved as a novel solid state technique to fabricate surface composites. The objective of this work is to apply the friction stir processing technique to fabricate boron carbide particulate reinforced copper surface composites and investigate the effect of B4C particles and its volume fraction on microstructure and sliding wear behavior of the same. A groove was prepared on 6 mm thick copper plates and packed with B4C particles. The dimensions of the groove was varied to result in five different volume fractions of B4C particles (0, 6, 12, 18 and 24 vol.%). A single pass friction stir processing was done using a tool rotational speed of 1000 rpm, travel speed of 40 mm/min and an axial force of 10 kN. Metallurgical characterization of the Cu/B4C surface composites was carried out using optical microscope and scanning electron microscope. The sliding wear behavior was evaluated using a pin-on-disk apparatus. Results indicated that the B4C particles significantly influenced the area, dispersion, grain size, microhardness and sliding wear behavior of the Cu/B4C surface composites. When the volume fraction of B4C was increased, the wear mode changed from microcutting to abrasive wear and wear debris was found to be finer.

An aggregate production-distribution model, which minimizes the regular, overtime and outsourced production costs along with inventory holding, backorder, hiring/laying-off and trip-wise distribution costs, is developed for a renowned bearing manufacturing industry in India. The proposed integer non-linear programming INLP problem is NP-hard and hence a discrete particle swarm optimization DPSO algorithm is applied to solve the multi-site, multi-period production-distribution problem. The results obtained using DPSO algorithm are compared with the results of memetic algorithm MA, genetic algorithm GA and simulated annealing SA. DPSO algorithm results are far superior to that of other meta-heuristic approaches for the problem considered.

Friction stir processing (FSP) has evolved as a potential candidate to fabricate surface composites. This paper investigates the influence of traverse speed on microstructure and microhardness of Cu/B4C surface composite fabricated using FSP. The traverse speed was varied from 20 to 60 in steps of 20 mm/min. The tool rotational speed, axial force and groove width were kept constant. Optical microscopy and scanning electron microscopy were employed to study the microstructure of the fabricated surface composites. The results indicated that the traverse speed significantly influenced the area of the surface composite and distribution of B4C particles. The area of the surface composite was found to bear an inversely proportional relationship to traverse speed. Lower traverse speed exhibited homogenous distribution of B4C particles while higher traverse speed caused poor distribution of B4C particles in the surface composite.

Friction stir processing (FSP) is a novel solid state technique to refine the microstructure of metallic materials. The objective of this work is to apply FSP to change the morphology and distribution of intermetallic particles and achieve property enhancement. AA6061/8wt. % Al3Zr composite was produced by the in situ reaction of molten aluminum and inorganic salt K2ZrF6. Optical and scanning electron micrographs revealed a uniform distribution of needle shape Al3Zr particles in the aluminum matrix. The Al3Zr particles were located in the inter granular spaces. A double pass FSP was carried out using a tool rotational speed of 1200 rpm, processing speed of 50 mm/min and axial force of 8 kN. A tool made of HCHCr steel; oil hardened to 62 HRC, having a hexagonal profile was used. The needle shape Al3Zr particles were fragmented and converted into a spherical shape subsequent to FSP which resulted an increase in the hardness of the composite. Copyright © 2013 VBRI press.

Pitting is a form of extremely localized attack that results in holes in the metal. It is one of the most destructive and insidious forms of corrosion. It causes equipment to fail because of perforation with only a small percent weight loss of the entire structure. In this study, effects of plasma transferred arc welding parameters on the pitting corrosion resistance of Colmonoy 5 overlays deposited on austenitic stainless steel plates is investigated. Overlays were deposited as per designed experiments using response surface methodology. Potentiodynamic polarization technique was used for conducting the corrosion tests. A mathematical model for the pitting potential measured during the corrosion tests was developed using the multiple regression technique and it was used to correlate the effect of process parameters on the pitting potential of the overlays.

Objective : An experimental investigation was carried out to study the size effect on concrete specimens. Methods : In order to study the size effect compressive and split tensile test were conducted on standard and high strength concrete (M 30 and M 60 ) specimens of two different sizes of cubes (150 x 150 x 150 mm and 100 x 100 x 100 mm) and cylinders (150 x 300 mm and 100 x 200 mm) made of natural and artificial sand. In addition to this, the flexural strength test was also conducted for beam (500 x 100 x 100 mm) to compare the flexural strength of the beams made of natural and artificial sand. Findings: The result showed that the larger size concrete specimen fails at a lower stress than a smaller one and it was also observed that there was no significant variation in the strength with two sizes considered. The mechanical properties obtained with natural sand and artificial sand indicates that strength obtained for artificial sand was higher than that of natural sand for both M 30 and M 60 grade of concrete. Applications/Improvements: From this study, it was concluded that the standard cube of 150 x 150 x 150 mm and 100 x 100 x 100 mm can be used interchangeably for the test purpose. Similarly, for split tensile strength, standard cylinder of 150 x 300 mm and 100 x 200 mm can be used interchangeably.

Friction stir processing (FSP) has been developed by several researchers to produce an upper surface modification of metallic materials. The fabrication of TiC particulate (~2 $\upmu $ m) reinforced aluminum matrix composite (AMC) using FSP is studied in this paper. The measured content of TiC powders were compacted into a groove of 0.5 mm × 5.5 mm. A single pass FSP was carried out using a tool rotational speed of 1600 rpm, processing speed of 60 mm/min and axial force of 10 kN. A tool made of HCHCr steel, oil hardened to 62 HRC, having a cylindrical profile was used in this study. The microstructure and microhardness of the fabricated AMC were analysed. Scanning Electron Microscope (SEM) micrographs revealed a uniform distribution of TiC particles which were well-bonded to the matrix alloy. The hardness of the AMC increased by 45% higher than that of the matrix alloy.

The relatively new welding process friction stir welding (FSW) was applied in this research work to join 6 mm thick dissimilar aluminum alloys AA5083-H111 and AA6351-T6. The effect of tool rotational speed and pin profile on the microstructure and tensile strength of the joints were studied. Dissimilar joints were made using three different tool rotational speeds of 600 rpm, 950 rpm and 1300 rpm and five different tool pin profiles of straight square (SS), straight hexagon (SH), straight octagon (SO), tapered square (TS), and tapered octagon (TO). Three different regions namely unmixed region, mechanically mixed region and mixed flow region were observed in the weld zone. The tool rotational speed and pin profile considerably influenced the microstructure and tensile strength of the joints. The joint which was fabricated using tool rotational speed of 950 rpm and straight square pin profile yielded highest tensile strength of 273 MPa. The two process parameters affected the joint strength due to variations in material flow behavior, loss of cold work in the HAZ of AA5083 side, dissolution and over aging of precipitates of AA6351 side and formation of macroscopic defects in the weld zone.

Deciding the strategy for production and distribution in a stochastic demand scenario is important for the manufacturing industries. An integrated production-distribution plan considering regular, overtime and outsourced production costs along with inventory holding, backorder, hiring/laying-off and trip-wise distribution costs is developed for a renowned bearing manufacturing industry producing three types of products at three locations. Demand is assumed to vary uniformly and a novel simulation based heuristic discrete particle swarm optimization (DPSO) algorithm is used for obtaining the best production-distribution plan that serves as a trade-off between holding inventory and backordering products. The algorithm also uses an innovative regeneration type constraint handling method which does not require a penalty operator. In addition to the bearing manufacturing industry data set, two other test data sets are also solved. The simulation based optimization approach gives good approximate solutions for the stochastic demand problems.

An attempt has been made to manufacture aluminium (6061-T6) matrix composites reinforced with aluminium nitride particles (AlNp) of size 3–4 μ using indigenously developed modified stir casting method with bottom pouring arrangement in controlled argon environment. To improve the wettability of AlNp with molten Al matrix, 2% Mg has been added. AA6061–AlNp composites have been successfully produced at different weight percentages (viz 0, 5, 10, 15 and 20) of AlNp and their metallurgical and mechanical properties have been analysed. Macrohardness, microhardness, Yield strength and ultimate tensile strength of the composite have improved with the addition of AlNp in the Al matrix. Optical and SEM micrographs reveal the homogeneous distribution of reinforcement particles in the matrix and X-ray diffraction patterns ensure the dispersion of AlNp reinforcement in AA6061 matrix.

Friction stir processing (FSP) has evolved as a viable technology to fabricate surface composite layers. Hybrid composites have attracted the attention of researchers to minimize the wear of counterface materials. In this work, AA6360/(TiC + B4C) hybrid surface composite layers (SCLs) with various volume ratios of TiC and B4C were synthesized by FSP. The particles were compacted into a groove of width 0.5 mm, depth 5.5 mm and length 100 mm cut on the surface of the aluminum plate. The FSP was carried out at a tool rotational speed of 1600 rpm, traverse speed of 60 mm/min and axial force of 8 kN. Two passes were applied in opposite directions. The microstructure and sliding wear behavior of the fabricated SCLs were evaluated. TiC and B4C particles were distributed homogeneously in the SCLs. Both the particles behaved as one type of reinforcement particle during FSP. There was little or no comminution of ceramic particles. Addition of TiC and B4C particles enhanced the wear resistance of AA6360. 50%TiC + 50% B4C hybrid SCL exhibited lowest wear rate due to the formation of a thin tribo film. Detailed characterization of the worn surfaces and the wear debris was also reported.

Inadequate development of fabrication methods restricts the applications of new families of aluminum matrix composites (AMCs). Friction stir welding (FSW) is a potential candidate to join AMCs without any defects associated with conventional fusion welding processes. The primary objective of the present work is to apply FSW process to join AA6061/(0, 5 and 10 wt.%) ZrB 2 in situ cast composites and evaluate the joint properties. The composites were prepared by reacting inorganic salts K 2 ZrF 6 and KBF 4 with molten aluminum and joined using a FSW machine at a tool rotational speed of 1150 rpm, welding speed of 50 mm/min and axial force of 6 kN. The joints showed the presence of various zones such as weld zone (WZ), thermomechanically affected zone (TMAZ) and heat affected zone (HAZ). The weld zone was characterized with a homogenous distribution of ZrB 2 particles. The stirring action of the tool resulted in fragmentation of several clusters present in the parent composite. The weld zone exhibited higher hardness than that of the parent composite. The tensile strength of welded joints was comparable to that of parent composites. The wear resistance of the composites improved subsequent to FSW.

New families of aluminum matrix composites (AMCs) have been developed over the last decade in search of superior properties. Aluminum reinforced with ZrB2 particles is one such family which has drawn the attention of researchers. Friction stir welding is a relatively new solid state welding which overcomes most of the defects associated with fusion welding of AMCs. An attempt has been made to friction stir weld AA6061/0–10 wt% ZrB2 in situ composite and to develop an empirical relationship to predict the tensile strength of butt joints. Four factors, five levels central composite rotatable design was used to minimize the number of experiments. The factors considered are tool rotational speed, welding speed, axial force and weight percentage of ZrB2. The effect of these factors on tensile strength of the welded joints is analyzed using the developed empirical relationship. The predicted trends are discussed. It is observed that the factors independently influence the tensile strength over the entire range of parameters studied in this work.

The dry sliding wear behavior of AA6061/ZrB2 in-situ composite prepared by the reaction of inorganic salts K2ZrF6 and KBF4 with molten aluminum was investigated. An attempt was made to develop a mathematical model to predict the wear rate of AA6061/(0–10%) ZrB2 in-situ composites. Four-factor, five-level central composite rotatable design was used to minimize the number of experiments. The factors considered are sliding velocity, sliding distance, normal load and mass fraction of ZrB2 particles. The effect of these factors on the wear rate of the fabricated composite was analyzed and the predicted trends were discussed by observing the wear surface morphologies. The in-situ formed ZrB2 particles enhance the wear performance of the composite. The wear rate of the composite bears a proportional relationship with the sliding velocity, sliding distance and normal load.

PurposeThe SiC reinforced Al composite is perhaps the most successful class of metal matrix composites (MMCs) produced to date. They have found widespread application for aerospace, energy, and military purposes, as well as in other industries – for example, they have been used in electronic packaging, aerospace structures, aircraft and internal combustion engine components, and a variety of recreational products. In all these applications, welding plays a vital role. Little attention has been paid to SiC reinforced aluminium matrix composites joined by gas tungsten arc (GTA) welding. The purpose of this paper is to outline the manufacturing method for producing MMCs, GTA welding of MMCs and pitting corrosion analysis of welded MMCs.Design/methodology/approachThis paper focuses upon production and welding of metal matrix composites. The welded composites have been treated at elevated and cryogenic temperatures for experimental studies. Pitting corrosion analysis of welded plates was carried out as per Box Benkehn Design.FindingsFrom the results, it should be noted that maximum pitting resistance was observed with MMCs containing 10% SiC treated at cryogenic temperature. Corrosion resistance of welded composites treated at elevated temperature was found to be higher than that of as‐welded and at cryogenic temperature treated composites. The pitting potential increases with increase in % SiC to certain level and decreases with further increase in % SiC. Corrosion potential of composites treated at elevated temperature is high compared to other composites. Maximum pitting resistance is observed when the welding current was kept at 175 amps for 10% addition of SiC in LM25 matrix treated at cryogenic temperature.Originality/valueThe paper outlines the manufacturing method for producing MMCs, GTA welding of MMCs and pitting corrosion analysis of welded MMCs. The results obtained may be helpful for the automobile and aerospace industries.