Search

High precision and close tolerance is an essential requirement of current manufacturing industries dealing in micro-fabrication. The quality of surface obtained after machining process exhibits the...

The properties of the alloys and metal matrix composites processed by friction stir processing are significantly affected by some fundamental parameters like; type of reinforcement, weight or volume % of reinforcement, number of passes, rotational speed, etc. The current study was done to explore the effect of these parameters on the mechanical properties of aluminium-based materials processed by friction stir processing. It was observed during the literature survey that the strength and hardness increased by 30%–40% after processing Al-based materials up to 3–4 friction stir processing passes. The wear rate decreased by 25%–30% after processing the Al-based materials up to 3–4 friction stir processing passes. The wear rate gets reduced on increasing the value of rotational speed (about 60%–70% reduction in wear rate after processing the aluminium based materials at a rotational speed 1300 rpm–1500 rpm). As the grain size increases on increasing the tool rotational speed, strength and hardness decreases. On increasing the transverse speed, there is a reduction in the grain size. Hence, the strength and hardness increase with an increase in the transverse speed.

In this study, a re-investigation on metal matrix composite fabricated by powder metallurgy route has been done. Copper based metal matrix composite has the wide applications because of their good electrical, thermal and mechanical properties. Copper has good strength and resistance to corrosion. But in order to increase the properties of copper, copper matrix composite has been fabricated by powder metallurgy process. The composites materials fabricate by powder metallurgy process has various property such as hardness, tensile strength, compressive strength, toughness, fatigue strength. These properties depend on some parameter such as reinforcement, pressure during powder compaction, temperature of sintering, holding time at sintering temperature, particle size, volume fraction of reinforcement etc. This study shows investigation of effect of various parameter on mechanical property of copper-based metal matrix composites. It has shown that due to presence of secondary phase hard particle like alumina, SiC, titanium carbide, TiO2 in copper metal matrix increase hardness, strength and reduce density. Reduction in density is very important in order to fabrication of automobile and aircraft parts. The strength and hardness increase with addition of SiC but ductility is reduced. It is shown that sintering temperature and sintering time is most important parameter because it highly influences hardness and strength.

Welding and riveting are the two fundamental joining processes for metals. Welding joints have high strength than the riveting joints. But there is a high heat-affected zone in welding. The heat-affected zone is the reason for the stress concentration and pre-mature failure. The heat-affected zone and other properties (i.e., microstructural, mechanical, and corrosion) of a welded joint depends on the welding parameters. In the present work, a re-analysis of the effect of welding parameters is done on the microstructural, mechanical, and corrosion properties of the inert tungsten gas welded materials. It was observed that the grain coarsening occurred in the heat-affected zone, while in the fusion zone, grain refinement took place. Hence, the coarsening of grains reduced the hardness and tensile strength of the material in the heat-affected zone. Heat affected zone can be reduced by reducing the current, but the reduction of current reduces the penetration.

Equal-channel angular pressing (ECAP) is one of the emerging Severe plastic deformation (SDP) technique that makes ultra-fine grains (UFG) microstructure to improve the properties of different materials and composites. The uniqueness of the ECAP technique is that it can refine the grain size without changing the cross-section. Many factors like processing temperature, number of ECAP passes, die channel angle and processing route affects the results obtained from ECAP technique. This review is mainly focused on the mechanical and microstructural properties of aluminium alloys generated after ECAP Process along with number of passes. It is observed as the number of passes increased the hardness and tensile strength of the alloy increase and ductility of the material is reduced. The maximum percentage of grain refining is obtained in the first two or three passes after that no significant changes were observed because the effect of temperature is more than the effect number of passes on the grain size.

In cement industry, the production of cement leads to the formation of CO2 gas that subsequently disposed into the environment. To reduce or eliminate the production of CO2, cement is replaced with the industrial waste product to develop concrete. Therefore, various samples are prepared by replacing the cement with various industrial waste materials such as brick dust, marble dust, and ceramic dust in different proportion of 5%, 7.5%, 10%, 12.5%, 15%, 20%.Tests are conducted to know the mechanical properties of this concrete having MDP (marble dust powder), BDP (brick dust powder) and CDP (ceramic dust powder as replacement to cement. Compressive strength and split tensile strength testing of samples were conducted after curing the specimens for a set duration of 7 days, 28 days and 56 days. Additionally, slump test was done to predict the workability of concrete. In relation to MDP and BDP values of slump for CDP were found to be in decreasing order with increase in the replacement percentage. 10%, 12.5% and 7.5% were the best replacement percentages for MDP, BDP and CDP respectively in case of compressive strength test as well as split-tensile-strength for all days of curing. But CDP could not show the long term effect in strength increment in comparison with the conventional concrete.

Equal-channel angular pressing (ECAP) is also known as Equal-channel angular extrusion (ECAE) process. ECAP is a Severe plastic deformation process which can produce ultrafine grains with superior mechanical properties. There is a very significant role of number of passes in the ECAP process, mechanical properties and grain refining is depending on it. This study is focused on the influence of the number of passes and processing routes on hardness, tensile strength and elongation of different alloys, so only mechanical properties are mentioned under this review. Among all the processing route of the ECAP process, BC route shows the maximum strength. Some limitations or disadvantages related to the ECAP process are also discussed in this study.

In recent past a steep rise in research and development in manufacturing sector related to medical industry has been noticed. Extensive research has been undertaken for the establishment of novel approaches and techniques for evolving existing medical devices. In this article, a comprehensive review of biomedical implants and their relevance in day to day life in modern society is discussed. Currently, orthopaedic and dental implants market size is more than 4.5 billion dollars as per the global implant market size. The most common health problem found is osteoporosis, arthritis, accidental damage to bone etc. due to ageing issue, sudden rapture in the bone etc. to overcome such problems implants are recommended for improving the quality of life and performance of the defected organ or limb. The paper is organised as follows, a brief introduction of implants, history of implants, material, their properties and techniques used for fabrication of the medical implants.

In the present work, effect of strain rate on the simulation of forging deformation of Inconel alloy 751 steel has been done. Finite Element Analysis and Modeling carried out on the Deform™-3D software. The deformation simulation was done on the various strain rates of 1.9 s−1, 2 s−1 and 3 s−1 at the higher temperature of 1050 °C. The simulation is carried out at 10 mm/sec upper die speed considering the Coefficient of friction as 0.3 N. Distribution of temperature, load, stress and strain obtained from different strain rates are shown and discussed. The stress and strain distribution displayed diverse dissemination, signifying inhomogeneity throughout hot forging. As the strain rate increases the inhomogeneity in the deformation behaviour is reduced.

Aluminium matrix composites are the special class materials used in automobile, aerospace, nuclear, and packing industries. High demand for these materials is due to high electrical conductivity, high thermal conductivity, high strength, high wear resistance, high ductility, and excellent machinability. Stir casting, friction stir processing, and powder metallurgy are common techniques used for the fabrication of Aluminium matrix composites. Some of the advantages of the powder metallurgy technique such as, high material utilization, less power consumption, and less scrap, etc.; are the main reasons for the inclination of researchers towards the use of this technique for the fabrication of Aluminium matrix composites. The Powder metallurgy process parameters, i.e., compaction pressure, sintering temperature, and sintering time, highly influence the physical and mechanical properties of Aluminium matrix composites fabricated by powder metallurgy. The type and weight fraction of reinforcement also have a significant effect on the physical and mechanical properties of Aluminium matrix composites. In the present study, re-investigation has been done on the effect of the above parameters on the physical and mechanical properties of Aluminium matrix composites. During the literature survey, it was observed that, compaction pressure is the most influencing parameter. The Density and porosity can be controlled effectively by controlling the compaction pressure. For Aluminium-based materials fabricated by powder metallurgy, the optimum range of compaction pressure, sintering temperature, and sintering time is 600–700 MPa, 520–600 °C, and 3–4 h, respectively.

Now a days, tissue engineering plays an important role in replacement of damaged tissues and organs made using conventional method of manufacturing i.e., rapid prototyping. In this article, we discussed about effect of porosity and pore size of scaffold in tissue engineering with various fabrication techniques. Scaffolds are made porous to facilitate nutrients, oxygen diffusion and waste materials. This review paper also highlights the effect on mechanical properties due to porosity and pore size.

Present study discusses the processing and experimental investigation of hybridized nano-composites. The epoxy polymer reinforced by Al2O3 Polymer nanocomposites hybridized by Al2O3 of rod and spherical shape were prepared by in-situ polymerization technique. Spherical particle of 20–50 nm diameter and rod particles having 15–30 nm diameter & 50 nm length were used as nanofiller. The weight percent of nanofiller of 0.5 wt%, 1 wt% & 1.5 wt% were used for reinforcement of epoxy matrix. The tensile strength, elastic modulus was observed at different wt % nanofilled epoxy resin and the results were compared with the performance of neat epoxy samples. The reinforcement of nanofillers significantly affects the tensile strength and moderately affects the elastic modulus of polymer resin. The results reported that the tensile strength was improved from 58.7 MPa to 64.1 MPa. The microstructure of fractures specimen were observed by scanning electron microscope (SEM) to verify the strengthening mechanism.

Concrete is the most dynamic engineering material in construction industry because of its strength properties as well as its durability. The consumption of raw materials not only depleted natural resources but also increases the toxic material in the environment by the construction industries. The substitute products have been found to save the environment and natural resources up to some extent. In the same context, some usual composition of concrete mix is replaced by industrial/ natural wastes such as Fly Ash, Sugarcane bagasse ash and Banana fibre. The samples were prepared with the different composition using different % replacement of cement and sand. Therefore, concrete mix is developed using fly ash (replacing 20% of cement) and partial replacing sand by an industrial waste i.e. Sugarcane bagasse ash (replacing 0%,10%,20% of sand) with adding banana fiber (0%,2.5%,5%). Samples were evaluated and compared with standard concrete mix under characteristic compressive strength and flexural strength. It was observed that observed that addition of 2.5% of banana fibre in Cement; partially replaced by 20% of Fly Ash, and Sand; partially replaced by 10% of Bagasse Ash is the best Combination which gives better mechanical properties.

In the present work, a composite material is developed using stone dust and ceramic waste. The stone dust and ceramic waste are the replacements of natural sand and stone respectively. The developed composite is tested for various mechanical testing to know the strength under compression, flexural and shear. Seven different types of samples were casted by varying the stone dust from 0% to 100% in the interval of 20%. The ceramic waste aggregate was kept constant at 20% in all the samples except in conventional concrete sample. The workability of the mix was improved by adding PCE based superplasticizer. The results showed that the replacement of stone aggregates with ceramic waste alone tends to reduce the mechanical strength of the concrete. As compared to conventional concrete, compressive and flexural strength of the S0C20 sample (i.e. 0% stone dust and 20% ceramic) is slightly reduced. The maximum strength, was obtained in S40C20 sample (i.e. 40% stone dust and 20% ceramic) for compression, shear as well as in flexure. Therefore, the natural sand and stone aggregates can be partially replaced with stone dust and waste ceramic aggregates respectively for the manufacturing of a composite material (i.e. concrete) in an optimized percentage.

In the present work, a geopolymer concrete composite is developed using GGBS, Fly ash and superplasticizer. Two types of samples are prepared with increasing dosage of superplasticizer (i.e. 1%, 2% and 3%). In the first case, only ground granulated blast furnace slag is used and in the second case, 50% GGBS with 50% Fly ash is used. The developed geopolymer composite is tested for its mechanical and durability properties. Compressive strengths and split tensile strengths are determined to assess the mechanical properties and water absorption test is done for testing the durability of the composite. The results showed that, the maximum improvement in mechanical and durability properties are obtained with 3% superplasticizer dosage. The maximum compressive strength of 40.2 MPa and maximum split tensile strength of 2.87 MPa is obtained for G100F0-3 sample. The water absorption for this mix is found to be 2.41%. Therefore, 3% dosage of superplasticizer can be used to develop geopolymer concrete composite in an optimized manner.

Metal forming process is one of the oldest manufacturing techniques. It has witnessed the shift from conventional to integration of smart systems for manufacturing of highly complex components. Many mathematical, experimental and simulation software techniques are discussed. Servo press is the most indispensable machine used for the manufacturing of delicate parts of automobile, aviation industry with high accuracy. The main motive of replacing or modifying the prevailing conventional manufacturing techniques into modern, smart and sustainable manufacturing like industry 4.0 is to become more competitive and to adopt customization & sustainability. Integration of industrial internet of things (IIoT) with automated supply chain has given optimized productivity, quality, and economical feasibility. This manuscript throws some light on different metal forming process, servo press application in automobile, aviation industry and different components require to make metal forming smart and sustainable in term of industry 4.0.

RMD™ welding has been developed for a variety of steels to regulate the rate of metal transfer effectively during the short-circuiting mode of the GMAW process. To achieve the desired weld quality,...

In this study, the microwave hybrid heating process has been exploited to produce optimized joints of SS304/SS316. Three input parameters: materials of the specimens to be joined (X), grain-size of...

Inconel 600 super alloy is chromium rich alloy having excellent oxidation and corrosion resistance at elevated temperatures. Due to these excellent properties, it is widely used in aerospace components such as blades, shafts and aircraft gas turbines. To know the high temperature deformation behaviour, Inconel 600 is hot deformed at elevated temperature ranging from 950 °C to 1100 °C with different strain rates range from 0.001 s−1 to 1 s−1. The true stress-true strain curves are plotted using the data obtained from hot compression. The true stress-true strain curves revealed that the deformation at lower strain rates showing softening for entire range of deformation temperature. Whereas, deformation at higher strain rate revealed strain hardening for entire range of deformation temperature. Softening could be due to dynamic recrystallization (DRX) or the instability in the deformed microstructure.

In the present review article, influence of S and Mn on microstructure and mechanical properties is studied. Additionally, effect of manganese and sulfur on the wear property of grey cast iron was also reviewed. The data from different experiments were taken under consideration and studied for the examination of the alloyed cast iron. The study describes that on increasing the manganese content of the grey cast iron, wear coefficient and hardness decreases and impact energy increases. The main motive of addition of manganese is to control the adverse effect of sulfur on the mechanical properties of grey cast iron. Moreover, the presence of manganese counter the formation of FeS, which is the reason for hot shortness in the alloy.

The effect of alloying element addition in grey cast iron is great interest of materials developers. In the same context, the effect of adding niobium on mechanical properties of grey cast iron is reviewed. Microstructure and hardness test are reviewed to examine the mechanical properties of alloyed grey cast iron. The study indicated that increasing niobium results in increasing hardness due to which wear rate reduces and also reduces the lamellar spacing between the graphite layers. The reduction in lamellar spacing is due to decreases in eutectic temperature with the addition of niobium. Additionally, mechanical properties including hardness and wear resistance were enhanced after adding niobium.

Magnesium and its alloys can also be used as a degradable implant as a ceramic material which is highly applicable in biomedical industries. As medical devices require a strong surface integrity of the parts as well as high geometric precision. Therefore, it is necessary to find the optimal surface parameters in order to minimize the risk of inflammatory reactions, reduce friction or increase cell adhesion for optimal fitting, mechanical stability, and biocompatibility. Hence, present work emphasized on the effect of input parameters such as distributor current (A), work on time (B), work off time (C) on surface roughness during the Electric Discharge Machining (EDM) of pure magnesium (Mg). In the present work, Taguchi and TLBO analysis are used to obtain the optimal parametric combination to achieve better surface quality.

For many years titanium-based biomedical devices are gaining a promising place in modern society. Titanium is one of the best suitable materials for manufacturing bio implants and its application areas are orthopedics, dentistry etc. There are many features possess by titanium which make it appropriate are its biocompatibility, resistance to corrosion, wearing, osteoporosis etc. The Cp- Titanium and titanium-based alloys are categorized in three ways depending upon its microstructure such as (α + β), α- type, β-type and comparative analysis are done its behavior, stability through SEM. This review paper discussed the conventional and modern methods of fabricating the bio-implants and also summarizes the various additive manufacturing techniques.

With the utilization of the weight reduction process and electrochemical measurements, we recognized that the extract of Terminalia chebula can go about as a corrosion inhibitor for low carbon steel using sulfuric acid as corrosive media. This extract shows great corrosion inhibition effectiveness at specific concentrations of the inhibitor. It is observed that the inhibition efficiency increases with increasing the inhibitor concentration and it decreases with increase in temperature. The surface morphology of steel has also studied by using scanning electron microscopy and atomic force microscopy. Further, the Langmuir adsorption isotherm was used to check the adsorption behavior, and we performed the DFT calculations to show the energy difference between the HOMO and LUMO.

Grey cast iron is used to make brake disc due to its high damping vibration resistance and low cost. In the present work, effect of silicon addition on microstructure and mechanical properties of grey cast iron is reviewed. Results of microstructure and mechanical properties are compiled, which are affected due to the addition of silicon in grey cast iron. From the review, it is found that the volume of soft graphite flakes increases i.e. grain size increases which reduces the hardness of grey cast iron, on increasing the silicon content. Similarly, tensile strength reduces as a function of silicon addition. Hardness and wear rate depends on the phase of microstructure and the size of graphite flakes. Maximum hardness was obtained at 3.33% of silicon content.

Powder bed fusion process is one of the basic technique associated with additive manufacturing. It follows the basic principle of manufacturing the product layer by layer and their fusion. A heat source focuses its heat over a powder base material and heats the selected cross section area. Sources like laser beam, electron beam and infrared beam are used as heating tool. The process of heating allows the powder to take the shape of the intended object. Powder bed fusion process is compatible to every engineering material such as metals, ceramics polymers, composites etc. this technique is widely used in many industrial sectors such as aerospace, energy sector, transportation etc. A comprehensive overview on powder bed fusion process is presented in this review paper. Other popular techniques like selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting (EBM) are also reviewed.

In the present study, a reanalysis of Magnesium based metal matrix composites made by powder metallurgy has been done. The Properties of the powder metallurgy products are highly influenced by some basic parameters like; type of reinforcement, weight or volume fraction of reinforcement, compaction pressure, sintering temperature and sintering time, etc. That is why the present study was focused to investigate the effect of these parameters on the mechanical properties of magnesium based Metal Matrix Composites (MMCs). It was observed that the hard ceramic particles like Al2O3, SiC, B4C, TiO2, TiC and etc. are reinforced in the magnesium matrix to enhance the strength, hardness and other properties. The strength and hardness increases on addition of these hard ceramic particles but ductility is reduced. It has been also observed that the metallic reinforcement like Titanium increases both the strength as well as the ductility of Magnesium based MMCs.

In these decades, there has been an increasing demand for magnetic field-assisted surface finishing processes in the industries. It is due to specific features available in the magnetic assisted surface finishing process; these are contactless and effectively controlling of magnetic forces in the intricate passage. These processes are hybridized by modification in the existing conventional surface finishing process or by clubbing two or more unconventional surface finishing processes. Magnetic Abrasive Flow Finishing (abbreviated as MAFF) process is an unconventional process used for internal cylindrical surface finishing, intricate and complex inside profile geometry. It is a hybrid process that gives a combined effect of AFM and the MAF process. MAFF was developed by the researchers Sahijpal Singh and H.S. Shan in the 2000s. They modified the AFM by applied an electromagnet around the workpiece. The main drawbacks of AFM’s process were low material removal rate and time-consuming process. MAFF was an advancement of AFM, in MAFF process material removal and surface finishing both considerable optimize. MAFF has a broader range of applications in electronics manufacturing of aerospace, semiconductor, automotive components, and medical components like biopsy needle.

A powered ankle foot orthotic (AFO) device has been designed not only for patients having foot drop problem but also improve the movement of ankle joint for patients with lower limb disabilities. Different materials like poly lactic acid (PLA), polypropylene and ABS are been used to be designed and analyzed with computer aided design (CAD) and Finite Element Analysis software and which help to select the best material for fabrication purpose. This research article presents an externally powered portable ankle foot orthosis fitted with microcontroller, stepper motor to provide dorsiflexion and plantar flexion assistance during patients walking suffering from foot drop. At first the 3D model has been analyzed which designed in CAD module with selected material using analysis software and then mechanical structured AFO has been developed on the basis of GAIT parameters accordingly the AFO is assembled. The aim of this paper is to design, manufacture and delivering customized AFO that is patient specific.

The addition of any alloying element alters the various properties of developed alloy, wherein mechanical properties influence significantly. The present work reviews the effect of molybdenum (Mo) and copper (Cu) addition in grey cast iron. It alters the few mechanical properties such as tensile strength, hardness and toughness of grey cast iron and are covered in this review article. It is reported that on increasing the percentage of copper and molybdenum in grey cast iron, tensile strength and hardness increases and impact energy decreases. But, beyond a certain amount of copper and molybdenum addition, there is a negligible effect on the hardness. Thus the main role of copper and molybdenum addition, is to reduce the volume of graphite flakes and increase the content of pearlite in microstructure of gray cast iron.

The present review paper complies the information of Ti and its alloys from basic processing to mechanical properties, along with various microstructure and heat-treatment processes. The basic processing routes and reaction to develop pure titanium from ore is explained. The role of stabilizers on pure titanium and their classifications as α-phase or β-phase stabilizers are explained with the details of respective elements. The various kinds of microstructure available in Ti or its alloys are shown and explained. The microstructure of alloy can be altered with help of processing conditions, composition and/ or cooling rate and medium. The resulted microstructure obtained after heat treatment of various Titanium alloy are lamellar, bimodal, equiaxed, basket-weave, acicular and widmanstatten, which exhibits different mechanical properties. Generally, Titanium alloy with fully lamellar structure shows higher fracture toughness and crack resistance while equiaxed structure shows high cycle fatigue resistance. Cooling rate and cooling medium also results in different microstructure. It was observed that water cooled titanium alloys shows highest hardness due to martensite formation because of rapid cooling followed by air and furnace cooling.

Solution heat treatment and Cryogenic treatment of Al6082 aluminium alloy were experimentally carried out at Temperature 520 °C and −183 °C temperature by using muffle furnace and by dipping the specimen in liquid nitrogen solution bath respectively. The soaking time is varied from 10 min to 24 h in four step (10 min, 30 min, 60 min and 24 h). The variation in the tensile strength and hardness were evaluated. The tensile strength and hardness increases as a function of cryogenic duration. The results were compared with as received and solution treated specimen. The microstructure of the solution and cryo-treated specimen were studied by optical microscope. The grain size refinement was recorded in cryo-treated specimen. The grain size refinement increases with increase in the duration of cryo-treatment. The fractography of broken tensile specimen were done using SEM to discuss about ductile and brittle fracture.

For the first time, an equiatomic refractory high entropy alloy (RHEA) TiNbZrHfTa compact with a single-phase body-centered cubic (BCC) structure was fabricated via a titanium hydride (TiH2) assisted powder metallurgy approach. The constituent pure Ti, Zr, Nb, Hf, and Ta powders were mechanically alloyed (MA) with titanium hydride (TiH2) powder. The resultant MA powder was dehydrogenated at 1073 K for 3.6 ks and subsequently sintered through spark plasma sintering (SPS). Additionally, TiNbZrHfTa counterparts were prepared from pure elements without MA with TiH2. It was observed that the compact prepared from pure powders had a chemically heterogeneous microstructure with hexagonal close packed (HCP) and dual BCC phases. On the other hand, despite containing many constituents, the compact fabricated at 1473 K for 3.6 ks via the hydride approach had a single-phase BCC structure. The Vickers microhardness of the TiNbZrHfTa alloy prepared via the hydride process was Hv 520 (&plusmn, 30). The exceptional microhardness of the alloy is greater than any individual constituent, suggesting the operation of a simple solid-solution-like strengthening mechanism and/or precipitation hardening. In addition, the heat treatments were also carried out to analyze the phase stability of TiNbZrHfTa prepared via the hydride process. The results highlight the substantial changes in the phase as a function of temperature and/or time.

The mechanical behaviour of orange peel reinforced with epoxy composites is investigated by increasing the percentage of the orange peel reinforcement mechanical properties in the developed composite. Composite having 10%, 20% and 30% weight fraction of orange peel was made using hand layup method. Samples for different mechanical testing were prepared according to ASTM standards to check the hardness, tensile strength and density. Experiments were conducted on prepared samples and orange peel epoxy composite with the finding that 20% fibre percentage is optimum.

A numerical and experimental investigation of gas tungsten arc welding (GTAW) of AISI 304L was carried out to obtain the thermal field, depth of penetration with varying input process parameters. A three-dimensional finite element model is developed to simulate the GTAW welding process considering double ellipsoidal heat source with Gaussian heat flux distribution. A novel iso-volume approach is used to estimate the melting efficiency of the process and calculated maximum melting efficiency of the process is found 44 %. Calculated results in terms of thermal histories and depth of penetration have compared with measured results and are in good agreement.

The present work aims to review the welding behavior of welded AISI duplex stainless steel 2205(DSS). DSS has duel phase structure i.e. austenite and ferrite phases and therefore, combines the properties of both the phases. DSS is commonly used as high corrosion and pitting resistant material in aggressive environments. Welding process involves electrical, thermal, chemical, fluid and mechanical phenomenon. It also involves the melting of the faying surfaces of the DSS and subsequent solidification. These melting involves heating of base metal near to fusion zone which is coined as heat affected zone (HAZ). These region depends on the heat input, thermal field, melting of filler, the rate of cooling, process variables and technique used. The effect of different parameter of welding involved in various welding processes used for DSS welding such as gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), submerged arc welding (SAW), plasma arc welding (PAW), Friction stir welding (FSW), laser and electron beam welding (LBW/EBW) are reviewed. Additionally, a compressive study is done on the effect of welding on corrosion, mechanical properties and subsequently on the microstructure of DSS.

Low carbon steels of varying vanadium nitrogen ratio are hot rolled at 800°C with varying percentage of deformation within 20% to 60% thickness reduction. A set of experimental steels are subjected to hot compression using Thermo-Mechanical Simulator (Gleeble3800®) and then cooled to room temperature. Microstructural characterization was done using optical and scanning electron microscope. It is found that the increasing deformation percentage leads to the formation of higher amount of precipitates of vanadium carbides/carbonitrides. Additionally, precipitation density increases as a function of vanadium to nitrogen ratio. Higher amount of deformation in thermo mechanical simulation has led to higher hardness due to increase in precipitate density.

Zr-Nb alloys are usually processed in two phase region to get desired microstructure and mechanical properties for structural applications in nuclear industries. In the present work, small punch test (SPT) was performed to evaluate mechanical properties of the samples after hot compression in the two phase region at different temperatures and strain rates. The microstructure after hot deformation was characterized by the size of primary α, secondary α lath size, prior β grain size and texture developed. The deformed samples were characterized with the formation of 〈 11 2 ¯ 0 〉 fiber, which was found to strengthen with increase in deformation temperature. The yield load and maximum load was found maximum for sample deformed at 815 °C/1 s−1 due to combined effect of higher dislocation density and finer α lath size.

Zr-1Nb alloy is normally processed in two phase region to get desirable microstructure and properties for fuel cladding tube application in the nuclear reactor. Thus, it is important to know the deformation behavior of individual phases in the two phase region. However, the conventional approach to develop processing maps is to use flow stress data obtained from hot compression experiments, without accounting for the phases present at different temperatures. This approach fails to bring out the details about the operating deformation mechanism in the individual phases. In order to bring out these details, two new approaches are proposed for developing processing maps. The validity of the approaches is confirmed by performing microstructural analysis using electron backscattered diffraction (EBSD) studies. EBSD analysis of the microstructures obtained after deformation in the two phase region confirmed that α−phase had undergone dynamic recrystallization (DRX) whereas, β−phase exhibited coarse elongated grains. Processing maps developed using the new approaches were able to predict domains of high dissipation efficiency, which is corroborated by microstructural analysis. Also, one of the novel approaches proposed in this work could delineate the contribution of each phase in the two phase region.

In nuclear water reactors, zirconium alloys are extensively used as fuel cladding material and in other structural applications. Uniaxial hot compression tests were performed to understand the deformation behavior of Zr-1Nb alloy. Therefore, hot compression tests were performed in the temperature range of 700-1050°C, which envelopes α-phase, (α+β) phase, and β-phase. True stress-strain curves, processing maps, microstructural observation and kinetic analysis were used to discuss the deformation behavior of Zr-1Nb alloy. Deformation at a strain rate of 10-2 s-1 reveals softening at lower temperatures and steady state behavior at higher temperatures. Processing map also reveals domain of high efficiency at 10-2 s-1 strain rate for a wide range of deformation temperatures. The flow softening and high power dissipation efficiency predicts dynamic recrystallization or dynamic recovery during the hot deformation of studied alloy.

The chapter focuses on learning styles and how learning styles came about in education. There are many significant things to know about why educators should understand the learning style of a student. The learning method was one of the significant elements of human existence. Student learning styles are among the variables that have been obtained. The primary aim of this research was to explore the study of teaching style among learners with academic accomplishment in engineering. The research requires a theoretical approach to reviewing appropriate literature on the subject and presents different points of perspective on matching or mismatching learning styles. The conclusion of the chapter is how to learn the styles of teaching and learning impressively and effectively, and how an individual understands new information so that they can find the most efficient technique to accumulate, interpret, and present information.

Hot compression tests on TiHy 600 alloy (equivalent to IMI 834) is performed using Gleeble-3800® thermo-mechanical simulator. The hot deformation behavior of TiHy 600 alloy is characterized on the basis of flow stress variation with true stress-true strain curves at different strain rates ranging from 10−3 s−1 to 10 s−1 and hot deformation temperatures ranging from 900 °C to 1050 °C, with maximum engineering strain up to 50%. The flow stress is found to be strongly dependent on deformation temperature, strain rate and strain, and it decreases with increasing temperature and decreasing strain rate. The flow curves at various temperatures and strain rates also showed dynamic recrystallization process at temperature range (900 °C–975 °C) in all strain rates and dynamic recovery process at high temperature range (1000 °C and above) in all the strain rates. Using flow stress values from the true stress-true strain curves and by applying dynamic material modeling approach, processing maps are developed at various true strains of 0.3, 0.4, 0.5 and 0.6. Processing maps exhibited safe and unsafe domains with varying efficiency of power dissipation values. Safe and unsafe domains at 0.6 strain are derived from their flow curves are correlated with its related microstructures and misorientation distribution profiles. Hot compression at 900 °C (α-rich region) mostly resulted into new fine dynamic recrystallized equiaxed α grains along grain boundaries of large deformed α grains. Higher temperature (950 °C–975 °C) compression in the (α+β) region generated mixture of deformed large alpha grains containing subgrain boundaries and secondary α laths generates from deformed β. Further compression at higher temperature (1000 °C -β-rich region and 1050 °C -single β region) resulted in the formation of secondary α laths from deformed β with few equiaxed α grains at 1000 °C sample only. The misorientation profile of α phase corroborates with the deformation mechanism in α region through its equiaxed α grains and in β region through its secondary α variant laths misorientations.

Dominant phase during hot deformation in the two-phase region of Zr–2.5Nb–0.5Cu (ZNC) alloy was studied using activation energy calculation of individual phases. Thermo-mechanical compression tests were performed on a two-phase ZNC alloy in the temperature range of 700–925 °C and strain rate range of 10 −2 –10 s −1 . Flow stress data of the single phase were extrapolated in the two-phase range to calculate flow stress data of individual phases. Activation energies of individual phases were then calculated using calculated flow stress data in the two-phase range. Comparison of activation energies revealed that α phase is the dominant phase (deformation controlling phase) in the two-phase range. Constitutive equations were also developed on the basis of the deformation temperature range (or according to phases present) using a sine-hyperbolic type constitutive equation. The statistical analysis revealed that the constitutive equation developed for a particular phase showed good agreement with the experimental results in terms of correlation coefficient ( R ) and average absolute relative error (AARE).

TiHy 600 is a near alpha titanium alloy similar to IMI 834 Ti alloy, widely used for gas turbine engine applications such as disc and blades for high pressure compressors. Flow behavior of TiHy 600 alloy is investigated by conducting hot compression tests at temperatures ranging from 900°C to 1050°C with in the strain rate range of (0.001/s) respectively up to 50% deformation. Constitute modeling of work hardening is established, using Cingara equation to verify the stress up to peak stress. It was found that experimental true stress-true strain curves are in good agreement with Cingara equation curves for all temperatures at strain rate of (0.001/s)up to their peak stress values. The average activation energy (Q) is calculated from the peak stress of the flow curves using the hyperbolic-sine law equation (Arrhenius equation) i.e. 851.506KJ/mol. The microstructures of 50% deformed samples are correlated with the post-peak stress flow curve, performed mainly to compare the various softening processes (DRV or DRX).

Dynamic materials model (DMM), modified dynamic materials model (MDMM) and α-parameter were used to develop processing maps of Zr-2.5Nb alloy. Gleeble-3800® thermo-mechanical simulator was used to obtain flow stress at different temperatures and strain rates in the range of 700–925 °C and 0.01–10 s−1 respectively. Suitability of the three models in predicting the hot deformation behavior of Zr-2.5Nb alloy was evaluated by microstructural studies. DMM was found appropriate to delineate different deformation conditions for this alloy.