Manufacturing and Processing of Advanced Materials

In recent times, there has been an increasing demand for dissimilar metal fabrication, as this weldment utilizes the specific benefits of different metals for a particular application. In this paper, the recent trends evolving in the field of dissimilar material joining, which introduces residual stresses, distortions and formation of brittle intermetallics within the structure is discussed. As these are highly undesirable, therefore various techniques were studied by the researchers, which reduce the distortions and formation of brittle intermetallics. The use of numerical techniques in this field was also studied as they provided the researchers with an insight into the process. Mostly, the joining of dissimilar material is done using friction stir welding and laser welding, but the use of friction stir welding has constraints in terms of material temperature thus, the joining of dissimilar weldment is discussed by giving a special context to laser welding technology. 

Composite materials define the new age for the development of technologies. In a recent study of aerospace structure, conventional materials are replaced by almost 75% by modern composites. The strength-to-weight ratio of aluminum alloys makes it an attractive choice among other materials for industries. Carbon fiber-reinforced composite materials are better alternatives to conventional materials to prepare lighter panels. In many applications, the joining of these composites becomes troublesome. The promising technique to join the advanced composites is still unrevealed. The proper joining method is an essential need for composites. With this aim, we carry out the study to check the feasibilities of Friction Stir Welding for light panels used in aerospace industries. Friction Stir Welding is a solid-state welding method. The external tool solidifies and mixes the metal at the edge line. We reviewed several research articles to understand the difficulties associated with the friction stir welding method. 

Binder jetting (BJ) is a 3D printing technology in which objects are manufactured from ceramics, metals, polymers, and composites. Binder jetting process incorporates various types of technologies, such as printing, deposition of powder, complex combination of the binder with powder, and post-processing of sintered part. BJ has high productivity with the utilization of a wide variety of powders. In BJ, the binder is combined with powder of materials that bond together to create an object in a layer-wise fashion that is generally modeled on CAD. In order to obtain desired product accuracy, the main challenges are balancing proper process parameters with manufacturing time, such as characteristics of powders (distribution of particle size, packing density and flowability of powders, green strength), characteristic of binders, etc. This paper gives a brief review of technologies, materials, defects and challenges of the binder jetting additive manufacturing process and their future trends. 

Spot welding of dissimilar materials Al6061 and SS304 with an interfacial coating of Graphene Nano platelets (GNPs) by using the Resistance spot welding (RSW) technique is described in this chapter. A thin layer of GNPs (a few micrometers thick) is incorporated as an interlayer between Al6061/SS304 sheets (thickness 1 mm) and spot welded in lap configuration. RSW parameters play a vital role in this joining process. It was observed the strength of the lap joint increases with welding time and current. The method of welding held up the metal ejection, which occurs at high welding conditions. The influence of process parameters (welding current, time) on the mechanical and microstructural properties of the spot-welded joint was evaluated in detail. A tensile test was carried out in lap-shear mode to evaluate the strength of the joint and to determine the peak load. The fusion zone and the weld nugget were characterized by Scanning Electron microscopy and hardness analysis. SEM analysis observes that Fe and Al matrix well looped around the Graphene particles leads to the formation of inter-metallic compounds of Fe-GNP, Al- GNP, and Fe-Al-GNP at the joint interface. The results are compared with the properties of joints without and with GNP interlayer. It was found that the GNP interlayer enhances the properties of the spot-welded joint and increases joint strength. Possible strengthening mechanisms include enhanced grain refinement and dislocation pile-ups in the presence of the GNPs. 

Laser welding is a viable method of joining aluminium alloys. The input parameters employed in the welding process have a significant impact on the weld quality. There are several parameters that influence weld quality, however, describing their relationship with weld seam characteristics is challenging. This study uses the Taguchi approach and particle swarm optimization (PSO) techniques for improving the weld quality in an Al 2024 lap joint to achieve a consistent and reliable joint. The experiments are performed on a laser welding machine following an L9 orthogonal array experimental design with peak power, scanning speed, and frequency as input parameters. Here, breaking load, bond width and throat length are considered as the responses. Experimentally a maximum breaking load of 1233 N and a minimum bond width of 398.81 µm is achieved. The throat length ranged from 340.72 µm to 983.94 µm. Regression analysis is used to establish the relationship between the input and the responses. The regression equations are utilized as the objective function in an optimization problem. The crowding distance PSO is used to acquire the global optima. Finally, the optimal process parameters for achieving the desired goals are presented.

Electro-chemical discharge machining (ECDM) is a hybrid machining process that can machine conductive and non-conductive materials at the micro level. It caters to the benefits of two well-established constituent processes, namely, electrochemical machining (ECM) and electric discharge machining (EDM). The technology is quite established. However, the control of discharges in ECDM still needs further research. In this view, the present study reviews the various theories and mechanisms of discharge in ECDM given by researchers. The study also comprises an introduction to the ECDM technique, its various names given by different researchers, applications, and historical developments.

Electrochemical discharge machining (ECDM) process is an arising unconventional machining process for the micromachining of non-conducting materials. During the ECDM process, surface damages, machining continuity at higher depths and hole over cut (HOC) are the main issues during drilling. Previous researchers reported that gas film thickness, debris evacuation and electrolyte replenishment are the prime reasons for the lack of surface quality and lower hole depth. The present investigation has employed a magnetic field during the machining process, and they found a positive effect on the above-mentioned issues. Lorentz force was produced during the machining process, and created a circular motion of the electrolyte around the tool electrode. This phenomenon helped to control the gas film thickness, debris flushing, and electrolyte replenishment at the tool end. In the present work, the authors used a 1300 Gauss Fe-based ceramic permeant ring magnet. Magnetic field strength for both south and north poles was measured using a digital Gauss meter. A high-speed image-capturing camera was used to understand the bubble generation, gas film formation, and debris evacuation during the machining process. The authors applied both north and south-pole magnetic fields for the investigation of the machining process and compared the results with the conventional ECDM process. Better results in surface quality, hole depth, and HOC were achieved with the south pole magnetic field compared to the traditional ECDM process.

Microwave drilling is an advanced machining process in which electromagnetic energy converted into thermal energy with the help of a metallic concentrator is used to create the desired shape in the work material. High strength electric field developed around the tooltip ionizes the dielectric media around the tooltip and results in plasma formation. High-temperature plasma ablates the material just beneath the tool tip to create the desired hole in the workpiece. In the present research work, micro-hole drilling on thermoset and thermoplastic-based composites using microwave energy in the air and transformer oil has been investigated. The drilling characteristics have been investigated in terms of the heat-affected zone, and overcut; a comparison has been made in air and transformer oil. The study revealed that drilling in the presence of dielectric-like transformer oil reduces the defects like HAZ and overcut significantly. It was also observed that thermal damage was more in thermoset-based composites as compared to thermoplastic-based composites.

Demand for increased production rates, better quality, and incorporation of green manufacturing practices has been continually challenging the manufacturers. This could be feasible by adopting high-speed machining (HSM) using eco-friendly cutting fluids but with careful process control. On these lines, the current paper explores process characteristics of the exotic superalloy Inconel 718 being turned at high speeds with tooling as coated carbide inserts and eco-friendly cutting fluid as water vapour. The experiments were carried out by varying three process parameters, viz. cutting speed, feedrate as well as water vapour pressure, following central composite design based on response surface methodology. A special tool holder with an in-built fluid supply channel was used to facilitate precise delivery of water vapour cutting fluid onto the machining zone. The process mechanics has been analyzed with the aid of the chip deformation coefficient as the same is a crucial indicator revealing the cutting fluid performance in machining as a result impacting the surface integrity, tool wear, machinability, etc. Analysis revealed that the response surface quadratic model for the chip deformation coefficient was statistically significant. The feedrate, vapour pressure, and the interaction between feedrate and vapour pressure were highly dominating factors influencing the chip deformation coefficient, with contributions of around 23.41%, 25.33% and 21.49%, respectively. An increase in vapour pressure was highly beneficial in lowering the chip deformation coefficient on account of water vapour’s better penetrability and performance into the machining zone. Overall usage of cutting fluid as water vapour within feasible HSM parametric ranges can be notably beneficial.

Aluminum-based metal matrix composites (MMC) are widely used in modern industries due to their lightweight, high strength, and superior hardness. In this study, silicon carbide (SiC) reinforced MMC has been fabricated using the stir casting method. Die-sinking EDM of fabricated MMC was performed using a copper (Cu) electrode. Experiments were carried out using the response surface methodology of box-behnken design (BBD) (RSM). The response surface plot was used to do parametric analysis on the effect of peak current (Ip ), gap voltage (Vg ), pulse-on-time (Ton), and duty factor(τ) on material removal rate (MRR) and surface roughness (Ra) using a second order regression model. The interaction effect of current with a pulse on time and duty factor has a substantial effect on MRR, while the interaction of current and voltage has a major impact on Ra, according to ANOVA. The increase of current increases both MRR and Ra. In the case of pulse-on-time, the value of Ra begins to decrease after 150 µs when the machining is performed at low voltage (40 V). 

Nanoparticles encompass great potential in the current era due to their small size. They are employed in a myriad of applications, from biotechnology to manufacturing and energy applications. The production of nanoparticles, therefore, has been a focus of interest for researchers since its inception. Amongst non-conventional methods for nanoparticle production, Spark Discharge has emerged as an effective and viable method. This review encapsulates various experiments and works done over the years on the application of the spark discharge method for the production of nanoparticles and postulates the prospects of future work in the field. Different ways to control nanoparticle size by altering different parameters such as dielectric medium spark frequency, the gap between electrodes, and energy per spark and flow rate have been explored. Contrast has been drawn between conventional and non-conventional processes of nanoparticle production. In conclusion, new non-conventional techniques and hybrid techniques for nanoparticle production with spark discharge methods have been discussed, along with the applications of nanoparticles in emission control, cooling and lubrication.

The manufacturing industry uses a variety of materials, including pure metals, alloys and composites. Due to the inability of pure metals to meet the demands of modern products, a transition in materials from pure metals to composites is taking place. Composite materials are invented to attain the desired properties, including lightweight, high strength, creep resistance, high corrosion resistance, fatigue resistance, high-temperature resistance and high wear resistance. Natural plant fibers, such as flax, hemp, kenaf, jute, sisal, coir and cotton, are a reliable source for producing composites because they have various advantages over synthetic fibers, including cheaper cost, low specific gravity, biodegradability, lightweight, fewer health hazards, availability, low-grade greenhouse emissions and high flexibility. Natural fiber-reinforced polymer composites (NF-RPC) are commonly utilized in automotive applications because they are lighter in weight, resulting in lower fuel consumption and greenhouse gas emissions. The mechanical properties of NF-RPC, such as tensile strength, Young’s modulus, flexural strength, hardness and many others, are affected by several factors, for example, fiber aspect ratio, the weight percentage of fiber, different orientations of fiber, usage of the fabrication process, chemical compositions of fiber and different pre-treatments of fiber. Therefore, in this article, some specific applications, mechanical properties, fabrication techniques of NF-RPC, and methods to enhance the properties of natural fibers, have been discussed. 

This paper presents the analysis of the Pineapple Leaf Fiber (PALF) reinforced composite used as a material for car bumpers. Impact analysis is performed on the modeled front car bumper at different fiber content, i.e., at the difference in the value of the fiber volume fraction, and the results are discussed. The objective is to model a car's rear bumper with considered dimensions, and analyze it by simulating in the circumstances of a crash, i.e., the impact is simulated against a rigid body at speed as per the standards of the vehicle. The natural fiber reinforced composite, which has good specific weight compared to synthetic fiber, results in a reduction in the weight of the whole body, resulting in less weight-to-volume ratio, when compared to the use of synthetic fibers and, therefore, can be considered as a material for car front bumper. There may certainly be a difference in performance, but depending on the required applications, the fiber-matrix bonding, and the aspect ratio can be varied. For PALF, the compensation for the low value of modulus can be done by having a very high aspect ratio, as the composite modulus is influenced by both young’s modulus and aspect ratio. In PALF reinforced Composites, the variation of fiber content affects the performance of the composites with less increase in overall weight compared to that of synthetic fibers.

Aluminium metal matrix composites are an exclusive class of materials that have improved performance parameters than their pure metal-based counterparts. These composites are widely used in structural, marine, aviation, defense and mining industries. Numerous synthetically derived hard ceramic reinforcements were widely researched for property enhancement of Aluminum Metal Matrix Composites, but, the exclusivity and the economic concerns of the synthetic reinforcements paved the way for widespread studies of agro-waste-based and industrial waste based Aluminum Metal Matrix Composites. In the current study, Bamboo Leaf Ash, an agro waste derived ceramic reinforcement based Aluminum Metal Matrix Composite; Al 7075/Bamboo Leaf Ash is fabricated using the Liquid Metallurgy Stir Casting technique with varying volume percentages from 2% to 8% of reinforcements in the matrix by weight. Mechanical and Microstructural characterization of the metal matrix composite is performed to ascertain the degree of improvement in properties of the composite compared to the base metal. The results from the study confirmed that a sound composite with higher hardness and strength was obtained. The microstructural characterization also confirmed that the grain structure is significantly refined, leading to property enhancement. 

Composite material is formed when one or more material is distributed or reinforced in a continuous second phase called a matrix. Composites have many superior properties, including low density, high strength-to-weight ratio, and good durability, which make them attractive in many industries. Composite materials have been used extensively in various applications. In any application where the strength-t- -weight ratio plays a vital and important role, Fibre Re-inforced Polymer’s (FRP) is the best material and offers the most efficient solution. Adhesive bonding is one of the most powerful joining techniques for FRP’s because of its high mechanical properties. It has applications in all the fields like aerospace, marine technology, defence systems, and automotive industries, as well as structural applications and sports. However, the mechanical performance is biased undesirably by contaminants, like release agents, and also an excess of matrix in the top layer. In order to generate the most appropriate surface pre-treatment, their effect on adhesively bonded joints of carbon and glass fibre re-inforced polymer composite laminates have been investigated. The adhesively bonded surfaces are treated with grit blasting and silica particle coating and later tested in order to determine the failure modes. It was found that the mechanical properties of adhesively bonded joints depend on the surface characteristics of the substrate. The results indicate that it is possible to increase the bond strength of the joints to maximum by various surface treatments. 

In this study, (Ta0.1Sm0.9)0.04Ti0.96O2 /Polyvinylidene fluoride composites were synthesized and analyzed for colossal dielectric properties. The ceramic powder was prepared by solid-state ceramic route, confirmed its phase purity through an X-ray diffractometer, and composites with different volume fractions were synthesized by finely dispersing the filler in the Polyvinylidene fluoride (PVDF) matrix followed by compression molding. Dielectric properties (dielectric constant and loss) up to 1 MHz were studied using an impedance analyzer. A high dielectric constant of 45 along with an acceptable loss of 0.089 was obtained for an optimum filler volume of 50% at 1 kHz. Hence the composites can be effectively used for energy storage applications.

CNT-reinforced polymer nanocomposites are emerging as a pioneer material for structural applications because of their enhanced mechanical properties as compared with neat polymers. The load transfer mechanisms and effective mechanical properties of these nanocomposites are strongly influenced by CNT parameters (volume fraction, length, aspect ratio, etc.), and thickness and mechanical properties of the interfacial region between the embedded CNT and the matrix. In this paper, modelling studies have been carried out to analyze the effects of these parameters on the effective elastic properties of a polymethyl methacrylate matrix embedded with single-walled CNTs. A three-phase continuum mechanics-based 3-D model of the nanocomposite is analyzed using the finite element method to predict the effect of an interphase on the elastic properties (elastic modulus and Poisson’s ratio) of the nanocomposite in longitudinal and transverse directions. The effect of the interphase having a varied modulus (ranging from that of CNT to that of matrix) through its thickness is also investigated. The Mori-Tanaka homogenization method is also applied to the three-phase and multi-phase micromechanical models to determine its feasibility in estimating the influence of the interphase on the elastic properties of the nanocomposite

This chapter presents the analysis of the vibration and deflection of a quadrilateral sandwich plate with a functionally graded core for different temperature conditions. The plate is made of functionally graded carbon nanotube-reinforced composite (FG-CNTRC), and results are obtained with the help of ANSYS software. The uniform distribution (UD), functionally grading V type distribution (FG-V), functionally grading X type distribution, and functionally grading O type distribution are the four different distributions of the reinforcements grading that are taken into consideration as a core in the direction of thickness (FG-O). The uniformly distributed grading is applied to the face plate for all the cases. Young's modulus, mass density, and Poisson's ratio are all important material properties calculated by the extended rule of mixture with the CNT efficiency parameter, accounting for size dependence. Detailed analysis is done in this paper to reveal the effect of volume fraction and temperature on the natural frequency and central deflection of the quadrilateral sandwich plate, and compared it with the results of a normal quadrilateral plate. Numerical results are obtained and presented using Ansys R17.2 and MATLAB. The results suggested that UD-type grading has the highest natural frequency and lowest central deflection compared to other types of functionally grading material.

We know that in today’s scenario, smart materials are in fame and are an important part of our daily life. Polymer nanocomposites (PNC) have attracted significant research and industrial interests due to their promising potential for versatile application. This nanocomposite technology has emerged from the field of engineering plastics and potentially expanded its application to structural materials, coatings, and packaging for medical products and electronic and photonic devices. The possibility of electrical and thermal conduction in a polymer matrix with low amounts of nanoparticles brings opportunities for highly demanding applications such as electrical conductors, heat exchangers, sensors, and actuators. The development of smart polymer nanocomposite (SPN) has been an area of high scientific and industrial interest in recent years, due to fantastic improvements achieved in these materials. SPN found potential applications in shape memory, self-healing, self-healing, self-cleaning, and energy harvesting. This paper mainly focuses on the most recent advances in polymer nanocomposites for everyday life applications, which are practically important and extremely useful. The applications of PNC are endless and still increasing rapidly due to their below-average cost and ease of manufacture. They make our lives more convenient and enjoyable. The main target is to study the applications of electrical and thermal properties of PNC for smart electronics materials.

The article examines and explores the impact of pre-strain on resistance to fatigue crack propagation (FCP) via analytical models. Most of the materials during service and processing have gone through preexisting strain due to strain-invigorating processes. It is an utmost priority of any low-weight and high strength structural requirement. The numerical study is based on aluminum alloy 7475 with T7375 heat treatment, which is a candidate material for the aerospace industry due to its mechanical properties. In this paper, virgin and pre-strained Aluminum7475, 2.54 & 5% are explored in the time-invariant loading for load or stress ratio (R) of 0, 0.1, and 0.4 (minimum stress/maximum stress) via fatigue crack propagation model Paris and Crack annealing model. The model selected for the study is rooted in small-scale yielding theory which is based on linear elastic fracture mechanics (LEFM) without crack closure and accounting crack closure (CL). The emphasis on crack closure behavior before and after the pre-strain of material. Effects of load ratio 0, 0.1, and 0.4 have been studied via crack closure models- Elber, Newman, and Virtual crack annealing model. A comparative study of fatigue crack propagation Paris & Crack annealing model forecast has been presented for virgin and strained conditions. The predictions are validated via experimental data. Prediction error analysis has been presented in the forecast and actual data.

Biosensors are analytical devices that are broadly used for the detection of chemical substances like tissue, organelles, cell receptors, enzymes, antibodies, etc. Smart materials respond to the external impulse, and convert the impulse to readable signals. Nowadays, smart materials are used in every requirement of a human being. The various kinds of smart materials are the subject of extensive investigation. This chapter examines the fundamental idea and practical use of smart materials in the biosensing industry.

The aim of the experiment is to investigate the tribological behavior of Brass and tin-based babbitt materials. The experiment is conducted on a pin-on-disk wear test machine at room temperature to analyze their effect on tribological behavior. The experiment is conducted at various operating factors like load, sliding time and sliding velocity under dry and lubrication conditions. Application of these materials is mostly found in automobile bearing, precise instrument, railway bearing, aerospace and heavy duty application. After conducting the experiment, it was noticed that tribological behavior slightly changes at elevated temperatures. The use of oil lubricant improves the tribological performance as compared to dry conditions by 18.56 times for tin-based babbitt alloy and by 2.19 times for brass material. Thus the performance of Brass under oil lubrication is superior to tin-based Babbitt due to its hardness. Under dry conditions, the wear rate of brass material is approximately four times that of wear in tin-based Babbitt; thus, the service life of tin-based Babbitt is longer than brass material under dry conditions.