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Preface

We would like to present the book Light Weight Materials: Processing and Characterization. In the automotive industry, the need to reduce vehicle weight has led to extensive research efforts to develop aluminum and magnesium alloys for structural car body parts. In aerospace, the move towards composite airframe structures has led to an increased use of formable titanium alloys. All of the above-mentioned materials can be categorized into a group called “lightweight materials”. The distinguishing feature of lightweight materials is their low densities, ranging from as low as 0.80 g/cm³ for unfilled polymers to as high as 4.5 g/cm³ for titanium. Although the density of titanium is higher than that of unfilled polymers, it is significantly lighter than metals: alloy steel (7.86 g/cm³) and superalloys (7.8–9.4 g/cm³). In a nutshell, lightweight materials exhibit a wide range of properties and therefore offer a wide range of applications.

This book primarily aims to provide researchers and students with an overview of the recent advancements in the processing, manufacturing and characterization of lightweight materials, which promises increased flexibility in manufacturing in tandem with mass communication, improved productivity and better quality. It has a collection of chapters contributed by eminent researchers who focus on the topics associated with lightweight materials, including the current buzzword composite materials. This book provides the recent advancements in the processing, manufacturing and characterization of lightweight materials and hence would be a panacea in all areas of lightweight materials.

This book has two major objectives. Firstly its chapters by eminent researchers in the field enlighten readers about the current status of the subject. Secondly, as the densities vary a lot so do the applications ranging from automobile, aviation to bio-mechatronics; hence, this book would serve as an excellent guideline for people in all of these fields.

The chapters of this book are divided into three parts, namely Part 1: Manufacturing Processing Techniques, Part 2: Characterization and Part 3: Analysis.

Part 1 contains Chapters 1–3, Part 2 contains Chapters 4 and 5 and Part 3 contains Chapters 6–8.

Chapter 1 explains an advanced technique called additive manufacturing (AM), which is predominantly known as 3D printing and rapid prototyping. It is an on-demand production without any dedicated apparatus or tooling, which allows breakthrough performance and supreme flexibility in industries. The aerospace industry is the primary user of AM, as it enables it to create complex user-defined part design and fabricate with different lightweight materials without wastage of raw materials, reducing the time and cost of production. This chapter provides in-depth knowledge about its classification and selection process for various applications required by engineering industries, especially in the aerospace industry.

Chapter 2 mainly deals with the manufacturing of polymer gears. Polymer gears are widely used in medical devices upon which human lives depend. In addition, they are useful in other applications such as in the automotive and manufacturing industries. A precise gear of better design and effective manufacturing process decides its long-term application, strength and property. Polymer gears can be fabricated with the same machining process as metal gears, usually milling or hobbing from a blank. However, for lightweight materials, such as polymers, it is preferable to be either fabricated by injection molding or machined from a rod (additive manufacturing). The details of such manufacturing techniques are presented in this chapter.

Chapter 3, the last chapter of Part 1, discusses in detail reinforcing, performance analysis, processing and characterization of various methods of polymer welding, i.e. laser welding, infrared welding, spin welding, stir welding, and vibration welding. This chapter also covers various alloys of aluminum for lightweight applications and the current status of polymer composite applications in industries and future prospects. This chapter highlights the complications related to fusion, heat transfer and joint strength, as well as their solutions with the future prospect of polymer welding empowering polymers to be an absolute substitute for metal, which can be achieved by understanding the concept of dissimilar welding for joining polymer composites with metals and their controlling factors, and by selecting an appropriate welding process for various types of polymers.

Chapter 4, the first chapter of Part 2, provides the reader with an idea of fabrication and a description of the processing techniques of natural-based composites for light body vehicle applications. In doing so, the genetic equation for modeling tool flank wear is developed using experimentally measured flank wear values and genetic programming. Using these results, the genetic model presenting the connection between cutting parameters and tool flank wear is extracted. Then, based on a defined machining performance index and the obtained genetic equation, optimum cutting parameters are determined. This chapter concludes that the proposed modeling and optimization methodology offer the optimum cutting parameters and can be implemented in real industrial applications.

Chapter 5 presents the response surface methodology, an optimization technique, to design a catalytic cracking experiment of plastic waste. The catalyst-to-feedstock ratio, the operating temperature and the reaction time were chosen as an effective parameter of the catalytic cracking process. The characterization of the obtained liquid product was performed using the Fourier transform with infrared (FTIR) spectra, gas chromatography with mass spectrometry (GC/MS) analysis and physico-chemical analysis. This chapter concludes that the developed quadratic model is well fit to the experimental domains and predicts operating conditions that are most suitable for conducting catalytic cracking experiments under recycling techniques of lightweight materials, especially plastics.

Chapter 6, the first chapter of Part 3, discusses laser welding. The uniqueness of this chapter is the way it has dealt with the subject. The finite element analysis was used to select suitable models for the Gaussian beam profile and the application of the Frustum model to conduction mode welding and keyhole laser welds. Temperature and stress analysis was carried out within and around the weld region. This chapter discusses the analytical comparative approximation of different model approaches applicable to the laser weld process, and indicates that the parametric study information will be useful to the engineers of nuclear fabrication applications in finalizing different components.

Chapter 7 elaborates on the effect of formability parameters on tailor-welded blanks of lightweight materials. The product finds its maximum application in the automotive manufacturing industry. It is quite common that different materials with varying cross-sections are used based on the requirements in aerospace and automotive industries. To manage the herculean task of organizing this, researchers have enthusiastically proposed a tailor-made welded blanks (TWB) strategy, and in many automotive industries this technique has been adopted. This chapter suggests testing the formability of tailor-welded blanks with various light alloy sheets used in the aerospace and automotive industries. An overall review of various parameters that affect the formability of tailor-welded blanks is presented in this chapter, so that other investigators can rely on the same for more critical observations in this field.

Chapter 8, the last chapter of this section, presents the various ways of optimizing a vehicle body, such as shape optimization for aerodynamics and aesthetics, and weight of materials to be used for fuel efficiency, material conservation, recyclability and others. This chapter considers a product called “B-pillar”, one of the critical structural support members of sedan cars. They have replaced the existing material with a composite, mainly to overcome the stress developed due to the system as it is a structural member and to safeguard the occupant in the case of a side crash. Different mechanical properties such as tensile, compression and bending strength, as well as water absorption, were measured. The model of the sedan car B-pillar panel developed was analyzed for impact and crush simulation. It concluded that a composite can be used for the outer panel of B-pillar, which results in reduced vehicle weight and fuel consumption and increased energy absorption.

First and foremost, we would like to thank God. It was your blessing that provided us with the strength to believe in passion and hard work and to pursue our dreams. We thank our families for having the patience with us for taking yet another challenge that decreased the amount of time we could spend with them. They are our inspiration and motivation. We would like to thank our parents and grandparents for allowing us to follow our ambitions. We would like to thank all the contributing authors, as they are the pillars of this structure. We would also like to thank them for believing in us. We would like to thank all of our colleagues and friends in different parts of the world for sharing their ideas helping us to shape our thoughts. We will be satisfied with our efforts when the professionals concerned with all the fields related to lightweight materials are benefitted.

We owe a huge thanks to all of our technical reviewers, Editorial Advisory Board members, Book Development Editor and the team at ISTE Ltd for their availability to work on this huge project. All of their efforts helped us to complete this book, and we could not have done it without them.

Last, but definitely not least, we would like to thank all of the individuals who have taken time out and helped us during the process of editing this book. Without their support and encouragement, we would have probably given up the project.

Kaushik KUMAR

Bathini SRIDHAR BABU

J. Paulo DAVIM

September 2020