Engineers have many materials to choose from when dealing with weight-related design constraints. The list includes aluminum, beryllium, magnesium, and titanium alloys as well as engineering plastics, structural ceramics, and polymer-, metal-, and ceramic-matrix composites. This chapter provides a brief overview of these lightweight materials, discussing their primary advantages along with their properties, behaviors, and limitations.

This chapter consists of three parts. The first part provides data and guidelines for selecting materials and processing routes. It compares the basic properties of metals, ceramics, and polymers, identifies important measures of performance, and discusses manufacturing processes and their compatibility with specific materials. The chapter then presents general guidelines for selecting lightweight materials, and concludes with a review of lightweight metals, plastics, and composites used in automotive applications.

Titanium aluminides are lightweight materials that have relatively high melting points and good high-temperature strength. They also tend to be stronger and lighter than conventional titanium alloys, but considerably less ductile. This chapter begins with a review of the titanium-aluminum phase diagram, focusing on the properties, compositions, and microstructures of alpha-2 Ti3Al alloys. It then describes the properties, microstructures, and compositions of orthorhombic, gamma, and near-gamma alloys as well as the processing methods and procedures normally used in their production.

This chapter describes the formability and forming characteristics of low-carbon sheet steels, coated sheet steels, stainless steels, and aluminum and magnesium alloys. It provides property data as well as flow stress curves for numerous grades of each material and explains how composition, microstructure, and processing methods influence forming behaviors.

Titanium is a lightweight metal with a density approximately 60% that of steel and, through alloying and deformation processing, it can be just as strong. It is readily available in many grades and forms and can be further processed using standard methods and techniques. This chapter provides a concise review of the capabilities of titanium and its design advantages over other materials. It includes information on properties and selection factors as well as applications.

Titanium is a lightweight metal used in a growing number of applications for its strength, toughness, stiffness, corrosion resistance, biocompatibility, and high-temperature operating characteristics. This chapter discusses the applications, metallurgy, properties, compositions, and grades of commercially pure titanium and alpha and near-alpha, alpha-beta, and beta titanium alloys. It describes primary and secondary fabrication processes, including melting, forging, forming, heat treating, casting, machining, and joining as well as powder metallurgy and direct metal deposition. It also compares and contrasts the properties of wrought, cast, and powder metal titanium products and discusses corrosion behaviors.

Transformation-induced plasticity (TRIP) steels are characterized by their excellent strength and high ductility, which allow the production of more complicated parts for lightweight automotive applications. This chapter provides an overview of the compositions, microstructures, processing, deformation mechanism, mechanical properties, hot forming, tempering, and special attributes of TRIP the steels.

Nonferrous metals are of commercial interest both as engineering materials and as alloying agents. This chapter addresses both roles, discussing the properties, processing characteristics, and applications of several categories of nonferrous metals, including light metals, corrosion-resistance alloys, superalloys, refractory metals, low-melting-point metals, reactive metals, precious metals, rare earth metals, and metalloids or semimetals. It also provides a brief summary on special-purpose materials, including uranium, vanadium, magnetic alloys, and thermocouple materials.

Improvement in processing, material substitution, light weighting, and recycling have contributed immensely to the cause of sustainability in the materials cycle. This chapter discusses some of the key indicators of sustainability that have direct relevance to advanced high-strength steels (AHSS) used in a vehicle. The discussion covers the major contributor to greenhouse gas emissions, production routes for manufacturing crude steel, and an optimized index guideline for selecting the best material. Details on the benefits of AHSS on the life cycle of vehicles are provided. The chapter also provides information on recycling and the economics of AHSS.

Tube hydroforming is a material-forming process that uses pressurized fluid to plastically deform tubular materials into desired shapes. It is widely used in the automotive industry for making exhaust manifolds, catalytic converters, shock absorber housings, and other parts. This chapter discusses the basic methods of tube hydroforming and the underlying process mechanics. It explains how to determine if a material is a viable candidate and whether it can withstand preforming or bending operations. It describes critical process parameters, such as interface pressure, surface expansion and contraction, and sliding velocity, and how they influence friction, lubrication, and wear. The chapter also provides information on forming presses and tooling, tube hydropiercing, and the use of finite elements to determine optimal processing conditions and loading paths.

This chapter is intended to identify materials, processes, and designs that will lead to great advances in powder-binder forming technologies. It discusses some of the structures obtained through these advances in powder-binder technologies such as binder jetting and extrusion-based additive manufacturing, including bound-metal deposition and fused-filament fabrication: oxidation-resistant high-temperature alloys, anisotropic structures, submicrometer-scale structures, surface hard materials, and artist metallic clays. Some of the advances discussed include the developments in process involving plastics, emulsions, ceramics, and porous structures and foams. Improvements in the design processes have led to the development of functional structures, controlled porosity, and bioinspired structures.

Roll forming is a process in which flat strip or sheet material is progressively bent as it passes through a series of contoured rollers. This chapter describes the basic configuration and operating principles of a roll forming line and the cross-sectional profiles that can be achieved. It explains how to determine strip width and bending sequences and identifies the cause of common roll-forming defects. It also discusses the selection of roll materials and explains how software helps simplify the design of roll forming lines.

This chapter provides an overview of the production and use of titanium and its significance as an engineering material. It begins by identifying important deposits and ores and assessing current and future production capacities and how they align with global consumption trends. It then describes the physical and mechanical properties of pure titanium and numerous grades of wrought titanium alloys and explains how they compare with other aerospace materials in terms of processing complexity and cost. The chapter also includes information on extractive metallurgy, current and emerging processes, product forms, and related costs.

Hardness tests provide valuable information about the quality of materials and how they are likely to perform in different types of service. This chapter covers some of the most widely used hardness testing methods, including Vickers, Rockwell, and Brinell tests, Shore scleroscope and Equotip hardness tests, and microindentation tests. It describes the equipment and procedures used, discusses the factors that influence accuracy, and provides hardness conversion equations for different types of materials. It also explains how hardness testing sheds light on anisotropy, machinability, wear, fracture toughness, and tensile strength as well as temperature effects, residual stress, and quality control.

This chapter discusses the particular corrosion problems encountered and the methods of control used in petroleum production and the storage and transportation of oil and gas up to the refinery. It begins by describing those aspects of corrosion that tend to be unique to corrosion as encountered in applications involving oil and gas exploration and production. This is followed by a section reviewing the methods of corrosion control, namely the proper selection of materials, protective coatings, cathodic protection systems, use of inhibitors, use of nonmetallic materials, and control of the environment. The chapter ends with a discussion on the problems encountered and protective measures that are based on the state-of-the-art as practiced daily by corrosion and petroleum engineers and production personnel.

This chapter describes the nature of the problems arising from using advanced high-strength steels (AHSS) and discusses potential remedies to minimize the adverse effects that may limit the adoption of AHSS in the automotive industry. The discussion provides information on press energy, springback, residual stress, die wear, hot forming, downgaging limits, welding, binders, draw beads, and tool material wear.

This chapter focuses on key requirements for obtaining third-generation advanced high-strength steels (AHSS). The discussion covers the microstructure design for AHSS, novel AHSS processing routes, the development of nanostructured AHSS, and the development of third-generation AHSS by the Integrated Computational Materials Engineering approach.

This chapter describes the various types of cushion systems used in forming presses and their effect on part quality. It begins with a review of the deep drawing process, explaining that wrinkling, tearing, and fracture are the result of excess or insufficient material flow, which can be prevented by maintaining the correct amount of holding force on the periphery of the blank. It then describes how blank holding force is generated in double-action presses and the extent to which displacement profiles can be adjusted on both the inner and outer slides. The discussion then turns to single-action presses that incorporate some type of cushion system. The chapters describes the many ways that cushion systems are implemented in forming presses and the force and displacement characteristics achievable with each method. It also explains how multipoint cushion systems are designed and how they facilitate uniform metal flow into the die cavity of large deep-drawn parts.

Metal-matrix composites can operate at higher temperatures than their base metal counterparts and, unlike polymer-matrix composites, are nonflammable, do not outgas in a vacuum, and resist attack by solvents and fuels. They can also be tailored to provide greater strength and stiffness, among other properties, in preferred directions and locations. This chapter discusses the processes and procedures used in the production of fiber-reinforced aluminum and titanium metal-matrix composites. It explains how the length and orientation of reinforcing fibers affect the properties and processing characteristics of both aluminum and titanium composites. It also provides information on fiber-metal laminates and the use of different matrix metals and reinforcing materials.