This chapter covers the friction and wear behaviors of plastics and elastomers. It begins by describing the molecular differences between the two types of polymers and their typical uses. It then discusses the important attributes of engineering plastics and their suitability for applications involving friction, erosion, and adhesive and abrasive wear. It also discusses the tribology of elastomers and rubber along with their basic differences and the conditions under which they produce Schallamach waves. It includes information on polymer composites as well.

This chapter provides an introduction to powder processing of binders and polymers. It sets the context for the remainder of the book by providing an overview of the topics discussed in the subsequent chapters and by providing introduction to powder-binder fabrication and customization of feedstock and describing the challenges in component production. The chapter also summarizes alphabetically a few key concepts in powder-binder processing.

Generally, binders consist of at least three ingredients: a backbone to provide strength (compounds such as polyethylene, polypropylene, ethylene vinyl acetate, and polystyrene); a filler, such as polyacetal and paraffin wax, to occupy space between particles; and additives, such as stearates, stearic acid, or magnesium stearate, as well as phosphates and sulfonates, to adjust viscosity, lubricate tooling, disperse particles, or induce binder wetting of the powder. In the case of binders deposited via ink jet printing, the binder contains solvents to lower the viscosity for easier jetting. The chapter provides a detailed description of these constituents. The requirements of a binder as well as the factors determining the physical and thermal properties of polymers are discussed. Then, two factors associated with solvation of polymers, namely solubility parameter and wetting, are covered. The chapter ends with information on the specification of polymers used in binders.

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.

This chapter includes a comprehensive set of definitions used in powder-binder processing.

This chapter discusses the structural classifications, molecular configuration, degradation, properties, and uses of polymers. It describes thermoplastic and thermosetting polymers, degree of polymerization, branching, cross-linking, and copolymers. It also discusses glass transition temperatures, additives, and the effect of stretching on thermoplastics.

This chapter covers the fatigue and fracture behaviors of ceramics and polymers. It discusses the benefits of transformation toughening, the use of ceramic-matrix composites, fracture mechanisms, and the relationship between fatigue and subcritical crack growth. In regard to polymers, it covers general characteristics, viscoelastic properties, and static strength. It also discusses fatigue life, impact strength, fracture toughness, and stress-rupture behaviors as well as environmental effects such as plasticization, solvation, swelling, stress cracking, degradation, and surface embrittlement.

This chapter describes the molecular structures and chemical reactions associated with the production of thermoset and thermoplastic components. It compares and contrasts the mechanical properties of engineering plastics with those of metals, and explains how fillers and reinforcements affect impact and tensile strength, shrinkage, thermal expansion, and thermal conductivity. It examines the relationship between tensile modulus and temperature, provides thermal property data for selected plastics, and discusses the effect of chemical exposure, operating temperature, and residual stress. The chapter also includes a section on the uses of thermoplastic and thermosetting resins and provides information on fabrication processes and fastening and joining methods.

This chapter reviews materials issues encountered in joining, including challenges involved in welding of dissimilar metal combinations; joining of plastics by mechanical fastening, solvent and adhesive bonding, and welding; joining of thermoset and thermoplastic composite materials by mechanical fastening, adhesive bonding, and, for thermoplastic composites, welding; the making of glass-to-metal seals; and joining of oxide and nonoxide ceramics to themselves and to metals by solid-state processes and by brazing. The classification, types, applications, and the mechanism of each of these methods are covered. The factors influencing joint integrity and the main considerations in welding dissimilar metal combinations are also discussed.

This chapter reviews the tests and procedures used for measuring hardness of plastics and elastomers. The conventional testing methods (Rockwell, Vickers, Brinell, and Knoop) used for testing of metals are based on the idea that hardness represents the resistance against permanent plastic deformation of the material to be tested. However, elastic deformation must be considered in hardness measurement of elastomers. This chapter discusses the equipment and processes involved in the durometer (Shore) test, the International Rubber Hardness Degree test, and other specialized tests. It presents the criteria that can be used to select a suitable hardness testing method for elastomers or plastics and describes processes involved in specimen preparation and equipment calibration.

This chapter discusses the use of thermoset and thermoplastic resins in polymer matrix composites. It begins by explaining how the two classes of polymer differ and how it impacts their use as matrix materials. It then goes on to describe the characteristics of polyester, vinyl ester, epoxy, bismaleimide, cyanate ester, polyimide, and phenolic resins and various toughening methods. The chapter also covers thermoplastic matrix materials and product forms and provides an introduction to the physiochemical tests used to characterize resins and cured laminates.

This chapter explains the distinction between materials and matter through the concept of microstructure. It presents the history of matter science and the establishment of metallography. The chapter provides an overview of the progress of steel technology, progress in synthetic polymers and ceramics, and establishment and development of materials science.

This chapter discusses the effect of fatigue on polymers, ceramics, composites, and bone. It begins with a general comparison of polymers and metals, noting important differences in microstructure and cyclic loading response. It then presents the results of several studies that shed light on the fatigue behavior and crack growth mechanisms of common structural polymers and moves on from there to discuss the fatigue behavior of bone and how it compares to stable and cyclically softening metals. It also discusses the fatigue characteristics of engineered and composited ceramics and ceramic fiber-reinforced metal-matrix composites.

This appendix provides supplemental information on the metallurgical aspects of atomic structure, the use of dislocation theory, heat treatment processes and procedures, important engineering materials and strengthening mechanisms, and the nature of elastic, plastic, and creep strain components. It also provides information on mechanical property and fatigue testing, the use of hysteresis energy to analyze fatigue, a procedure for inverting equations to solve for dependent variables, and a method for dealing with the statistical nature of failure.