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 covers the friction and wear behaviors of cast irons. It describes the microstructure and metallurgy of gray, white, malleable, and ductile cast irons, their respective tensile properties, and their suitability for applications involving friction, various types of erosion, and adhesive and abrasive wear.

This chapter concerns itself with the tribology of ceramics, cermets, and cemented carbides. It begins by describing the composition and friction and wear behaviors of aluminum oxide, silicon carbide, silicon nitride, and zirconia. It then compares and contrasts the microstructure, properties, and relative merits of cermets with those of cemented carbides.

This chapter provides guidelines and insights on the selection of materials, coatings, and treatments for friction and wear applications. It begins with a review of the system nature of tribological effects, the subtleties of friction, and the selection idiosyncrasies of the material systems and lubricants covered in prior chapters. It then presents a systematic approach for selecting tribomaterials, using an automotive fan motor as an example.

This chapter provides information on the biennial International Wear of Materials Conference, which is the inspiration for this book. It reviews the fundamentals of tribology, tribosystems, and related terminology. The glossary at the end of this chapter is intended to familiarize readers with some of the fundamental tribology terms that will be repeated throughout this book.

This chapter reviews the types of friction that are of concern in tribological systems along with their associated causes and effects. It discusses some of the early discoveries that led to the development of friction laws and the understanding that friction is a system effect that can be analyzed based on energy dissipation. It describes the stick-slip behavior observed in wiper blades, the concept of asperities, and the significance of the shape, lay, roughness, and waviness of surfaces in sliding contact. It explains how friction forces are measured and how they are influenced by speed, load, and operating environment. It also covers rolling contact and fluid friction and the effect of lubrication.

This chapter covers the friction and wear behaviors of copper alloys. It describes the compositions and forms of copper available and their suitability for applications involving friction, different types of erosion, and adhesive and abrasive wear.

This article focuses on friction and wear as they relate to polymeric materials, covering friction and wear applications for polymeric materials. The discussion covers the causes and mechanisms of friction, wear, and lubrication; different test methods developed to simulate friction and wear mechanisms; and friction and wear test data used for polymeric materials.

This chapter covers the different types of wear encountered in metalworking processes. It discusses the mechanisms involved in adhesive, abrasive, chemical, and fatigue wear and key contributing factors, including the composition and structure of tool and workpiece materials, the characteristics of contact surfaces, and loading forces imposed by the process. It describes the nature of metal transfer between tool and workpiece surfaces and the role of lubricants, coatings, and textures. It also discusses the use of wear maps, the effects of adhesion, and material-lubricant interactions.

This chapter covers the friction and wear behaviors of carbon, alloy, and tool steels. It begins a review of commercially available shapes and forms. It then describes the metallurgy and microstructure of various designations and grades of each type of steel and explains how it affects their performance in adhesive and abrasive wear applications and in environments where they are subjected to solid particle, droplet, slurry, and cavitation erosion and fretting damage.

This chapter covers the tribological properties of different types of oil, greases, solid lubricants, and metalworking and traction fluids. It explains how lubricants are made, how they work, and how they are applied and tested. It also discusses the fundamentals of lubrication and friction control, the relationship between viscosity and breakaway friction, and the factors that affect load-carrying capacity and service life.

This chapter covers coatings and treatments that are used to improve the friction and wear behaviors of materials. It describes modifications that work by hardening contacting surfaces, including heat treating, vacuum coating, thermal spray, and plating, and those that separate or lubricate surfaces, including solid film, chemical conversion, and vacuum coatings, surface oiling and texturing, and lubricating platings. It compares and contrasts methods based on thickness and depth and their relative effect on friction, erosion, and wear.

This chapter covers the mechanics and tribology of sheet metalworking processes, including shearing, bending, spinning, stretching, deep drawing, ironing, and hydroforming. It explains how to determine friction, wear, and lubrication needs based on process forces, temperatures, and strains and the effects of strain hardening on workpiece materials. It presents test methods for evaluating process tribology, describes lubrication and wear control approaches, and discusses the factors, such as surface roughness, lubricant breakdown, and adhesion, that can lead to galling and other forms of wear. It also provides best practices for selecting, evaluating, and applying lubricants for specific materials, including steels, stainless steels, and aluminum and magnesium alloys.

The porous structure of powder-metal materials, and thus the sintering method, has a significant impact not only on the properties of PM components, but also on how they respond to surface treatments and fabrication processes such as coating and joining. This chapter explains how the microstructure of PM parts achieved by different sintering methods influences the development of galvanized coatings and the mechanisms involved in sinter bonding and various welding and brazing processes. It presents and interprets the results of several studies in which PM materials, including iron, copper, stainless steel, brass, and bronze alloys, are joined by spot welding, projection welding, and solid-state welding as well as furnace and microwave brazing. It also examines the effects of ZrSiO 4 additions on the friction and wear behaviors of PM bronze brake-lining materials.

This chapter deals with the mechanics and tribology associated with the extrusion of bars, sections, and tubes. It covers direct and indirect extrusion processes in detail and demonstrates the use of important equations, relationships, and measurements for determining pressure, force, material flow, friction, die wear, heat generation, and lubrication requirements. The chapter also provides information on hydrostatic, friction-assisted, and severe plastic deformation extrusion processes, discusses the cause of instabilities and defects, and explains how to select and apply lubricants to minimize friction and die wear when extruding steel, aluminum, copper, and refractory metals.

This article provides details on several of the classifications of polymer wear mechanisms, using wear data and micrographs from published works. The primary goals are to present the mechanisms of polymer wear and to quantify wear in terms of wear rate. The discussion begins by providing information on the processes involved in interfacial and cohesive wear. This is followed by sections describing the wear process and applications of elastomers, thermosets, glassy thermoplastics, and semicrystalline thermoplastics. The effects of environmental and lubricant on the wear failures of polymers are then discussed. The article further includes a case study describing the tribological performance of nylon. It ends by presenting some examples of wear failures of plastics.

Forging is a deformation process achieved through the application of compressive stresses. During the stroke, pressures and velocities are continuously changing and the initial lubricant supply must suffice for the duration of the operation. Lubricant residues and pickup products also change with time, further complicating the analysis of friction and wear. This chapter provides a qualitative and quantitative overview of the mechanics and tribology of forging in all of its forms. It discusses the effects of friction, pressures, forces, and temperature on the deformation and flow of metals in open-die, closed-die, and impression-die forging and in back extrusion and piercing operations. It presents various ways to achieve fluid-film lubrication in upset forging processes and examines the cause of barreling, defect formation, and folding in the upsetting of cylinders, rings, and slabs. It also explains how to evaluate lubricants, friction, and wear under hot, cold, and warm forging conditions and how to extend die life and reduce defects when processing different materials.

This chapter discusses the effect of friction in the context of design. It explains how friction coefficients are determined and how they are used to make sizing and selection decisions. It covers practical issues associated with rolling friction, the use of lubricants, and the tribology of metal, ceramic, and polymer surfaces in contact. It also discusses the nature of rolling friction and provides helpful design guidelines.

This chapter covers the tribological properties of stainless steel and other corrosion-resistant alloys. It describes the metallurgy and microstructure of the basic types of stainless steel and their suitability for friction and wear applications and in environments where they are subjected to liquid, droplet, and solid particle erosion. It also discusses the tribology of nickel- and cobalt-base alloys as well as titanium, zinc, tin, aluminum, magnesium, beryllium, graphite, and different types of wood.