This chapter discusses the key findings of an investigation into the failure of an aircraft engine fuel pump. It explains how investigators came to the conclusion that metal slivers from a heavily worn spring may have interrupted the flow of lubricant to one of the slipper pads, causing adhesive wear and the welding of slipper pad material onto the surface of a mating cam plate. Excessive friction between the slipper pads and cam plate, in turn, created a torsional overload that caused the camshaft to break. The chapter presents SEM images showing the wear pattern on one of the springs along with photographs of the damaged slipper pads and cam plate. It also includes an image of a copper flake found in one of the pistons and discusses the results of qualitative x-ray chemical analysis.

Induction heat treating is used in a wide range of applications. Typical uses, as described in this chapter, include the surface hardening of many types of shafts as well as gears and sprockets and the through-hardening of gripping teeth, cutting edges, and impact zones incorporated into various types of tools and track pins manufactured for off-highway equipment.

Unlike conventional quench and temper heat treatment, austempering is an iron and steel heat-treatment process that enhances mechanical properties through the isothermal transformation of austenite with a minimum amount of quenching stresses. This chapter begins with a discussion of austemperability requirements. Then outlines of austenitizing and austempering cycles and resultant microstructures are presented. This is followed by sections discussing the mechanical properties, advantages, limitations, machinability, process variants, and applications of austempered ductile iron (ADI). Information on the growth of premachined ADI components is also provided. Further, the chapter describes two slightly different systems for austempering: atmospheric-salt and salt-salt systems. Finally, it presents general guidelines for component designers, casting manufacturers, and heat treaters to apply ADI more widely and with improved success.

This chapter discusses the design and operating principles of various types of electromagnetic coils. It explains how induction coils are classified based on the direction of the eddy currents they induce in the workpiece and the corresponding orientation, whether longitudinal or transverse, of the associated magnetic flux. It then discusses the factors that influence coil design and selection, including coupling efficiency, frequency, the number and spacing of turns, and the use of flux intensifiers. It also includes images and illustrations of various types of coils and coil geometries for basic as well as special purpose applications.

Gaseous ferritic nitrocarburizing, like salt bath nitrocarburizing, involves the introduction of carbon and nitrogen into steel in order to produce a thin layer of iron carbonitride and nitrides, the "white layer" or compound layer, with an underlying diffusion zone containing dissolved nitrogen and iron (or alloy) nitrides. This chapter first presents the development and principles of the process. It then discusses the properties of gaseous ferritic nitrocarburized components. The chapter also presents the applications for the ferritic nitrocarburizing process. It provides an overview of the safety considerations.

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 discusses the effect of composition and cooling rate on the microstructure and properties of cast irons and explains how they differ from steel. It describes the conditions under which white, gray, mottled (chilled), and nodular (ductile) cast irons are produced, and examines the growth mechanisms and structural details that set them apart. It also discusses the formation of compacted (vermicular) graphite and malleable iron, and compares and contrasts the composition, properties, and heat treatment of whiteheart and blackheart malleable types.

This chapter discusses the characteristics, advantages, and disadvantages of nondestructive hardness testing methods for metals, including electromagnetic impulse testing, photothermal testing, scratch hardness testing, and ultrasonic contact impedance testing. It also discusses the use of ultrasound to determine the depth of hardening in a metal or alloy. The chapter reviews methods used to check and calibrate hardness testing machines and indenters and the use of hardness reference blocks for verification and calibration of test machines. It also addresses conversion of hardness values determined by one method to equivalent values for a different method.

This chapter provides a detailed discussion of salt bath nitrocarburizing. Process variations discussed include low-cyanide salt bath ferritic nitrocarburizing, salt bath nitrocarburizing plus post treatment, and the Kolene Nu-Tride process.

Coil design for induction heating has been developed and refined over time based on the theoretical principles applied in practice to several simple inductor geometries such as the classical solenoidal coil. This chapter reviews the fundamental considerations in the design of inductors and describes some of the most widely used coils and common design modifications. Specialty coil designs for specific applications are also discussed. The chapter concludes with sections devoted to coil fabrication and design of power-supply leads.

This article covers the metallurgy and properties of gray irons. It describes the classes or grades of gray iron, the types of applications for which they are suited, and the corresponding compositional ranges. It discusses the role of major, minor, and trace elements, how they are added, and how they affect various properties, behaviors, and processing characteristics. It explains how silicon, chromium, and nickel, in particular, improve high-temperature, corrosion, and wear performance.

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.

Heat treatment of steel involves a number of processes to condition the microstructure and obtain desired properties. This includes various methods namely, annealing, normalizing, and hardening by quenching and tempering. This chapter focuses on general heat treatment procedures and the applications of particular types or grades of carbon and low-alloy steels. The discussion covers carbon steel classification for heat treating, tempering of quenched carbon steels, and austempering of steel. In addition, the chapter discusses the effects of alloying and hardenability on steel and provides information on martempering of steel.

This chapter describes surface modification processes that go beyond conventional heat treatments, including plasma nitriding, plasma carburizing, low-pressure carburizing, ion implantation, physical and chemical vapor deposition, salt bath coating, and transformation hardening via high-energy laser and electron beams. The chapter compares methods and includes several example applications.