This chapter examines the microstructure of metallic components produced by casting and compares them with microstructures achieved by means of powder metallurgy. It shows how metals and alloys obtained by various processing routes differ in terms of grain size, secondary phases, oxide and carbide dispersions, porosity, dendritic formation, and properties such as hardness, toughness, tensile strength, and yield strength.

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.

Ductile iron has far superior mechanical properties compared to gray iron as well as significantly improved castability and attractive cost savings compared to cast steel. This chapter begins with information on graphite morphology and matrix type. It then discusses the advantages and applications of ductile iron. Next, the effects of various factors on the grades, chemistry, matrix, and mechanical properties of ductile iron are covered. This is followed by a section detailing the ductile iron treatment methods and the quality control methods used. Guidelines for gating and feeder design are then provided. Further, the chapter addresses the technology of ductile iron castings, including the performance and geometric attributes, molding and core-making processes used, material grades, mechanical properties, and chemical compositions of a few applications. Finally, it describes ductile iron casting defects and presents practical cases of problem-solving.

The hardenability of steel is governed almost entirely by the chemical composition (carbon and alloy content) at the austenitizing temperature and the austenite grain size at the moment of quenching. This article introduces the methods to evaluate hardenability and the factors that influence steel hardenability and selection. The discussion covers processes involved in Jominy end-quench test for evaluating hardenability. The effect of carbon on hardenability data and the effect of alloys on hardenability during quenching and on the tempering response (after hardening) are also discussed. In addition, the article provides information on the hardenability limits of H-steels after a note on hardenability correlation curves and Jominy equivalence charts.

This chapter describes some of the most effective tools for investigating boiler tube failures, including scanning electron microscopy, optical emission spectroscopy, atomic absorption spectroscopy, x-ray fluorescence spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. It explains how the tools work and what they reveal. It also covers the topic of image analysis and its application in the measurement of grain size, phase/volume fraction, delta ferrite and retained austenite, inclusion rating, depth of carburization/decarburization, scale thickness, pearlite banding, microhardness, and hardness profiles. The chapter concludes with a brief discussion on the effect of scaling and deposition and how to measure it.

This chapter elucidates the indispensable role of characterization in the development of cold-sprayed coatings and illustrates some of the common processes used during coatings development. Emphasis is placed on the advanced microstructural characterization techniques that are used in high-pressure cold spray coating characterization, including residual-stress characterization. The chapter includes some preliminary screening of tool hardness and bond adhesion strength, as well as a distinction between surface and bulk characterization techniques and their importance for cold spray coatings. The techniques covered are optical microscopy, X-Ray diffraction, scanning electron microscopy, focused ion beam machining, electron probe microanalysis, transmission electron microscopy, and electron backscattered diffraction. The techniques also include electron channeling contrast imaging, X-Ray photoelectron spectroscopy, X-ray fluorescence, Auger electron spectroscopy, Raman spectroscopy, oxygen analysis, and nanoindentation.

Induction hardened steels are often tempered to increase their ductility and relieve quenching stresses. During tempering, martensitic microstructures supersaturated with carbon decompose into a more stable, ductile form. This chapter discusses the transformations associated with the tempering process and their effect on ductility as well as other properties. It describes the structural and compositional changes that occur during the four stages of tempering, the relative influence of time and temperature, and how tempering affects the hardness of various grades of steel. The chapter discusses the practice of both furnace and induction tempering, describing where and how they are used, their tempering characteristics, strengths and limitations, and operating parameters. It also discusses the use of residual heat tempering, a self-tempering process.

This appendix provides tempering curves for common grades of steel, including 1045, 1144, 4140, 4150, and E52100.

This appendix provides hardenability curves for several H-steels (1045H, 4130H, 4140H, 4142H, 4145H, 4340H, 5160H, 8620H) and one alloy steel (E52100).

The properties of martensite and the mechanisms that govern its formation are the key to understanding hardness and the hardenability of carbon steel. Martensite is a transformation product of austenite that requires rapid cooling to suppress diffusion-dependent transformation pathways. This chapter describes the conditions that must be met for martensite to form. It discusses the role of quenching and the factors that affect cooling rate, including heat transfer, thermal diffusivity, emissivity, and section size. It defines hardenability and explains how to quantify it using the Grossmann-Bain approach or Jominy end-quench testing. It also explains how hardenability can be improved through the addition of boron, phosphorus, and other alloys.

This appendix is a compilation of approximate equivalent hardness numbers and tensile strengths for carbon and alloy steels in the annealed, normalized, and quenched-and-tempered conditions.

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.

This chapter discusses the factors that govern the mechanical properties of titanium, beginning with the morphology of the alpha phase. It explains that the shape of the alpha phase has a significant effect on many properties, including hardness, tensile strength, toughness, and ductility as well as creep, fatigue strength, and fatigue crack growth rate. It also discusses the influence of other titanium phases and the properties of titanium-based intermetallic compounds, metal-matrix composites, and shape-memory alloys.

The mechanical behavior of a material, in the most practical sense, is how it deforms or breaks under load; in other words, how it responds when stressed. This chapter provides a brief review of the properties associated with mechanical behavior, including stress, strain, elasticity, plastic deformation, ductility, hardness, creep, fatigue, and fracture. It also describes the primary components of a Charpy impact tester and the role they serve.

This chapter discusses the stress-strain response of materials, how it is measured, and how it used to set performance expectations. It begins by describing the common tensile test and how it sheds light on the elastic design of structures as well as plasticity and fracture behaviors. It explains how engineering and true stress-strain curves differ, how one is used for design and the other for analyzing metal forming operations. It discusses the effect of holes, fillets, and radii on the distribution of stresses and the use of notch tensile testing to detect metallurgical embrittlement. The chapter also covers compression, shear, and torsion testing, the prediction of yielding, residual stress, and hardness.

This appendix includes tables and figures that provide approximate Brinell equivalent hardness numbers for steels.