This chapter discusses steel’s compositions, metallurgical phases, microstructures, and heat treatments. It then presents the structure-property relationships of steel. The chapter describes the deformation and strengthening mechanisms of steel. It also presents an overview of deformation processing and annealing.

This chapter presents the nomenclature, generations, thermomechanical processing, microstructure development, and mechanical properties of advanced high-strength steels.

Dual-phase (DP) steels have the widest usage in the automotive industry because of their excellent combination of strength and ductility. This chapter presents the composition, microstructure, mechanical properties, formability, and attributes of DP steels. It also discusses the basic approaches for the commercial production of DP steels.

This chapter presents a discussion on the compositions, microstructures, processing, deformation mechanism, mechanical properties, formability, and attributes of complex-phase steels.

This chapter presents the composition, microstructure, processing, deformation mechanism, mechanical properties, formability, and attributes of transformation-induced plasticity steels.

Martensitic (MS) steel is produced by quenching carbon steel from the austenitic phase into martensite. This chapter presents the compositions, microstructures, processing, deformation mechanism, mechanical properties, hot forming process, and attributes of MS steels.

This chapter presents an overview on the twins and stacking faults. It then provides an overview of the compositions, microstructures, thermodynamics, processing, deformation mechanism, mechanical properties, formability, and special attributes of twinning-induced plasticity steels.

Austenitic stainless steels are iron-base alloys containing more than 50% Fe, 15 to 26% Cr, and less than 45% Ni. This chapter provides a discussion on the types, compositions, microstructures, processing, deformation mechanism, mechanical properties, formability, and special attributes of austenitic stainless steels.

This chapter presents a review of some of the global development and deployment of advanced high-strength steels (AHSS). It discusses collaboration projects between government, industry, and academia and summarizes research that has focused on the influence of alloy composition on the microstructure evolution during plastic deformation and the resulting mechanical properties.

This chapter summarizes the microstructural basis of conventional high-strength steels (HSS) and the three generations of advanced high-strength steels (AHSS). It presents the requirements of a third generation advanced high-strength steel and its microstructural design. The chapter also includes a discussion about novel AHSS processing routes: quenching, partitioning, and double-stabilization thermal cycling.

This chapter presents a discussion on the grain sizes and boundaries in nanocrystals. It discusses the third-generation nanotechnology in advanced high-strength steels.

This chapter explains how to measure the shape, size, microstructure, and composition of powders as well as their flowability and crystallization behavior. It presents detailed workflows and calculations based on SEM, TEM, FESEM, and STEM imaging, x-ray diffraction, differential scanning calorimetry, EDS and EELS spectroscopy, and powder sieving. It also discusses the measurement of crystallite size, lattice mismatch, and crystallinity and the relationship between surface area and flowability.

This chapter provides an overview of sintering techniques and the microstructures and properties that can be achieved in different material systems. It covers conventional furnace sintering, microwave and laser sintering, hot and hot-isostatic pressing, and spark plasma sintering. It describes the advantages and disadvantages of each method, the mechanisms involved, and the effect of sintering parameters on the density, grain size, and mechanical properties of titanium and tungsten heavy alloys, stainless steel, cemented carbides, ceramics, composites, and rare earth magnets.

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.

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 reviews some of the differences between powder metallurgy and additive manufacturing and explains how they influence the microstructure and properties of various alloys and the formation of defects in manufactured parts.

This chapter discusses the advantages and limitations of 3D printing technology for the production of batteries and supercapacitors. It explains how 3D printing methods facilitate the build of microdevices with hierarchical nanoarchitectures and controlled microstructure. It also reviews recent progress in fabricating electrodes and electrolytes using 3D-printed functional materials.

Phase diagrams serve as a map to the phases present in an alloy at different temperatures and compositions. They also help in assessing mechanical properties, selecting heat treat temperatures, warning of possible solidification problems, and identifying routes for creating desired microstructures. This chapter familiarizes readers with the information contained in binary phase diagrams and the methods used to extract it. It explains how thermocouple measurements are used to determine liquidus, solidus, and eutectic reaction lines, how differential scanning calorimetry shows where phase reactions occur, and how x-ray diffraction identifies the actual phases present. It demonstrates the use of tie lines for determining phase composition at different temperatures and the application of the level rule to calculate phase fractions. It also discusses the CALPHAD method and presents computed binary phase diagrams that account for the presence of inclusions, oxygen content, and secondary phases.