This article reviews the history of superconductivity from its discovery in the early 1900s to the renewed interest in the mid-1980s spurred by the development of high-temperature superconducting devices. It identifies some of the materials in which superconductivity has been observed, including metals and alloys, compounds, and oxides, and discusses their properties as well as potential applications. The article also explains how various superconducting materials are produced and provides a foundation for understanding the basic operating principles.

Recrystallization is to a large extent responsible for their final mechanical properties. This article commences with a discussion on static recrystallization (SRX) and dynamic recrystallization (DRX). The DRX includes continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX). The article discusses the assumptions and simplifications for the Avrami analysis. It describes the effects of nucleation and growth rates on recrystallization kinetics and recrystallized grain size based on the Johnson-Mehl-Avrami-Kolmogorov model for static recrystallization. The article reviews the kinetics of DRX with the aid of the Avrami relations. It considers the basic framework of the mesoscale approach for DDRX, including the three basic equations for grain size changes, strain hardening and dynamic recovery, and nucleation. The article explains the mesoscale approach for CDRX to predict microstructural evolutions occurring during hot deformation, along with an illustration of the main features of the CDRX mesoscale model.

This article provides a summary of the concepts discussed in the articles under the Section “Introduction and Basic Theory of Wear” in ASM Handbook, Volume 18, Friction, Lubrication, and Wear Technology .

This article describes the applications of induction heat treatment of metals, including normalizing, annealing, hardening, and tempering and stress relieving. It discusses the simulation techniques of the electromagnetic and thermal processes that occur during induction heat treating. The article explains the finite-difference method, finite-element method, mutual impedance method, and boundary-element method for the numerical computation of the induction heat treating processes. It also discusses the direct and indirect coupling approaches for coupling the electromagnetic and heat-transfer problems. Modern computer simulation techniques are capable of effectively simulating electromagnetic and thermal phenomena for many processes that involve electromagnetic induction. The article considers the challenges faced by developers of modern simulation software.

Semisolid metal (SSM) processing, also known as semisolid metal casting, semisolid forming, or semisolid metal forging, is a special die casting process. This article discusses the origin and advantages of the SSM processing. It describes three major semisolid processing routes: thixocasting, rheocasting, and thixomolding.

This article analyzes the estimates of the cost of corrosion, made in various countries at various times. The data are extrapolated to a 2004 base and then projected to the global economy. The chronological order of the countries are the United States of America, the United Kingdom, Australia, Japan, Canada, Germany, Poland, South Africa, Czechoslovakia, Belgium, Netherlands, Sweden, Finland, the Union of Soviet Socialist Republics, Kuwait, India, and the Basque Region.

Arc welding is one of several fusion processes for joining metals. This article introduces the fundamentals of arc welding and provides a summary of its history and early discoveries.

This article provides an overview of two major classes of bearings: rolling bearings and sliding, or plain, bearings. It reviews the experimental data resulted from testing of rolling and sliding bearing materials with illustration. The article presents a table that summarizes rolling contact fatigue test methods that ASTM published in STP 771. It also describes the role of lubrication in the bearings.

This article introduces the concepts of linear-elastic fracture mechanics (LEFM) and elastic-plastic fracture mechanics (EPFM). It reviews the fracture mechanics of ceramics and ceramic matrix composites (CMCs). The article describes some fracture toughness measurement techniques used on ceramics and CMCs: single edge notch bending, compact tension, double cantilever beam testing, chevron notch methods, and double torsion. It presents descriptions organized by their specimen types, and includes the advantages and disadvantages, as well as the experimental control schemes employed for each specimen type.

One of the most frequently cited advantages of ceramics in dentistry relates to aesthetics, and the same applies for dental implants. Zirconia has emerged as the material of choice for nonmetal implants. This article introduces the reader to zirconia as an implant material, its properties, manufacturing processes, and the particular surface modifications and treatments that have rendered its surfaces biologically compatible with peri-implant soft and hard tissues.

Casting is one of the most economical and efficient methods for producing metal parts. In terms of scale, it is well suited for everything from low-volume, prototype production runs to filling global orders for millions of parts. Casting also affords great flexibility in terms of design, readily accommodating a wide range of shapes, dimensional requirements, and configuration complexities. This article traces the history of metal casting from its beginnings to the current state, creating a timeline marked by discoveries, advancements, and influential events. It also lists some of the major markets where castings are used.

Induction hardening of steel components is the most common application of induction heat treatment of steel. This article provides a detailed account of electromagnetic and thermal aspects of metallurgy of induction hardening of steels. It describes induction hardening techniques, namely, scan hardening, progressive hardening, single-shot hardening, and static hardening. The article discusses the techniques used to control the heat pattern, and provides a brief review of quenching techniques used in the induction hardening. It provides guidelines for selecting the frequency and power for induction hardening, and describes common methods for measuring case depth, such as optical and microhardness, and surface hardness. It provides information on some complications and ambiguities associated with these measurements. The article also discusses the commonly used non-destructive testing methods, namely, magnetic particle testing, ultrasonic testing, and eddy current testing to evaluate induction-hardened components.

Solid-state transformations occurring in a weld are highly nonequilibrium in nature and differ distinctly from those experienced during casting, thermomechanical processing, and heat treatment. This article provides a description of the special factors affecting transformation behavior in a weldment. It reviews the heat-affected and fusion zones of single-pass and multi-pass weldments. The article also includes a discussion on the welds in alloy systems, such as stainless steels and aluminum-base, nickel-base, and titanium-base alloys.

This article provides a summary of the conventional technologies used for titanium powder production. It focuses on the various processes for titanium powder production, namely, Hunter, Kroll, Armstrong, MER, TIRO, FFC-Cambridge, Chinuka, and CSIR processes. Employment of titanium powder significantly improves the synthesis of titanium and its alloys.

This article provides the framework for the investigation of bridge failures. It explains the types of bridge loading and presents the regulatory provisions for bridges. Some bridge failures in the U.S. that resulted in significant changes in bridge manufacturing, design, regulation, and/or maintenance are also discussed. In addition, the article provides information on traffic damage and fatigue cracking that result in bridge failures. The need for steels with better fracture toughness in bridge design is also discussed.

Rehabilitation is the process of repairing or modifying reinforced concrete structures to a desired useful condition. This article describes the operational steps for the structural assessment of reinforced concrete structures. It discusses the classification of composite materials reinforcing systems for strengthening reinforced concrete structures, such as shop-manufactured and field-manufactured structures. The article reviews the materials property requirements for designing reinforcing systems to strengthen the reinforced concrete structures. It discusses the fiber-reinforced polymer (FRP)-reinforced concrete behavior that depends on flexural, shear, or axial failures. Surface preparation procedures for rehabilitation techniques of reinforced concrete structures using bonded FRP materials are also discussed. The article provides information on the applications of rehabilitation of concrete structures. It explains data recording and acceptance criteria for rehabilitation of concrete structures with composite materials.

Solid-state transformations occurring in a weld are highly nonequilibrium in nature and differ distinctly from those experienced during casting, thermomechanical processing, and heat treatment. This article focuses on welding metallurgy of fusion welding of steels and highlights the fundamental principles that form the basis of many of the developments in steels and consumables for welding. Examples in the article are largely drawn from the well-known and relatively well-studied case of ferritic steel weldments to illustrate the special physical metallurgical considerations brought about by the weld thermal cycles and by the welding environment. The article provides information on welds in other alloy systems such as stainless steels and aluminum-base, nickel-base, and titanium-base alloys.

Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique that leverages the principles of ultrasonic welding, mechanized tape layering, and computer numerical control (CNC) machining operations to create three-dimensional metal parts. This article begins with a discussion on the process fundamentals and process parameters of UAM. It then describes metallurgical aspects in UAM. The article provides a detailed description of a wide range of mechanical characterization techniques of UAM, namely tensile testing, peel testing, and pushpin testing. The article ends with information on sensor embedding.