Uranium is a moderately strong and ductile metal that can be cast, formed, and welded by a variety of standard methods. This article presents an overview of the processing and properties of uranium and uranium alloys with a brief overview of the principal hazards and precautions associated with processing depleted uranium and methods to control mild radioactivity, chemical toxicity, and pyrophoricity. It also describes the classification and heat treatment of uranium and uranium alloys. Furthermore, the article provides graphical representation of the effect of alloy composition, cooling rate, and aging temperature on microstructure, crystal structure, and mechanical properties of uranium and uranium alloys.

Very high density materials are used for such applications as counterweights and radiation shields. This article focuses on the metallurgy, processing, properties, fabrication, design considerations, health and safety considerations, and applications of the most commonly used very high density materials: depleted uranium and tungsten and their alloys.

This article discusses the principles of physical metallurgy and metallography of depleted uranium. It describes the techniques involved in the preparation of thin foils for transmission electron microscopy and illustrates the resulting microstructure of uranium and uranium alloys, with the aid of black and white images. The article also provides information on the applications of etching and examination of uranium alloys, at both macro and micro scales, in characterizing the grain structures, segregation patterns, inclusions, and the metal flow geometries produced by solidification and mechanical working processes.

Heat treatment of depleted uranium (DU) alloys with 4.0 wt% or more molybdenum or equivalent is similar to that of dilute alloys. This article discusses the metallurgical characteristics and processing considerations of DU and its alloys, and describes the control of grain size and orientation using beta treatment. It lists the typical mechanical properties of DU as functions of the amount of cold work and hardness data of uranium rod, and describes the annealing of cold-worked DU. The article also describes the heat treatment of dilute alloys of DU, focusing on the three basic furnace designs used for heating or heat treating of unalloyed uranium: molten salt baths, inert-atmosphere furnaces, and vacuum furnaces. Finally, it presents procedures that are examples of heat treatment used to meet certain specifications of ultimate tensile strength, yield strength, and elongation.

Nuclear power plants benefit from thermal spray coatings for corrosion and erosion minimization and dimensional restoration of worn parts. This article provides a detailed discussion on the advantages of thermal spray coatings, fission reactor component coatings, and coatings for nuclear fuel processing before and after irradiation for power plant applications. Nuclear fusion research is divided into two primary fields of study categorized by the method for confining the fusion fuel: magnetic confinement fusion and inertial confinement fusion.

This article focuses on the basic metallurgy and machining parameters of classes of depleted and enriched uranium alloys. It provides information on the health precautions applicable to the machining of depleted uranium alloys. The article also discusses tool wear and the types of tools used in uranium alloy machining.

This article reviews general corrosion of uranium and its alloys under atmospheric and aqueous exposure as well as with gaseous environments. It describes the dependence of uranium and uranium alloy corrosion on microstructure, alloying, solution chemistry, and temperature as well as galvanic interactions between uranium, its alloys, and other metals. The article provides information on the atmospheric corrosion of uranium based on oxidation in dry air or oxygen, water vapor, and oxygen-water vapor mixtures depending upon particular storage conditions. The mechanism and morphology of hydride corrosion of uranium are discussed. The article provides information on environmentally assisted cracking, protective coatings, and surface modification of uranium and its alloys. It also summarizes the environmental, safety, and health considerations for their use.

This article begins with the discussion on the background of metal-matrix composites (MMC) and moves into a broad description of the general parameters affecting the corrosion of MMC. It discusses the primary sources of MMC corrosion that include galvanic corrosion between MMC constituents, chemical degradation of interphases and reinforcements, microstructure-influenced corrosion, and processing-induced corrosion. The article elaborates on the corrosion behavior of specific aluminum, magnesium, titanium, copper, stainless steel, lead, depleted uranium, and zinc MMCs systems. It concludes with a description on the corrosion control of MMCs using protective coatings and inhibitors.

Controlled-potential coulometry is a highly precise and accurate method primarily used for major constituent analysis of analyte substances such as alloys, compounds, nonmetallic materials and organic compounds. This article illustrates the apparatus required for controlled-potential coulometry, and provides information on its techniques and applications. It contains a table that lists the metals for which accurate methods have been developed and the basic electrochemistry of the procedures. The article explains that gold and uranium are the elements that are determined frequently in various sample types.

This article provides an introduction to the molecular fluorescence spectroscopy, and discusses the theory of fluorescence and its application to chemical analysis. It provides information on fluorescence that occurs in organic compounds and inorganic atoms and molecules. The article describes the instruments used in the spectroscopy, namely, radiation sources, sample holders, wavelength selectors, detectors, computers, and ratiometric instruments. The practical considerations include solvent effects, corrected spectra, wavelength calibration, temperature, and scattered light. The article also discusses the uses of some special techniques used in molecular fluorescence spectroscopy.

Skull melting refers to the use of furnaces with water-cooled crucibles that freeze a solid “skull” of material on the crucible wall. This article describes the basic components, operating pressure, advantages, and applications of vacuum arc and induction skull melting furnaces.

Molten salts, or fused salts, can cause corrosion by the solution of constituents of the container material, selective attack, pitting, electrochemical reactions, mass transport due to thermal gradients, and reaction of constituents and impurities of the molten salt with the container material. This article describes a test method performed using thermal convection loop for corrosion studies of molten salts. It discusses the purification of salts that are used in the Oak Ridge molten salt reactor experiment. The article also reviews the corrosion characteristics of nitrates/nitrites and fluoride salts with the aid of illustrations and equations.

Eutectoid and peritectoid transformations are classified as solid-state invariant transformations. This article focuses primarily on the structures from eutectoid transformations with emphasis on the classic iron-carbon system of steel. It reviews peritectoid phase equilibria that are very common in several binary systems. The addition of substitutional alloying elements causes the eutectoid composition and temperature to shift in the iron-carbon system. The article graphically illustrates the effect of various substitutional alloying elements on the eutectoid transformation temperature and effective carbon content. The partitioning effect of substitutional alloying elements, such as chromium, manganese, and silicon, in pearlitic steel is also illustrated.

Welding and joining processes are essential for the development of virtually every manufactured product. This article discusses the fundamentals of fusion welding processes, with an emphasis on the underlying scientific principles. It reviews the role of energy-source intensity and the width of the heat-affected zone in fusion welding processes. The article contains figures from which the properties of any heat source can be estimated readily.

This article provides a discussion on the process descriptions, processing conditions, and processing variables of the most common chemical methods for metal powder production. These methods include oxide reduction, precipitation from solution, and thermal decomposition. Methods such as precipitation from salt solution and gas, chemical embrittlement, hydride decomposition, and thermite reactions are also discussed. The article also discusses the methods used to produce powders electrolytically and the types of metal powders produced. The physical and chemical characteristics of these powders are also reviewed.

This article discusses the general characteristics, primary and secondary fabrication methods, product forms, and corrosion resistance of zirconium and hafnium. It describes the physical metallurgy of zirconium and its alloys, providing details on allotropic transformation and anisotropy that profoundly influences the engineering properties of zirconium and its alloys. Tables listing the values for chemical composition and tensile properties for nuclear and nonnuclear grades of zirconium are also provided.

This article describes various methods of electrochemical analysis, namely coulometry, electrogravimetry, voltammetry, electrometric titration, and nanometer electrochemistry. The discussion covers the general uses, sample requirements, application examples, advantages, and limitations of these methods. Some of the factors pertinent to electrochemical cells are also provided. In addition, the article provides information on various potentiometric membrane electrodes used to quantify numerous ionic and nonionic species.

Zirconium, hafnium, and titanium are produced from ore that generally is found in a heavy beach sand containing zircon, rutile, and ilmenite. This article discusses the processing methods of these metals, namely, liquid-liquid separation process, distillation separation process, refining, and melting. It also discusses the primary and secondary fabrication of zirconium and hafnium and its alloys. The article talks about the metallurgy of zirconium and its alloys with emphasis on allotropic transformation, cold work and recrystallization, anisotropy and preferred orientation, and the role of oxygen. It concludes by providing useful information on the applications of reactor and industrial grades of zirconium alloys.

This article provides a detailed account of the concepts and applications of neutron activation analysis (NAA), covering the basic principles and neutron reactions of NAA as well as calibration methods used for NAA. The discussion also covers the factors pertinent to analytical sensitivity achievable with NAA, common neutron sources, sample-handling technique, and automated systems of NAA. The categories of NAA covered are instrumental neutron activation analysis, epithermal neutron activation analysis, radiochemical neutron activation analysis, 14 MeV fast neutron activation analysis, delayed neutron activation analysis, and prompt gamma activation analysis.