The electroplating of platinum-group metals (PGMs) from aqueous electrolytes for engineering applications is limited principally to palladium and, to a lesser extent, to platinum, rhodium, and thin layers of ruthenium. This article provides a discussion on the plating operations of these PGMs along with the types of anodes used in the process.

Precious metals include gold, silver, and six platinum-group metals, namely, platinum, palladium, ruthenium, rhodium, osmium, and iridium. This article focuses on the consumption, trade practices, properties, product forms, and applications of these metals and their alloys.

This article characterizes the corrosion resistance of precious metals, namely, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. It provides a discussion on the general fabricability; atomic, structural, physical, and mechanical properties; oxidation and corrosion resistance; and corrosion applications of these precious metals. The article also tabulates the corrosion rates of these precious metals in corrosive environment, namely, acids, salts, and halogens.

Precious metals are of inestimable value to modern civilization. This article discusses the resources and consumption, trade practices, and special properties of precious metals and its alloys, including ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold, and tabulates the industrial applications of precious metals. It provides information on the commercial forms (wire, rod, sheet, strip, ribbon, and foil) and uses of precious metals, including semifinished products, precious metal powders, industrial uses, coatings, and jewelry.

This article explains how to prepare precious metal test samples for metallographic examination. It discusses cutting, mounting, grinding, polishing, and etching and addresses some of the challenges of working with small, relatively soft specimens. It includes dozens of example micrographs, comparing and contrasting the microstructural features of gold, platinum, iridium, palladium, and ruthenium-base alloys. It examines pure gold, intermetallic gold compounds, gold and platinum jewelry alloys, platinum-containing shape memory alloys, and alloys consisting of platinum, aluminum, and copper.

Metallic nonelectrolytic alloy coatings produced from aqueous solutions are commercially used in several industries, including electronics, aerospace, medical, oil and gas production, chemical processing, and automotive. Nonelectrolytic coating systems use two types of reactions to deposit metal onto a part: electroless and displacement. This article explains the various types of electroless and dispersion alloy coating systems. It provides information on the processing of parts, process control, deposit analysis, and equipment used for coating nonelectrolytic displacement alloys. The article concludes with a discussion on the safety and environmental concerns associated with nonelectrolytic deposition processes.

Electrical contacts are metal devices that make and break electrical circuits. This article provides information on materials selection criteria and failure modes of make-break contacts. It describes the property requirements for make-break arcing contacts, namely, electrical conductivity, mechanical properties, chemical properties, fabrication properties, and thermal properties. The article presents a brief note on brush contact materials and their interdependence factors for sliding contacts. It also describes the type of commercial contact materials for electrical contacts, namely, copper metals, silver metals, gold metals, metals of the platinum group, precious metal overlays, tungsten and molybdenum, aluminum, and composite materials. Finally, the article provides information on composite manufacturing methods, and tabulates the physical, and mechanical properties of electrical contact materials, including copper, silver, gold, platinum, palladium, and composites.

This article focuses on the use of noble and precious metals for biomedical applications. These include gold, platinum, palladium, ruthenium, rhodium, iridium, and osmium. The physical and mechanical properties of noble and precious metals are presented in tables. A brief discussion on the ancient history of noble and precious metal use in dentistry is provided. The article discusses the use of direct gold dental filling materials, direct silver dental filling materials, traditional amalgam alloys, high-copper amalgam alloys, and gallium alloys in biomedical applications. It also provides information on gold coatings and iridium oxide coatings for stents.

This article discusses the fundamentals of electroplating processes, including pre-electroplating and surface-preparation processes. It illustrates the four layers of a plating system, namely, top or finish coat, undercoat, strike or flash, and base material layers. The article describes various plating methods, such as pulse electroplating, electroless plating, brush plating, and jet plating. It reviews the types of electrodeposited coatings, including hard coatings and soft coatings. The article also details the materials available for electroplating, including electroplated chromium, electroplated nickel, electroless (autocatalytic) nickel, electroless nickel composite coatings, electroplated gold, and platinum group coatings. These are specifically tailored toward plated coatings for friction, lubrication, and wear technology. The article concludes with a discussion on the common issues encountered with electroplating.

This article discusses corrosion resistance of titanium and titanium alloys to different types of corrosion, including galvanic corrosion, crevice corrosion, stress-corrosion cracking (SCC), erosion-corrosion, cavitation, hot salt corrosion, accelerated crack propagation, and solid and liquid metal embrittlement. A short section discusses the addition of alloys that can improve the corrosion resistance of titanium.

This article discusses the chemical composition, fabrication characteristics, applications, mechanical properties, mass characteristics, thermal properties, electrical properties, optical properties, and chemical properties of precious metals, namely, silver, gold, platinum, and palladium and their corresponding alloys.

Titanium alloys are often used in highly corrosive environments because they are better suited than most other materials. The excellent corrosion resistance is the result of naturally occurring surface oxide films that are stable, uniform, and adherent. This article offers explanations and insights on the most common forms of corrosion observed with titanium alloys, including general corrosion, crevice corrosion, anodic pitting, hydrogen damage, stress-corrosion cracking, galvanic corrosion, corrosion fatigue, and erosion-corrosion. It also provides practical strategies for expanding the useful application range for titanium and includes a comprehensive overview of available corrosion data.

The analysis of composite materials using optical microscopy is a process that can be made easy and efficient with only a few contrast methods and preparation techniques. This article is intended to provide information that will help an investigator select the appropriate microscopy technique for the specific analysis objectives with a given composite material. The article opens with a discussion of macrophotography and microscope alignment, and then goes on to describe various illumination techniques that are useful for specific analysis requirements. These techniques include bright-field illumination, dark-field illumination, polarized-light microscopy, interference and contrast microscopy, and fluorescence microscopy. The article also provides a discussion of sample preparation materials such as dyes, etchants, and stains for the analysis of composite materials using optical microscopy.

The reflected light microscope is the most commonly used tool to study the microstructure of metals, composites, ceramics, minerals, and polymers. For the study of the microstructure of metals and alloys, light microscopy is employed in the reflected-light mode using either bright-field illumination, dark-field illumination, polarized light illumination, or differential interference contract, generally by the Nomarski technique. This article concentrates on how to reveal microstructure properly to enable the proper identification of the phases and constituents and, if needed, measuring the amount, size, and spacing of constituents, using the light optical microscope. The discussion covers the examination of microstructures using different illumination methods and includes a comparison between light optical images and scanning electron microscopy images of microstructure.

This article focuses on the recycling of metals including iron and steel, stainless steel, superalloys, nickel, aluminum, copper, precious metals, lead, magnesium, tin, titanium, and zinc. It provides information on the identification and sorting of scrap metals and discusses the equipment and procedures used for small-scale and large-scale scrapping operations.

This article provides a detailed account on forming operations (blanking, piercing, press-brake forming, contour rolling, deep drawing, cold forming, and hot forming) of various nonferrous metals, including aluminum alloys, beryllium, copper and its alloys, magnesium alloys, nickel alloys, titanium alloys, and platinum metals. It discusses the formability, equipment and tooling, and lubricants used in the forming operations of these nonferrous metals.

Brazing and soldering are done at temperatures below the solidus temperature of the base material but high enough to melt the filler metal and allow the liquid filler metal to wet the surface and spread into the joint gap by capillary action. This article discusses the common advantages of both brazing and soldering. It describes the brazing and soldering of cast irons, as well as the selection of brazing filler material. The article discusses various brazing methods: torch brazing, induction brazing, salt-bath brazing, and furnace brazing. It concludes with information on the application examples of brazing of cast iron.

This article is a compilation of color etchants that have been developed for a limited number of metals and alloys. It describes the optical methods for producing color, such as polarized light and differential interference contrast, with illustrations. The article discusses film formation and interference techniques such as anodizing, chemical etching, and tint etching. It provides a description of reagents that deposit sulfide films and molybdate films. The article concludes with a discussion on the thermal and vapor deposition methods to produce color.

Ceramic materials serve important insulative, capacitive, conductive, resistive, sensor, electrooptic, and magnetic functions in a wide variety of electrical and electronic circuitry. This article focuses on various applications of advanced ceramics in both electric power and electronics industry, namely, dielectric, piezoelectric, ferroelectric, sensing, magnetic and superconducting devices.

Metal powders are used as fuels in solid propellants, fillers in various materials, such as polymers or other binder systems, and for material substitution. They are also used in food enrichment, environmental remediation market, and magnetic, electrical, and medical application areas. This article reviews some of the diverse and emerging applications of ferrous and nonferrous powders. It also discusses the functions of copier powders and the processes used frequently for copier powder coating.