This article is concerned with gear tooth failures influenced by friction, lubrication, and wear, and especially those failure modes that occur in wind-turbine components. It provides a detailed discussion on wear (including adhesion, abrasion, polishing, fretting, and electrical discharge), scuffing, and Hertzian fatigue (including macropitting and micropitting). Details for obtaining high lubricant specific film thickness are presented. The article describes the selection criteria for lubricants, such as oil, grease, adhesive open gear lubricant, and solid lubricants. It discusses the applications of oil and gear lubricants and the types of standardized gear tests. The article presents some recommendations for selecting lubricants and lubricant viscosity for enclosed gear. It provides some examples of failure modes that commonly occur on gears and bearings in wind turbine gearboxes.

This article describes the secondary operations for cemented carbide parts, namely, diamond grinding, honing, electrical discharge machining, and brazing after sintering to achieve desired results, such as specified size, shape, edge condition, and surface finish.

The electrical discharge machining (EDM) process is used for machining dies because of its ability to machining difficult geometries or materials with poor machinability. This article provides a discussion on the fundamentals of electrical discharge erosion and the principles of EDM and orbital-movement EDM. It discusses various aspects of wire EDM in machining dies and provides an overview of the materials used in EDM electrodes. The article concludes with a discussion on electrochemical machining.

This article describes the characteristics of tools and dies and the causes of their failures. It discusses the failure mechanisms in tool and die materials that are important to nearly all manufacturing processes, but is primarily devoted to failures of tool steels used in cold-working and hot-working applications. It reviews problems introduced during mechanical design, materials selection, machining, heat treating, finish grinding, and tool and die operation. The brittle fracture of rehardened high-speed steels is also considered. Finally, failures due to seams or laps, unconsolidated interiors, and carbide segregation and poor carbide morphology are reviewed with illustrations.

This article discusses the various categories of nontraditional machining processes that are subdivided according to the form of energy being harnessed. These include mechanical, electrical, thermal, and chemical methods.

This article discusses the use of a shaped electrode for electrical discharge machining (EDM). It describes the operational methodology of the EDM. Topography, metallurgical and chemical effects, and surface integrity of the EDM surface are reviewed. The article provides information on the characteristics of electrodes and the process features of electrode manufacturing. Functions of the dielectric fluids and applications of the EDM are discussed. The article reviews the advancement in EDM such as no-wear EDM and computer numerically controlled vertical EDM. It analyzes the applications and process of the traveling wire EDM. Health and safety measures for the EDM process are also discussed.