The primary purpose of this article is to describe general root causes of failure that are associated with wrought metals and metalworking. This includes a brief review of the discontinuities or imperfections that may be common sources of failure-inducing defects in the bulk working of wrought products. The article addresses the types of flaws or defects that can be introduced during the steel forging process itself, including defects originating in the ingot-casting process. Defects found in nonferrous forgings—titanium, aluminum, and copper and copper alloys—also are covered.

This article discusses failure mechanisms in tool and die materials that are very important to nearly all manufacturing processes. It is primarily devoted to failures of tool steels used in cold working and hot working applications. The processes involved in the analysis of tool and die failures are also covered. In addition, the article focuses on a number of factors that are responsible for tool and die failures, including mechanical design, grade selection, steel quality, machining processes, heat treatment operation, and tool and die setup.

This datasheet provides information on composition limits, processing effects on physical and mechanical properties, and fabrication characteristics of electrical bus conductor aluminum alloys 6101 and 6201 along with standard temper designations. Machining and forming characteristics of alloy 6101 are compared with related alloys and tempers.

Work or strain hardening is a natural consequence of most working and forming operations on aluminum and its alloys. This article describes the annealing practices of strain-hardened alloys. It lists the temper designations for strain-hardened alloys. The article discusses the annealing of worked structures in terms of recovery, recrystallization, and grain coarsening. It summarizes some of the annealing treatments used in conjunction with fabrication by metal working, including preheating, interannealing, self-annealing, stabilization, and stoving. The article concludes with information on the key process parameters affecting the final properties of aluminum alloys.

Aluminum and its alloys are among the more formable materials of commonly fabricated metals. This article discusses the formability, bendability, and springback of aluminum and its alloys. It describes the forming limit diagrams that illustrate the biaxial combinations of strain that can occur without splitting. The article reviews various bending methods, such as draw, compression, ram and press, roll, and stretch or tension bending. It describes the process variations of incremental sheet forming (ISF), such as single-point incremental forming, two-point incremental forming, and kinematic incremental sheet forming. The article concludes with a discussion on spinning, warm forming, and superplastic forming.

This article introduces the basic characteristics, processes, and product forms associated with the five major categories of aluminum wrought products, namely, flat-rolled products (sheet, plate, and foil); rod, bar, and wire; tubular products; profiles; and forgings. It summarizes the various product forms in which commonly used wrought aluminum alloys are available. The article also provides design guidelines for aluminum extrusions and discusses various forming methods.

This article describes friction force as a function of normal force in dry forming. It focuses on metal forming operations usually classified as cold working and hot working based on metallurgical considerations. The article discusses surface flattening and roughening of workpiece asperities in metal forming. It presents advanced tribology models and results for friction in isothermal forging operations in which the tooling is maintained at a temperature close to that of the workpiece. The article provides information on heat transfer models. It discusses the effect of wear in manufacturing processes. The article concludes with information on the main categories of tool and die materials used for a variety of manufacturing application.

Current understanding of polishing wear involves a combination of abrasive, plastic flow, and tribochemical wear. This article explains these mechanisms and the correlation between them. Some explanations about practical polishing wear control, applications, and future prospects are also given. This article discusses the influence of size and number of wear particles on polishing at three abrasive wear modes. These include cutting, wedge forming, and plowing. The article concludes with information on applications and prospects of polishing wear control.

This article begins by describing the designations of cast and wrought aluminum alloys. It explains the effects of main alloying elements in aluminum alloys: boron, chromium, copper, iron, lithium, magnesium, manganese, nickel, phosphorus, silicon, sodium, strontium, titanium, and zinc. The article describes the microstructure of cast and wrought aluminum alloys and the various strengthening mechanisms, including solid solution, grain refinement, strain or work hardening, precipitation (or age) hardening, and dispersoid strengthening. The article explicates the tribological behavior of aluminum alloys, aluminum-base composites, and metal-matrix composites. It presents the effect of material-related parameters and external factors on wear behavior and transitions of aluminum-silicon alloys. The article also presents the most important factors affecting the dry sliding wear behavior of particle-reinforced aluminum-base composites against a steel counterface.

This article focuses on environmental and application factors in solid friction. It covers the tribology of contact between a soft and hard material, including mechanisms and testing. The article describes the tribology of contact between a metal and tool during metalworking processes. It also discusses the tribology of metal friction at elevated temperatures.

The most widely accepted alloy and temper designation system for aluminum and its alloys is maintained by the Aluminum Association and recognized by the American National Standards Institute (ANSI) as the American National Standard Alloy and Temper Designation Systems for Aluminum (ANSI H35.1). This article provides a detailed discussion on the alloy and temper designation system for aluminum and its alloys. The Aluminum Association alloy designations are grouped as wrought and cast alloys. Lengthy tables provide information on alloying elements in wrought aluminum and aluminum alloys; nominal composition of aluminum alloy castings; typical mechanical properties of wrought and cast aluminum alloys in various temper conditions; and cross references to former and current cast aluminum alloy designations.

This article provides an in-depth treatment on the deformation and recrystallization of titanium alloys. It provides information on the predominant mode of plastic deformation that occurs in titanium in terms of the most common crystallographic planes. The article explains the relationship of the recovery process to the recrystallization, grain-growth process, and the effects of time and temperature on stress relief. It describes the factors that influence the rate of recrystallization and the conditions required for neocrystallization to occur. The article explains the mechanism of strain hardening and its effects on the mechanical properties of titanium alloys. It also discusses the factors that influence the superplasticity of titanium alloys.

This article provides information on the Unified Numbering System designations and temper designations of copper and copper alloys. It discusses the basic types of heat treating processes of copper and copper alloys, namely, homogenizing, annealing, and stress relieving, and hardening treatments such as precipitation hardening, spinodal hardening, order hardening, and quench hardening and tempering. The article presents tables that list the compositions and mechanical properties of copper alloys. It also discusses two strengthening mechanisms of copper alloys, solid-solution strengthening and work hardening. Finally, the article provides information on the equipment used for the heat treating of copper and copper alloys, including batch-type atmosphere furnaces, continuous atmosphere furnaces, and salt baths.

Annealing is an essential treatment in the fabrication of metal parts and semiproducts. This article discusses the processes involved in annealing, namely, recovery, recrystallization, and grain coarsening. It lists the heat treatment conditions of processed aluminum alloys. It provides information on the types of heat treatment, which include preheating, full anneal, stabilization, and stoving. The article describes the steps involved for achieving the age-hardening effect and the strongest hardening effect in aluminum. The steps to increase the strength of aluminum alloys by extremely fine, dispersed second-phase particles are: solution heat treatment, quenching, and age hardening. Finally, the article also discusses the process parameters of annealing, including the effect of strain, effect of temperature, effect of heating rate, and the effect of alloy elements, and the effect of annealing on anisotropy.

This article provides a detailed discussion on heat treatment of titanium alloys such as alpha alloys, alpha-beta alloys, and beta and near-beta alloys. Common processes include stress-relief, annealing, solution treating, aging, quenching, and age hardening. It provides information on the effects of alloying elements on alpha/beta transformation. The article also discusses the heat treating procedures, and the furnaces used for heat treating titanium and titanium alloys.

Monotectic alloys can be classified based on the difference between the critical temperature and the monotectic temperature. This article begins with a schematic illustration of monotectic reaction in copper-lead system. It discusses the solidification structures of monotectics and illustrates the monotectic solidification for low-dome alloys. The forming mechanism of the banded structure of copper-lead alloy in upward directional solidification is also described.

Successful application of forging and hot pressing involves careful consideration of powder preparation and forming process parameters. This article describes the important process features for powder forging and hot pressing, along with specific applications and materials used.

Hardenable steels with high-alloy content includes a family of nickel-cobalt steels with high strength and high toughness. This article describes various heat treatments, namely, normalizing, annealing, hardening, tempering, stress relieving, overaging, quenching, refrigeration, and straightening treatment, applied to HP9-4-20, HP9-4-25, HP9-4-30, and HP9-4-45 steels. These steels have high fracture toughness when heat treated to very high strength levels. The article also describes heat treatments applied to other alloys such as AF 1410, AerMet 100, AerMet 310, and AerMet 340, which provide a good combination of high strength and toughness that make them attractive for aerospace application. It also presents tables that provide information on the effect of aging temperatures and heat treatment on mechanical properties and impact energy of these steels.

This article describes the effects of furnace atmospheric elements, including air, water vapor, molecular nitrogen, carbon dioxide, and carbon monoxide, on steels. It provides useful information on six groups of commercially important prepared atmospheres classified by the American Gas Association on the basis of the method of preparation or on the original constituents employed. These groups are designated and defined as follows: Class 100, exothermic base; Class 200, prepared nitrogen base; Class 300, endothermic base; Class 400, charcoal base; Class 500, exothermic-endothermic base; and Class 600, ammonia base. These are subclassified and numerically designated to indicate variations in the method by which they are prepared. The article also contains a table that lists significant furnace atmospheres and typical applications.

The warm and hot working of metals provide the ability to shape important materials into component shapes that are useful in a variety of applications requiring strength, toughness, and ductility. This article focuses on a variety of metals that can be hot or warm worked, and describes the characteristics and processing considerations of each metal. It discusses forging because it is a versatile metalworking process and performed at cold, warm, and hot working temperatures. The article also presents the applications of steels, stainless steels, aluminum alloys, titanium alloys, superalloys, and copper alloys.