This article addresses dies and die materials used for hot forging in vertical presses, hammers, and horizontal forging machines (upsetters). It reviews the properties of die materials for hot forging, including good hardenability, resistance to wear, plastic deformation, thermal fatigue, and mechanical fatigue. The article describes heat treating practices commonly employed for chromium- and tungsten-base AISI hot-work tool steels. It discusses the fabrication of impression dies, and the advantages and disadvantages of cast dies. The article concludes with a discussion on the factors that affect die life and safety precautions to be considered during die construction.

This article describes the mechanics and processing characteristics of equal-channel angular extrusion (ECAE). Tool design considerations for the ECAE are discussed. During ECAE, severe plastic strains and simple shear deformation mode contribute to strong, sometimes unusual effects of processing on structure and properties. The article explains these effects and concludes with a discussion on the applications of the ECAE.

Metalworking is one of the three major technologies used to fabricate metal products. This article tabulates the classification of metal forming processes. It discusses different types of metalworking equipment, including rolling mills, ring-rolling machines, and thread-rolling and surface-rolling machines. The article outlines the significant characteristics of pressing-type machines: load and energy characteristics, time-related characteristics, and accuracy characteristics. It summarizes different specialized processes such as advanced roll-forming methods, equal-channel angular extrusion, incremental forging, and microforming. The article describes the thermomechanical processing of nickel- and titanium-base alloys and concludes with information on the advancements in process simulation.

This article describes the melting process of casting metals used in hot chamber die casting. It discusses the design and capabilities of injection components, such as gooseneck, plunger, and cylinder. The article reviews the distinctions between hot and cold chamber processes. Gate and runner design and temperature control for die casting are discussed. The article explains the ejection and post-processing techniques used for the hot chamber die casting. The techniques include robotics operation, recycling, and fluxing.

This article begins with discussion on forgeability and the factors affecting the forgeability of aluminum and aluminum alloys. It describes the types of forging methods and equipment and reviews critical elements in the overall aluminum forging process: die materials, die design, and die manufacture. The article discusses the critical aspects of various manufacturing elements of aluminum alloy forging, including the preparation of the forging stock, preheating stock, die heating, lubrication, trimming, forming and repair, cleaning, heat treatment, and inspection. It concludes with a discussion on the forging of advanced aluminum materials and aluminum alloy precision forgings.

This article examines how design and materials selection address diverse requirements, such as cost, speed, and quality requirements of the process paired with the functional requirements of conventional die casting tooling, specifically tooling for high-volume processes. It discusses considerations, including properties of the material being cast, capacity and operating parameters of the casting machines being used, and economics of post processing that are considered along with the functional requirements.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

This article describes the extrusion process, which converts soft, plastic material into a particular form using an extruder, or screw conveyer. It discusses the two main types of plastic extruders, twin-screw and single-screw, estimation of extruder capacity, and design and operations (heating, cooling, downstream sizing, corrugating, and crossheading) of the screw, the most important component of any extruder. It discusses the shapes produced by screw extrusion and the types of extrusion products produced by extrusion processes, including blown-film extrusion, flat-film or sheet extrusion, chill-roll film extrusion, pipe or tube extrusion, wire and cable coverings, extrusion coating, and profile extrusion, and provides some discussion on multiple-screw extruders. The article describes the dimensional accuracy of extrusion products, and lists common defects that occur frequently in the extrusion process.

This article describes the control of alloy composition and impurity levels in die casting of zinc alloys based on agitation, use of foundry scrap, and melt temperature and fluxing. It reviews the process considerations for the melt processing of the zinc alloys. The process considerations include the usage of furnaces and launder system, scrap return, inclusions in zinc alloys, fluxing of zinc alloys, and galvanizing fluxes. The article discusses the materials and lubricant selection, casting and die temperature control, and trimming process used in hot chamber die casting for zinc alloys. It also reviews other casting processes for zinc alloys, such as sand casting, permanent mold casting, plaster mold casting, squeeze casting, and semisolid casting.

Vacuum high-pressure die casting uses a vacuum pump to evacuate the air and gases from the die casting die cavity and metal delivery system before and during the injection of molten metal. This article describes the conventional die casting, vacuum die casting, and high-pressure die casting processes.

Ribs and bosses are the integral functional elements or features of a forging that project outward from a web in a direction parallel to the ram stroke. This article describes the design, functions, and producibility of ribs and bosses. It relates their design to grain flow, metallurgical structure, measurement details, and design parameters, with supplementary data obtained from the examples of actual forgings.

The distinction between an unconfined web and a confined web describes the relative ease of flow of metal to flash during forging. This article describes the various types of unconfined and confined web-and-rib combinations encountered in the design of forgings. It informs that the limits suggested by forging producers and users covering minimum web thicknesses that are producible are helpful in estimating the producibility of a given web thickness in projected-forging design. The article briefly analyzes the web designs of several forgings, including designs for producing flat webs, contoured webs, and oblique webs. It provides a checklist to be reviewed by a web designer.

This article provides a discussion on ten rules for the effective production of reliable castings. The rules include good-quality melt, liquid front damage, liquid front stop, bubble damage, core blows, shrinkage damage, convection damage, segregation, residual stress, and location points.

This article reviews the history and methods of copper alloy continuous casting. The methods include vertical continuous casting and horizontal continuous casting. The article discusses the upcasting methods used in vertical continuous casting and strip casting used in horizontal continuous casting. The upcasting methods include Outokumpu upcasting method, Rautomead upwards vertical casting, and pressure upcasting. The article also describes the methods and processes of wheel casting and Ohno continuous casting.

Acoustic emission is the generation of stress waves by sudden movement in stressed materials. This article begins with a comparison of acoustic emission from most other nondestructive testing (NDT) methods, and discusses the range of applicability of acoustic emission. It describes the instrumentation principles of acoustic emission and reviews the role of acoustic emission in materials studies. The article illustrates the testing of metal-matrix composites (MMCs) using acoustic emission and the use of acoustic emission inspection in production quality control. It concludes with information on the structural test applications of acoustic emission inspection to find defects and to assess or ensure structural integrity.

A catalyst must be designed to have high activity and selectivity. The chemical process being catalyzed should have high productivity within a specified reactor volume with high reaction rates for the desired reactions and low rates for undesired reaction pathways. This article reviews the most general catalyst preparation procedures: impregnation, ion exchange, and precipitation. It explains the various categorizations of carrier materials: active carriers such as alumina, silica-alumina, zeolites, titanium oxide, and carbon in powder or particulate form; inert carriers such as silica, in powder or particulate form; and structural supports such as the monoliths upon which catalyzed carders are deposited. The article also describes catalyst powder processing techniques for tableting, beading, extrusion, spray drying and honeycombing.

This article reviews the bulk deformation processes for various aluminide and silicide intermetallic alloys with emphasis on the gamma titanium aluminide alloys. It summarizes the understanding of microstructure evolution and fracture behavior during thermomechanical processing of the gamma aluminides with particular reference to production scaleable techniques, including vacuum arc and cold-hearth melting, isothermal forging, conventional hot forging, and extrusion. The selection and design of manufacturing methods, in the context of processing-cost trade-offs for gamma titanium aluminide alloys, are also discussed.

Thermoforming is a manufacturing process in which thermoplastic sheets are heated, softened, clamped onto a mold, and made to conform to the shape of the mold or forming tool. It is ideally suited to large-volume runs of small items. This article focuses on major phases of thermoforming, namely, sheet transportation, heating, forming/cooling, and trimming, and different thermoforming techniques: basic female forming; basic male forming; matched-mold thermoforming; plug-assist thermoforming; pressure bubble plug-assist vacuum thermoforming; vacuum snapback thermoforming; air-slip thermoforming; and trapped-sheet, contact heat, and pressure thermoforming. It concludes with a discussion on machines and the economic concerns of thermoforming.

Aluminum and aluminum alloys are very suitable for extrusion and many types of profiles can be produced from easily extrudable alloys. This article lists the basic characteristics of aluminum and its alloys. It tabulates the aluminum extrusion alloys by series and lists the typical applications for 6xxx series aluminum extrusions. The article discusses three broad categories of extrusion profiles: solid profile, hollow profile, and semi hollow profile. It provides information on weldability and machinability, which are often considered in profile design and product performance. The article discusses different aluminum extrusion processes, such as the direct extrusion process and the indirect extrusion process. It schematically illustrates the plotting of flow stress and extrudability for several types of aluminum alloys. The article concludes with information on the heat treatment and precipitation hardening for alloys, such as 2xxx, 6xxx, and 7xxx.