Prior to forging, it is often necessary to preform billet stock to achieve adequate material distribution. This chapter discusses the equipment used for such operations, including transverse rolling machines, electric upsetters, ring-rolling mills, horizontal presses, and rotary (orbital) and radial forging machines. It describes their basic operating principles as well as advantages and disadvantages.

This chapter defines near-net shape forging as the process of forging parts close to their final dimensions such that little machining or only grinding is required as a final step. It then describes the causes of dimensional variations in forging, including die deflection, press deflection, and process inconsistencies, and discusses related innovations.

This chapter discusses bulk deformation processes and how they are used to reshape metals and refine solidification structures. It begins by describing the differences between hot and cold working along with their respective advantages. It then discusses various forging methods, including open-die and closed-die forging, hot upset and roll forging, high-energy-rate forging, ring rolling, rotary swaging, radial and orbital forging, isothermal and hot-die forging, precision forging, and cold forging. The chapter also includes information on cold and hot extrusion and drawing operations.

Forged aluminum products vary widely in their production methods and applications. The forging process allows for control of microstructure and directional properties, and their fatigue and fracture resistance are superior to shape castings. This chapter presents the types, equipment, process steps, alloys, and products of aluminum forging.

Powder metallurgy (P/M) is a flexible metalworking process for the production of gears. The P/M process is capable of producing close tolerance gears with strengths to 1240 MPa at economical prices in higher volume quantities. This chapter discusses the capabilities, limitations, process advantages, forms, tolerances, design, tooling, performance, quality control, and inspection of P/M gear manufacture. In addition, it presents examples that illustrate the versatility of the P/M process for gear manufacture.

The vast majority of beryllium products are manufactured from blocks, forms, or billets of compacted powder that are machined or worked into shape. This chapter describes the metalworking processes used, including rolling, forming, forging, extrusion, drawing, and spinning. It covers the qualitative and quantitative aspects of each process and provides examples showing how they are implemented and the results that can be achieved. The chapter also discusses the issue of beryllium’s low formability and describes some of the advancements that have been made in near-net shape processing.

This chapter discusses the equipment and processes used to convert titanium billet and bar into useful shapes or more refined product forms. These secondary working operations include open-die, closed-die, hot-die and isothermal forging as well as ring rolling and extruding. The chapter describes each method in detail and how it affects the microstructure and mechanical properties of various titanium alloys. It also discusses the propensity of titanium to react with oxygen and hydrogen when heated and explains how to mitigate the effects.

This appendix is a glossary of terms and definitions associated with sheet metal forming.

Forging machines vary based on factors such as the rate at which energy is applied to the workpiece and the means by which it is controlled. Each type has distinct advantages and disadvantages, depending on lot size, workpiece complexity, dimensional tolerances, and the alloy being forged. This chapter covers the most common types of forging machines, explaining how they align with basic forging processes and corresponding force, energy, throughput, and accuracy requirements.

This appendix provides information on temper designations for strain-hardened aluminum, heat treatable aluminum alloys, and annealed aluminum products.

This chapter describes the processes involved in the fabrication of wrought and cast metal products. It discusses deformation processes including bending and forming, material removal processes such as milling, cutting, and grinding, and joining methods including welding, soldering, and brazing. It also discusses powder consolidation, rolling, drawing and extrusion, and common forging methods.

This chapter discusses the similarities and differences of forging and forming processes used in the production of wrought superalloy parts. Although forming is rarely concerned with microstructure, forging processes are often designed with microstructure in mind. Besides shaping, the objectives of forging may include grain refinement, control of second-phase morphology, controlled grain flow, and the achievement of specific microstructures and properties. The chapter explains how these objectives can be met by managing work energy via temperature and deformation control. It also discusses the forgeability of alloys, addresses problems and practical issues, and describes the forging of gas turbine disks. On the topic of forming, the chapter discusses the processes involved, the role of alloying elements, and the effect of alloy condition on formability. It addresses practical concerns such as forming speed, rolling direction, rerolling, and heat treating precipitation-hardened alloys. It presents several application examples involving carbide-hardened cobalt-base and other superalloys, and it concludes with a discussion on superplasticity and its adaptation to commercial forging and forming operations.

This chapter discusses the processes and procedures involved in tribotesting, the significance of test parameters and conditions, and practical considerations including test metrics and measurements and the interpretation of wear damage. It also describes the different types of erosion tests in use and common approaches for adhesive wear and abrasion testing.

The casting engineer contributes to a successful component design by offering expertise in molding, core making, and material characteristics and by recommending the most suitable casting process to use to meet quality and cost targets. The casting engineer's responsibilities include recommending locator positioning; advising about lugs, hooks, or holes for casting handling through all processes; determining the choice of a parting plane and pouring orientation; designing cores for accurate positioning, suitable venting, and proper cleaning; guiding decisions about wall thicknesses and junctions; making suggestions about casting design to eliminate distortion; optimizing the gating design for slag-free metal; and establishing the feeding techniques to eliminate shrink porosity. This chapter provides the guidelines for these responsibilities. In addition, the guidelines for the use of chaplets and chills in cast iron castings; guidelines for drafts, machine stock, tolerances, and contraction or shrink rule; and guidelines for pattern layouts and nesting are also covered.

This chapter describes the general characteristics of two commonly classified metalworking processes, namely hot working and cold working. Primary metalworking processes, such as the bulk deformation processes used to conduct the initial breakdown of cast ingots, are always conducted hot. Secondary processes, which are used to produce the final product shape, are conducted either hot or cold. The chapter discusses the primary objectives, principal types, advantages, and disadvantages of both primary and secondary metalworking processes. They are rolling, forging, extrusion, sheet metal forming processes, blanking and piercing, bending, stretch forming, drawing, rubber pad forming, and superplastic forming.

This chapter discusses the effect of friction and lubrication on forgings and forging operations. The discussion covers lubrication mechanisms, the use of friction laws, tooling and process parameters, and the lubrication requirements of specific materials and forging processes. The chapter also describes several test methods for evaluating lubricants and explains how to interpret associated test data.

This article presents six case studies of failures with steel forgings. The case studies covered are crankshaft underfill; tube bending; spade bit; trim tear; upset forging; and avoidance of flow through, lap, and crack. The case studies illustrate difficulties encountered in either cold forging or hot forging in terms of preforge factors and/or discontinuities generated by the forging process. Supporting topics that are discussed in the case studies include validity checks for buster and blocker design, lubrication and wear, mechanical surface phenomenon, forging process design, and forging tolerances. Wear, plastic deformation processes, and laws of friction are introduced as a group of subjects that have been considered in the case studies.

This chapter describes the equipment and processes used to form titanium alloy parts. It discusses the advantages and disadvantages of hot and cold forming, the factors that influence formability, and the effect of forming temperature and lubricants. It describes common processes, including brake forming, stretch forming, deep drawing, and spin forming as well as roll forming, drop-hammer forming, tube bulging and bending, and superplastic forming. It also discusses dimpling and joggling and the use of hot sizing to correct springback.