This chapter introduces basic extrusion concepts, including types, processes, mechanics, and the principal variables and their effects on extrusion. The chapter defines the two basic types of extrusion commonly used in the aluminum extrusion industry, direct and indirect. The chapter discusses the mechanics of extrusion including plastic deformation and metal flow, plastic strain and strain rate, extrusion pressure, and extrusion force. The principal variables of extrusion, including billet material flow stress, extrusion ratio, dead-metal zone semiangle, speed of deformation, and extrusion temperature are discussed.

Tribology plays a critical role in extrusion. This chapter provides an overview of tribology in extrusions including a discussion about the friction models at various locations of the extrusion tooling/die material interfaces and a discussion about wear and lubrication in extrusion die and tooling. The chapter shows a flow diagram highlighting the significant input variables necessary for computer simulation using the fundamentals of friction and thermodynamics models. The chapter explains the influence of principal variables on temperature rise in extrusion. It describes the most common industrial methods of isothermal extrusion of aluminum alloys.

This chapter discusses how aluminum and other alloying constituents are added to prepare a furnace charge for the melting process, and how it is cast into billets of various aluminum alloys. Fundamental aspects of billet casting are covered to give an overview of the casting process. The melting practice is discussed, as well as grain refining and degassing. Charge material, grain refining, degassing, filtration of melt, casting systems, and casting variables are discussed. The chapter concludes with a discussion of casting defects.

This chapter discusses the extrusion technology of soft- and medium-strength aluminum alloys. The relative extrudability ratings of some soft- and medium-grade alloys are given. The chapter presents useful extrusion parameters and their relationships associated with day-to-day production practices in the aluminum extrusion industry. Useful parameters discussed include: extrusion runout; extrusion pressure; ram or extrusion speed control; and butt or extrusion discard thickness control. The chapter provides fundamental approaches to introducing and developing the design of experiments (DOE) for the aluminum extrusion plant to improve overall productivity. It also focuses on heat treatment of aluminum alloys.

In this chapter, process control of each operational stage is discussed, with a detailed process-control flow diagram to provide a better understanding and to create a process-control document of each operational process stage. This chapter also presents fundamental ideas of a complete process- and quality-control framework system of an aluminum extrusion plant, starting from alloy and billet making to the final heat treatment process parameters required to bring the extrusion to the final alloy and temper designation to meet product requirements.

This chapter discusses the scope of research and development in aluminum extrusion technology. Research in the key technology areas of friction, thermodynamics, and die wear are discussed. The chapter also highlights future developments in extrusion technology.

This chapter presents the following groupings of metals and alloys that are soldered together: steel and iron-base alloys, aluminum and aluminum alloys, and copper and copper alloys. It also presents the ancillary materials and process methods that assist the solder filler metal in completing the solder joint through induction heating. The chapter focuses on the selection of fluxes and the use of inert gases or even vacuum to realize an oxide-free base material surface both before and during the soldering process.

This chapter provides an overview of sintering techniques and the microstructures and properties that can be achieved in different material systems. It covers conventional furnace sintering, microwave and laser sintering, hot and hot-isostatic pressing, and spark plasma sintering. It describes the advantages and disadvantages of each method, the mechanisms involved, and the effect of sintering parameters on the density, grain size, and mechanical properties of titanium and tungsten heavy alloys, stainless steel, cemented carbides, ceramics, composites, and rare earth magnets.

The porous structure of powder-metal materials, and thus the sintering method, has a significant impact not only on the properties of PM components, but also on how they respond to surface treatments and fabrication processes such as coating and joining. This chapter explains how the microstructure of PM parts achieved by different sintering methods influences the development of galvanized coatings and the mechanisms involved in sinter bonding and various welding and brazing processes. It presents and interprets the results of several studies in which PM materials, including iron, copper, stainless steel, brass, and bronze alloys, are joined by spot welding, projection welding, and solid-state welding as well as furnace and microwave brazing. It also examines the effects of ZrSiO 4 additions on the friction and wear behaviors of PM bronze brake-lining materials.

The appendix contains detailed simulation examples through which readers learn how to format and analyze problems using the LAMMPS molecular dynamics simulator. By means of simulation, readers will determine the thermal expansion coefficient of copper, generate stress-strain plots for aluminum at different temperatures, calculate the surface energy of copper for different crystal orientations, investigate diffusion effects in BCC iron, estimate the sliding friction between graphene layers, compare the stacking fault energy of silver and aluminum, and analyze the properties and behaviors of liquids and gases. All examples employ a systematic problem-solving approach and include necessary input code.

This introduction presents an overview of the discovery of aluminum, the origins of the aluminum industry, and the evolution of the industry.

This chapter describes the process steps in the production of smelter grade aluminum, the environmental issues with aluminum production, and the importance of recycling. It also provides a discussion on the refining, or Bayer, process and the smelting, or Hall-Héroult, process.

This chapter provides an overview of the alloy and temper designations adopted for aluminum cast and wrought products. It explains the naming system and how to identify the main alloying elements and basic strengthening mechanism from any given alloy and temper designation. The chapter provides additional detail on the strengthening and softening mechanisms that allow aluminum alloys to attain a range of engineering properties. The strength of aluminum alloys can be controlled by three methods: solid-solution hardening by alloying, work hardening by plastic deformation, and precipitation hardening with appropriate alloying and heat treatment.

The manufacture of all aluminum wrought products begins with an ingot or a continuous strip solidified from the liquid state. During molten metal processing (MMP), aluminum undergoes a series of operations that are described in this chapter including melting and alloying, recycling, molten metal treatment, control of inclusions, ingot grain refinement, and direct chill (DC) or continuous casting.

This chapter describes the processes and alloys used in the casting of aluminum components, the advantages and disadvantages of the different shape-casting methods, and the major factors that influence alloy selection for shape-casting applications. An overview of the heat treatment of cast products is also included.

This chapter provides an overview of the rolling and finishing processes required to create a sheet, plate, or foil product from a direct chill (DC) cast ingot. The flow paths, equipment, and operations are described with a view to the basic evolution of the microstructure, surface characteristics, and dimensions.

Aluminum shapes, rod, bar, tubes, and wire may be produced directly as extrusions or by subsequent processing of continuous cast stock. This chapter describes the key aspects of aluminum extrusion and wire production focusing on the more common hot extrusion process and presenting the general types of aluminum extrusion alloys. An overview of free-machining alloys and products, and weldable 6xxx and 7xxx high-strength structural alloys is also provided.