Titanium aluminides are lightweight materials that have relatively high melting points and good high-temperature strength. They also tend to be stronger and lighter than conventional titanium alloys, but considerably less ductile. This chapter begins with a review of the titanium-aluminum phase diagram, focusing on the properties, compositions, and microstructures of alpha-2 Ti3Al alloys. It then describes the properties, microstructures, and compositions of orthorhombic, gamma, and near-gamma alloys as well as the processing methods and procedures normally used in their production.

This chapter describes the processes involved in alloy production, including melting, casting, solidification, and fabrication. It discusses the effects of alloying on solidification, the formation of solidification structures, supercooling, nucleation, and grain growth. It describes the design and operation of melting furnaces as well as melting practices and the role of fluxing. It also discusses casting methods, nonferrous casting alloys, and atomization processes used to make metal powders.

This chapter describes the basic steps in the production of titanium ingots and their subsequent conversion to standards product forms. It explains how titanium ore is reduced to a spongy residue, then granularized, compacted, and melted (along with alloying additions) to form an ingot, which may be remelted several times to achieve the necessary properties. It also discusses the cause of defects and ingot imperfections and the benefits of billet reduction and grain-refinement processes.

Brazing and soldering processes use a molten filler metal to wet the mating surfaces of a joint, with or without the aid of a fluxing agent, leading to the formation of a metallurgical bond between the filler and the respective components. This chapter discusses the characteristics, advantages, and disadvantages of brazing and soldering. The first part focuses on the fundamentals of the brazing process and provides information on filler metals and specific brazing methods. The soldering portion of the chapters provides information on solder alloys used, selection criteria for base metal, the processes involved in precleaning and surface preparation, types of fluxes used, solder joint design, and solder heating methods.

This chapter discusses the melting and conversion of superalloys and the solidification challenges they present. Superalloys have high solute content which can lead to untreatable defects if they solidify too slowly. These defects, called freckles, are highly detrimental to fatigue life. The chapter explains how and why freckles form as well as how they can be prevented. It describes the criteria for selecting the proper melting method for specific alloys based on melt segregation and chemistry requirements. It compares standard processes, including electric arc furnace/argon oxygen decarburization melting, vacuum induction melting, vacuum arc remelting, and electroslag remelting. It also addresses related issues such as consumable remelt quality, control anomalies, melt pool characteristics, and melt-related defects, and includes a section that discusses the processes involved in converting cast ingots into mill products.

Casting is the most economical processing route for producing titanium parts, and unlike most metals, the properties of cast titanium are on par with those of wrought. This chapter covers titanium melting and casting practices -- including vacuum arc remelting, consumable electrode arc melting, electron beam hearth melting, rammed graphite mold casting, sand casting, investment casting, hot isostatic pressing, weld repair, and heat treatment -- along with related equipment, process challenges, and achievable properties and microstructures. It also explains how titanium parts are produced from powders and how the different methods compare with each other and with conventional production techniques. The methods covered include powder injection molding, spray forming, additive manufacturing, blended elemental processing, and rapid solidification.

This chapter deals with the mechanics and tribology associated with the extrusion of bars, sections, and tubes. It covers direct and indirect extrusion processes in detail and demonstrates the use of important equations, relationships, and measurements for determining pressure, force, material flow, friction, die wear, heat generation, and lubrication requirements. The chapter also provides information on hydrostatic, friction-assisted, and severe plastic deformation extrusion processes, discusses the cause of instabilities and defects, and explains how to select and apply lubricants to minimize friction and die wear when extruding steel, aluminum, copper, and refractory metals.

Beryllium has been successfully joined by fusion welding, brazing, solid-state bonding, and soldering. This chapter describes these processes in detail along with their advantages and disadvantages. It also addresses application considerations such as surface preparation, joint design, and testing.

This chapter discusses coating technologies that are applicable to beryllium, including physical and chemical vapor deposition, thermal evaporation, electroplating, sputtering, ion plating, and plasma arc spraying. It describes the advantages and disadvantages of each method and the effect of temperature, pressure, and other process variables on the microstructures and properties developed.

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.

Steel is broadly classified as plain-carbon steels, low-alloy steels, and high-alloy steels. This chapter begins by describing microconstituents of low- and medium-carbon steel, including bainite and martensite. This is followed by a section discussing the effect of alloying elements on steel. Then, it provides an overview of steel casting applications. Next, the chapter reviews engineering guidelines for steel castings and feeder design. The following section provides information on feeding aids. Further, the chapter describes the elements of gating systems for steel castings. It also describes the alloys, properties, applications, and engineering details of steel. Finally, the chapter explains defects in steel castings and presents guidelines for problem solving with examples.