Weldments made by the various welding processes may contain discontinuities that are characteristic of that process. This chapter discusses the different welding processes as well as the discontinuities typical of each process. It provides a detailed discussion on the methods of nondestructive inspection of weldments including visual inspection, liquid penetrant inspection, magnetic particle inspection, radiographic inspection, ultrasonic inspection, leak testing, and eddy current and electric current perturbation inspection. The chapter also describes the properties of brazing filler metals and the types of flaws exhibited by brazed joints.

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 presents an overview of families of brazing alloys that one is likely to encounter in a manufacturing environment. It discusses the metallurgical aspects of brazing and includes a survey of brazing alloy systems. A discussion of deleterious and beneficial impurities is provided with examples. The chapter also describes the application of phase diagrams to brazing.

This chapter discusses joining atmospheres that are used for brazing, along with their advantages and disadvantages. It discusses the processes, advantages, and disadvantages of chemical fluxing, self-fluxing, and fluxless brazing. Information on stop-off compounds that are considered as the antithesis of fluxes is also provided.

This chapter considers the role of materials in brazing operations and the manner in which they impact on the choice of processing conditions and their optimization. The concepts covered are metallurgical and mechanical constraints, and constraints imposed by the components and their solutions as well as service environment considerations.

Brazes for carat gold jewelry must meet or exceed the fineness/caratage of the component piece parts of the assembly in order for it to meet the national fineness/caratage standards and marking or hallmarking regulations for jewelry. This chapter concentrates on brazes for gold jewelry. It provides understanding of the metallurgy of gold jewelry alloys and includes a discussion of brazes for carat gold jewelry. The chapter also provides information on traditional gold jewelry brazes, the target properties of filler metals for carat gold jewelry and describes the characteristics of novel 22 carat gold solders.

This chapter discusses the process, principles, and modeling of the diffusion brazing system. The applications of diffusion brazing to wide-gap joining and layer manufacturing are also discussed.

This chapter discusses the processes involved in the wetting, spreading, and chemical interaction of a braze on a nonmetal. The chapter reviews the key materials and process issues relating to the joining of nonmetals using active brazing. Emphasis is placed on the differences in brazing to metals by established methods. The chapter also describes the designing process and properties of metal/nonmetal joints.

This appendix contains abbreviations and symbols related to brazing.

This appendix contains a brief list of general references related to brazing technology.

This chapter briefly reviews the history of brazing from ancient times to the early 20th century.

Brazing and soldering jointly represent one of several methods for joining solid materials. This chapter summarizes the principal characteristics of the various joining methods. It then discusses key parameters of brazing including surface energy and tension, wetting and contact angle, fluid flow, filler spreading characteristics, surface roughness of components, dissolution of parent materials, new phase formations, significance of the joint gap, and the strength of metals. The chapter also describes issues in processing aspects that must be considered when designing a joint, and the health, safety, and environmental aspects of brazing.