ABSTRACT
I. INTRODUCTION Metal joining by brazing and soldering is an ancient practice that has become a sophisticated modern technology after having undergone significant evolution and refinement over the years due to the contributions of modern materials science. The ultimate goal of this technology is to join parts into an assembly through metallurgical bonding.This is achieved by placing a relatively low-melting temperature alloy, or "filler metal" (FM) in the clearance (or gap) between the pieces or base materials (BM) to be joined and followed by heating of the assembly until the FM has melted and spread throughout the gap. The molten metal that filled the gap reacts with parts to be brazed and, after solidification, forms an integral solid whole. Figure 1 demonstrates graphically the essence of the brazing/soldering process. Assembly heating can be carried using various means including electromagnetic induction, Joule heating, oven, flame, etc. While joining temperatures above 723 K are arbitrarily associated with brazing rather than with soldering, these processes are essentially similar. In order to distinguish joining materials for both processes, those used at temperatures below 723 K are called solders, whereas those used at temperatures above 723 K are called brazing filler metals. In this chapter we will present some fundamentals of joining processes and how rapidly solidified (RS) FM offers advantageous processability, properties, reliability, and economics.
