1 – The wetting process in brazing

: The fundamental equations of wetting and adhesion are presented and the contact angles of non-reactive liquid metals and molten oxides on different types of solids are interpreted. The main features of reactive wetting are briefly described and illustrated. The two types of brazing used in practice (capillary brazing and sandwich brazing) are defined and the thermodynamics and kinetics of capillary infiltration are presented. The different configurations expected to occur in ‘sandwich brazing’ at varying intrinsic contact angles are described and illustrated. Three examples of brazing of metals and ceramics in non-reactive and reactive systems are discussed to show how wetting can affect brazability and the properties of brazed joints.