Indium solders.(TECH SPOTLIGHT)

Indium-base solders share the common characteristics of low melting point (Fig. 1) and extreme softness and ductility. Moreover, it remains ductile even at cryogenic temperatures. The mechanical properties are mostly a reflection of the fact that at room temperature, indium solders operate at a very high homologous temperature. That is, 25[degrees]C (77[degrees]F, 298K) is close to the melting point when expressed in Kelvins. At high homologous temperatures, the rate of solid-state diffusion in metals with simple crystal structures is sufficiently fast that microstructural changes ...