Rapid growth of tin whiskers on the surface of Sn–6.6Lu alloy

During the storage of a Sn–6.6Lu alloy in air for several days, large amounts of thread-like tin whiskers appear on the oxidized surface of Lu4Sn5 precipitates in this alloy. Storage at 150 °C for 30 min causes hillock-type whiskers to form. The driving force for whisker growth in this Sn–6.6Lu alloy is the compressive stress resulting from the diffusion of oxygen into the lattice of the Lu4Sn5 precipitates.