Accelerated growth of tin whiskers

It has been shown experimentally that the growth rate of tin whiskers may be accelerated up to 10,000 times the previously observed spontaneous rate by the application of pressure up to 7,500 psi. It is shown that these whiskers may exhibit three stages of growth: 1. (1) an induction period (sometimes unobservably small); 2. (2) a period of constant growth rate, and 3. (3) an abrupt transition to a much slower growth rate. The growth rate during period (2) is directly proportional to the applied pressure. The spontaneous growth rate is shown to correspond to a free-energy dissipation of about 110 joule per gram atom of tin and the fastest accelerated rate to about 104 times this value. It is verified that tin whiskers grow from the base rather than the tip.