Hot-tinning of low tin bronzes

Identification of hot-tinning on corroded bronze is often a challenging task due to the various mechanisms by which shiny or grey surface finishes can be formed. The nature of intermetallic compounds formed during hot-tinning changes during use because of solid state diffusion of copper, or due to application of heat at temperatures above the melting point of tin. To identify their presence, a clear understanding of tinning microstructures must be combined with knowledge of their forms relative to corrosion structures developed from general corrosion of the underlying bronze. This study reports on the examination and identification of the intermetallic phases associated with tinning. Reported experimental work is designed to examine aspects of the formation and detection of intermetallic compounds that can be used to discuss the challenges associated with definitive identification of tinning on low-tin bronzes