Tin pest is a term used in metallurgy to describe a transformation that occurs in the structure of tin when it is exposed to cold temperatures. If it drops below -13.2°C, it can form a brittle, powdery substance called tin pest instead of its usual crystalline form. The spelling of "tin pest" can be explained using the International Phonetic Alphabet, where the "tin" is pronounced as /tɪn/ and the "pest" as /pɛst/. Despite being a detrimental phenomenon, tin pest has been studied extensively in the field of materials science.
Tin pest, also known as tin disease or tin pest syndrome, is a term used to describe a destructive phenomenon that affects pure tin metal when exposed to extremely low temperatures. It refers to the transformation of tin from its normal metallic form, known as the β-form, into a brittle, nonmetallic, powdery substance called gray tin or α-form.
Under normal conditions, tin is a soft and malleable metal with a crystalline structure. However, at temperatures below 13.2 degrees Celsius (55.76 degrees Fahrenheit), the atomic structure of tin undergoes a phase change from a "diamond cubic" structure to a less ordered one. This transformation weakens the metallic bonding, causing the material to become brittle and crumble easily.
This transformation is irreversible, meaning once tin has undergone the transition into gray tin, it cannot revert back to its original form through heating or other means. The presence of impurities in tin, such as bismuth or antimony, can prevent the occurrence of tin pest by stabilizing the β-form of tin even at low temperatures.
Tin pest can pose significant challenges in various industries that utilize tin. It can lead to the degradation of tin-based products, such as electrical components, coatings, and soldering materials, causing loss of functionality and potential failure. Preventive measures against tin pest include alloying tin with small amounts of other metals or avoiding exposure to temperatures below the critical threshold.
The word "tin pest" is composed of two elements: "tin" and "pest".
1. Tin: The term "tin" originates from the Old English word "tin" or "tinne", which came from the Germanic language, specifically Old High German "zinn", Middle Dutch "tin", and Old Norse "tin". Ultimately, it can be traced back to the Latin word "stannum", which was used to refer to an alloy of silver and lead. Over time, the term "tin" began specifically referring to the chemical element with the atomic number 50, known for its silvery appearance and low melting point.
2. Pest: The word "pest" comes from the Old French word "peste", which in turn developed from the Latin word "pestis". Originally, "pestis" meant "plague" or "contagious disease".