Learn something new every day - Tin Pest - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2014, 01:57:09 am
content: 'Tin Pest' - the transformation of beta tin into alpha modification (grey tin).http://www.periodictable.ru/050Sn/Sn_en.htmlThis what happens to white tin under 13.2°C. The ductile white tin transforms into another allotrope, the brittle and bulkier gray tin.How did I get to be 58 years old and never heard of this before?How many others hadn't heard of it?Apparently all the people responsible for the ROHS legislation that resulted in pure Tin being used in electronics.I knew about Tin Whiskers growth, but not this. So, any components containing pure Tin are pretty much junk below 13.2°C, is that right? As well as highly unreliable after some number of years due to conductive whisker growth.Also google: Robert Scott's Antarctic expedition tin pest

author: sleemanj
author_rank: Super Contributor
timestamp: March 17, 2014, 02:15:16 am
content: Quote from: TerraHertz on March 17, 2014, 01:57:09 amWhere do you get that? The video is at -40°C"Machined piece at -40°C. 1 second of video correspond 1 hour of real time, 20 frames per hour. Grid size - 1 cm."

author: BravoV
author_rank: Super Contributor
timestamp: March 17, 2014, 02:20:45 am
content: Quote from: TerraHertz on March 17, 2014, 01:57:09 amNot many I believe, but I did, remembered I was amazed by the story when I was a kid reading a science facts book about the tin buttons that were used at clothing that disintegrated into dust in freezing cold.Source ->http://en.wikipedia.org/wiki/Tin_pest

author: JoeO
author_rank: Frequent Contributor
timestamp: March 17, 2014, 03:01:40 am
content: Quote from: sleemanj on March 17, 2014, 02:15:16 am-40C is -40F

author: mariush
author_rank: Super Contributor
timestamp: March 17, 2014, 03:09:18 am
content: I knew about it. It was in aQIepisode some time ago and they were saying something about wagons with aluminum going through cold Russia (or another European country, maybe Germany) and arriving at destination with the wagons/cargo destroyed.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2014, 05:12:33 am
content: Quote from: sleemanj on March 17, 2014, 02:15:16 amThe 13.2 deg C came from some site I was reading. Didn't check it then, but now I did:http://en.wikipedia.org/wiki/TinQuoteI guess the very low temp for the video was to make the process go faster. Counter-intuitive as that may seem.Edit. Huh. The Greek letters in the quote died. Oh well, see the source.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: March 17, 2014, 06:43:39 am
content: As a chemist I thoroughly enjoyed this. It seems as if tin is a proto-metalloid (my own term) in that it's metallic in one allotrope and non-metalic in the other. This region of the periodic table is where all the word fun stuff happens. Much of it due to the weird orbital transitions that arise (gold is yellow, mercury is a liquid are two prime examples).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 17, 2014, 06:55:37 am
content: Now now, let's not forget plutonium, the metallurgist's dream. Pure, it goes through five phase transitions before melting!Tim

author: daqq
author_rank: Super Contributor
timestamp: March 17, 2014, 07:24:20 am
content: I knew about this, but I haven't seen a video! Thanks!Another fun thing to watch is how mercury likes alluminum: