Talk:Negative thermal expansion

Latest comment: 10 years ago by Stub Mandrel in topic Invar

Ice does not have negative expansivity. Transition from liquid water to water ice shows increase of volume, but as phase transition I do not think it qualifies. Water from 0 to 3.983 C does however increase in density as function of temperature.

Actually, ice does show NTE in its hexagonal and cubic phases at very low temperatures (below -200 °C). Spute 20:41, 2 February 2007 (UTC)Reply

rubber edit

Would a rubber band be an example of an object with NTE at commonly experienced temperatures? It shrinks when you heat it up with a heat gun. 4.242.147.224 (talk) 02:29, 22 June 2009 (UTC)Reply

Rubber is the classic example of an NTE material. Another interesting corollary of this is that if you stretch it, it heats up, and when it relaxes it cools down - try stretching a rubber band held against your top lip. Stub Mandrel (talk) 20:20, 19 November 2013 (UTC)Reply

Invar edit

Although some variants of invar show NTE, it is NOT a composite material (it is an alloy). I have therefore deleted it as an example of an NTE composite. Stub Mandrel (talk) 20:20, 19 November 2013 (UTC)Reply