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Negative CTE material

Posted by Hemos on from the making-things-work dept.

florescent_beige writes "An article on Yahoo talks about zirconium tungstate (ZrW2O8), a material that has a negative coefficient of thermal expansion over a wide range of temperatures. Being non-toxic, it has applications in dentistry, as well as metallurgy and optics. Johns Hopkins physicyst Collin Broholm describes the physics behind the behaviour."

4 of 23 comments (clear)

  1. Dumb Example... by Big+Sean+O · · Score: 3, Interesting

    You're right mostly. Humidity does effect wood more. I don't think wooden doors stick in the desert.

    A better example would be running hot water over stuck jar lid. The metal expands faster than the glass.

    Kinda off-topic but not really: Water gets denser as it cools to 4 degrees C, then it expands as the temperature drops until ice forms at 0 degrees C. Ice is acutally less dense than water (which is why it floats).

    --
    My father is a blogger.
  2. error in article. by nickbrown · · Score: 2, Interesting

    You need to change the second link in the article to include the shrink tag.
    Thus;
    http://www.jhu.edu/~jhumag/0299web/tech.html#shrin king

  3. Old News by GMontag451 · · Score: 3, Interesting

    So what? Good old water has a negative CTE, at least from 0 C to 4 C.

  4. Hot/Cold by ktulus+cry · · Score: 2, Interesting

    Alright, so now plates will explode when they go from hot to cold instead, and fillings will crack when you eat ice cream instead of drinking coffee. Does zirconium tungstate also expand/contract LESS during a temperature change? The article on Yahoo failed to mention it's response to decrease in temperature. Also - a VERY common of use of heat-shrinking material - heat-shrink tubing, its used in electrical work very frequently. Some of that stuff shrinks to a quarter of its original diameter or less.