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Herb Helbig
10-16-2002, 11:02 PM
From the November issue of Scientific American, p. 36:

"Metal shavings and chips from machining actually
consist of nanocrystals. They may provide a cheap,
plentiful source of the tiny crystals, which are
costly and difficult to make but can be four times
as strong as the metal in bulk form."

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Thrud
10-24-2002, 03:54 AM
Herb
I gave up on S.A. - they have really gone to the dogs lately. I now question everything I ever read there.

sch
10-24-2002, 08:33 AM
[QUOTE]Originally posted by Herb Helbig:
[B]From the November issue of Scientific American, p. 36:

"Metal shavings and chips from machining actually
consist of nanocrystals. They may provide a cheap,
plentiful source of the tiny crystals, which are
costly and difficult to make but can be four times
as strong as the metal in bulk form."

This was in Science News last month also. They attraction was that metals with extremely small crystalline domains were
fabricated with great difficulty and then
someone decided to look at chips from standard machining operations and found them
to consist of large aggregates of nanocrystals. All of a sudden nanocrystals are dirt cheap. Probably not in the category of buckyballs but a similar fortuitous discovery: made with great difficulty then found everywhere--soot to stardust. Steve

Al Messer
10-24-2002, 09:59 AM
Welcome back,Thrud!!

docsteve66
10-24-2002, 01:10 PM
Dave, my first magazine subscrition was in 1947 (plus minus a year) to S A. Loved the math columns, the experiements, the kind of "Shop work" and thebasic science. Dropped them in about 1985, they became part of the publish, sell or perish bunch that now defends junk science. Horrible thing is they and the other science magazines quote each other thus giving credibility to foolish theories.
The nano crystals may be correct, I have doubts though if the improvement in strength is less than a magnitude. Even the name "nano" raises my suspicions.

GUess I will wait six months to have "Analog" confirm or deny http://bbs.homeshopmachinist.net//smile.gif
Steve

trap
10-24-2002, 11:29 PM
hhhmmmm ....... metal chips and a little epoxy and we could call it JB Weld. Damn good stuf. My no 1 choice in fixing engine castings short of welding.