[Rhodes22-list] New Toy

Tue Mar 16 21:47:26 EST 2004

Ron,

Actually, the insoluble particles just naturally migrate to the grain
boundaries all by themselves in an attempt to minimize their surface area in
contact with the base metal alloy.  The real trick is to control the
precipitation conditions such that the particles have sufficient time to
diffuse thru the grains & grow big enough to lock the metallic grains in
place, but not grow so big that they start coallescing & leave some grains
not locked together.

It's pretty cool technology.

Roger Pihlaja
S/V Dynamic Equilibrium

----- Original Message -----
From: "Ronald Lipton" <rlipton at earthlink.net>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Tuesday, March 16, 2004 10:28 AM
Subject: Re: [Rhodes22-list] New Toy

> Roger,
>
>    Sounds like an interesting material.  Getting the ceramic precipitate
> to nucleate along the grain boundries sounds like quite a trick.  It
> would be interesting to see a SEM picture of the material.
>
> Ron
> ----- Original Message -----
> From: "Roger Pihlaja" <cen09402 at centurytel.net>
> To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> Sent: Tuesday, March 16, 2004 6:41 AM
> Subject: Re: [Rhodes22-list] New Toy
>
>
> > Gentlemen,
> >
> > This is college, not the public high school.  Pocket knives are common
on
> > the SVSU campus.  But, I also wasn't stuupid about it & go around
showing
> > off the knife to everyone.  Dr. Schilling, my research project advisor &
> > several other mechanical engineering students were with me in the SVSU
> > Materials Lab.  The other students were already in the lab, testing
other
> > samples, when Dr. Schilling & I started doing our cutting tests.
> Naturally,
> > the knife generated a lot of interest.  Everyone was impressed with the
> > performance.  When the tests were over, I folded the knife up & put in
my
> > backpack for the rest of the day.  No, I don't think the school
> > administration knew about it; but, I don't think it would have been a
> > problem either.
> >
> > Roger Pihlaja
> > S/V Dynamic Equilibrium
> >
> > ----- Original Message -----
> > From: "kroposki" <kroposki at innova.net>
> > To: "'The Rhodes 22 mail list'" <rhodes22-list at rhodes22.org>
> > Sent: Tuesday, March 16, 2004 7:14 AM
> > Subject: RE: [Rhodes22-list] New Toy
> >
> >
> > >
> > >
> > > Bob,
> > >
> > > Especially a sharp knife.  I wonder if he school authorities did
> > > not miss this.  Small wonder Roger is still working on his degree.
> > >
> > > Roger,
> > >
> > > How come you did not first get a distributorship on these?  It
> > > has been a long time since I had a really good pocket knife.  Makes me
> > > think about one that works.
> > >
> > > Ed K
> > >
> > > -----Original Message-----
> > > From: rhodes22-list-bounces at rhodes22.org
> > > [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Bob Keller
> > > Sent: Monday, March 15, 2004 11:38 PM
> > > To: rhodes22-list at rhodes22.org
> > > Subject: RE: [Rhodes22-list] New Toy
> > >
> > > Roger,
> > > In Georgia you would have been expelled for taking a knife to
school...
> > > Bob K
> > >
> > >
> > > >From: "Roger Pihlaja" <cen09402 at centurytel.net>
> > > >Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
> > > >To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> > > >Subject: [Rhodes22-list] New Toy
> > > >Date: Mon, 15 Mar 2004 21:02:10 -0500
> > > >
> > > >Hi Everybody,
> > > >
> > > >Well, I'm ready for a new topic.  I just received a new toy today
that
> > > is
> > > >totally cool.  The March, 2004, Volume 30, Number 5 & 6 double issue
of
> > >
> > > >"Practical Sailor" magazine ran a comparison test on sailor's rigging
> > > >knives.  They rated the Spyderco SALT 1 as a best buy.  The thing
about
> > >
> > > >this knife that caught my eye was the description of the H1
> > > precipitation
> > > >hardened stainless steel in the blade.  In my ME250, Engineering
> > > Materials,
> > > >class last semester, we learned about precipitation hardening of
> > > aluminum
> > > >alloys.  Precipitation hardening is how the really strong, hard, yet
> > > >ductile aircraft aluminum alloys like Al 7075-T6 are made.  I had
never
> > >
> > > >heard of anything analogous in a stainless steel alloy and I was
> > > curious.
> > > >
> > > >So, I went & looked up the properties of H1 stainless steel in the
> > > >metallurgical literature at the SVSU library.  The H1 alloy is
produced
> > > by
> > > >the Myodo Foundry in Japan and it appears to be a real materials
> > > >breakthrough.  Normally, with knife blade materials, there is a
> > > tradeoff
> > > >between the hardness & ability to keep a sharp edge of high carbon
tool
> > >
> > > >steels and the corrosion resistance and nonmagnetic properties of the
> > > 300
> > > >series stainless steels.  Up until now, it was impossible to have
both
> > > >corrosion resistance and a really sharp blade in the same alloy.  The
> > > H1
> > > >alloy works differently.  Precipitation hardening refers to the
> > > formation
> > > >of precipitates or particles of ceramic intermetallic ferric nitride
> > > and
> > > >chromium nitride compounds.  These intermetallic compounds are
soluble
> > > in
> > > >the base alloy composition above a certain critical temperature,
> > > allowing
> > > >the metal to be hot-worked into the shape of the blade.  As the metal
> > > is
> > > >cooled according to a proprietary heat treatment schedule, the
> > > >intermetallic compounds become insoluble, drop out of solution, &
> > > nucleate
> > > >into tiny particles.  For reasons I won't get into, these particles
> > > tend to
> > > >preferentially nucleate & grow along grain boundaries in the metal.
> > > The
> > > >presence of these particles distorts the face centered cubic (FCC)
> > > crystal
> > > >lattice structure of the base alloy & tends to lock adjacent metallic
> > > >grains together.  Think of the particles as being sort of like the
key
> > > that
> > > >fits into the keyway that locks a pulley onto a shaft.  Having the
> > > grain
> > > >boundaries of the metal locked together makes the metal much more
> > > resistant
> > > >to deformation and yielding.  (i.e. it is much harder)  But, it has
not
> > >
> > > >been work hardened or tempered like heat treated high carbon steel
> > > blades
> > > >must be.  The H1 alloy has a low carbon content and the base alloy
> > > grains
> > > >have an overall austenitic microstructure. (i.e. nonmagnetic and
> > > corrosion
> > > >resistant like 300 series stainless steel)  The H1 alloy has a
hardness
> > > and
> > > >yield strength comparable to a high carbon tool steel while
maintaining
> > > the
> > > >overall corrosion resistance, ductility, ultimate elongation, and
> > > >nonmagnetic properties of a 300 series stainless steel.  As I said,
the
> > > H1
> > > >alloy appears to be a genuine materials breakthrough!
> > > >
> > > >Naturally, I had to have one!  I ordered the knife on-line from The
> > > Knife
> > > >Center:
> > > >
> > > >www.knifecenter.com
> > > >
> > > >SP88SBK Spyderco SALT H1 Stainless 3" Serrated Blade Black Zytel
> > > Handle:
> > > >$49.95 + S&H
> > > >
> > > >The Salt 1 is available with either a plain or a serrated edge blade.
> > > I
> > > >choose the serrated edge because it was recommended by Practical
Sailor
> > > for
> > > >quick 1-pass cutting of tough lines.  Note: By the standards of high
> > > end
> > > >blades, $50 is not a particularly expensive knife.
> > > >
> > > >Anyway, my new toy arrived via UPS over the weekend & I took it to
> > > school
> > > >today.  In the materials lab, we did some cutting experiments on
tough,
> > >
> > > >exotic materials like Kevlar, Spectra, and Carbon Fiber.  With the
> > > factory
> > > >supplied edge, my new Salt 1 is so sharp, it's almost scary!  It cut
> > > thru
> > > >several layers of stacked woven prepreg cloth like butter & these
were
> > > >materials that are a lot of work to cut a single layer with a good
pair
> > > of
> > > >scissors.  Under the microscope at 100X magnification, there was no
> > > >detectable wear on the edge before vs. after cutting these materials.
> > > The
> > > >hardness of the blade checks out at >75 on the Rockwell C scale!  The
> > > edge
> > > >is sharpenable on a good Arkansas stone with cutting oil, although
with
> > >
> > > >quite a bit more effort than I am used to with even high carbon tool
> > > steel
> > > >blades.
> > > >
> > > >The Salt 1 rigging knife is a folding, locking design.  It has a belt
> > > clip
> > > >& is deployable with either hand.  Note that the H1 alloy is also
> > > available
> > > >in fixed blade versions with a sheath.  I'm strongly considering
> > > getting a
> > > >fillet knife and a hunting knife.  If you have anyone on your gift
list
> > >
> > > >that uses & appreciates really good cutting tools, they will
absolutely
> > >
> > > >love something like this!  It will instantly become their favorite
> > > knife.
> > > >
> > > >Roger Pihlaja
> > > >S/V Dynamic Equilibrium
> > > >__________________________________________________
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> > >
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> >
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