[NewCandle] Nick's SEM photos of his aluminumcorrosionexperiments

[Keith Nagel]

Hey Nick,

What it makes me wonder is what sort of options does the machine
have for doing the calculation on the raw spectra. I've never
used one of these machines before and I'm sure in my fumblings
to understand it better we might all glean some useful information.
What's that matrix correction thingy?

Seperate from that are the pics themselves. What I am seeing,
if I understand this, is that corrosion begins at a pinhole
in the oxide layer. This is the anodic spot that grows and
spalls oxides as corrosion develops. The corrosion current
spreads radially from that point, and a cathodic ring
forms around the "halo" of oxide. The halo ( and ring) are pushed out as
more oxide
develops and less current can flow closer to the spot.
The cathodic area is still unclear to me. How does
that reaction occur? Can it be more remote from the anodic
spot? Or is it limited to the boundary line of the halo?

Elucidating these mechanisms with imaging will be a great
help to all of us here on the list, thanks again Nick.

K.

-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of Nick Reiter
Sent: Thursday, August 14, 2008 4:35 PM
To: New energy for the new world.
Subject: Re: [NewCandle] Nick's SEM photos of his
aluminumcorrosionexperiments


Hi Keith,

Therein is the great debate about EDS among thems as
uses it.

The old rule of thumb of most operators I know is that
less than about 1% is pretty much a toss - in the
noise, as it were.  Some elements appear to give
spectra of a little more distinction, particularly as
you go higher in energy.  Some labs say .5 or even .2%
can be realistic.  Others refuse to give credence to
anything less than 2%.

I've seen distinct peaks that the semi-quant assigns a
value of .2 or .3 %  And I've seen very tiny hard to
fish out peaks of B, N, C, F that come back having
startlingly parge values assigned to.

Honestly, I may have left O out of the quant in some
scans because its liable to be present so universally.
 I may have not been as consistent as I should in
either including it or removing it.

The iron is there in the quant box of the control
sample scan - 1.09%at.

The real pro techniques for analysis less than 1% are
atomic absorption, ICP, glow discharge mass spec, SIMS
and Auger.  I may be getting ICP in next year's
budget.

nnnnn

--- Keith Nagel <NewCandleAdmin at ipdiscover.com> wrote:

>
> >Yes, I know.  So, where's the iron coming from?
>
> There's a peak for iron in the control spectra, but
> it's not
> reflected in the mass percentage analysis? The Al
> would
> be corroded preferentially w/ respect to the Fe,
> leaving
> an Fe enriched layer.
>
> I have a related question about the control foil.
> Why is there
> no oxygen in the analysis? We know there is an oxide
> layer
> on the aluminum by virtue of it's having been
> exposed to air.
> Yet no O is present in the analysis? Are the values
> really good to .01%???
>
> K.
>
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