In a message dated 97-08-25 05:55:43 EDT, you write:

>We are performing tests on black oxide to reduced oxide conversion .
>From theoretical point of view , the basic chemical reaction is :
>2 CuO +reducer = Cu2O .
>It mean , reduced oxide will weight 90% of black oxide :
>( 2 * ( 63.5 + 16 )) / ( 2 * 63.5 + 16 )
>What are the practical results ?

You should expect that the process will be reliable only on heavy, "black"
oxide, over about 0.5mg/square inch (yeah, here in the US, we do tend to mix
our measuring systems, think that is equivalent to about 0.1mg/square cm, in
a more logical system).

The failure mode that we have seen on oxides that are too light is the
strangest failure mode that this chemist has seen in a long lifetime in this
strange industry.  If the oxide is too light, the reduction process simply
does not happen on SOME foils, but not all.  It does not taper off, it simply
does not work, but not uniformly.   In other words, if the oxide is too
light, some foils will come through unreduced, and the lighter the oxide, the
greater the fraction that comes through unreduced.   I have seen panels,
where it is reduced on one side, but not on the other!!!
I cannot understand this failure mode.

You should expect that the peel strength will decrease somewhat.

And you should be able to put the oxided panel into dilute HCl for say 5
minutes, and still have most of the oxide remaining on the panel, unlike
un-reduced oxide.   Many people run test panels on their oxide line, and put
them through this test as a way of testing the reducer to make sure it is
functioning properly.

You may have to watch your pre-lamination baking cycle quite closely, as you
can destroy the oxide reduction, and bring it right back to where it was with
over baking.

Most people find that they must bake at around 100 C, rather than what was
previously typical of 125 C, and watch the time, even at the lower
temperature.

And good luck.

Rudy Sedlak
RD Chemical Company