Re: Optical powders
Bill Marriott (btk@ix.netcom.com)
Wed, 19 Jul 1995 19:29:14 -0700
You wrote:
>
>I have acquired some Aloxite, labelled as 175 and 225 -- the 225 is
>the coarser of the two, both are finer than 320, but coarser than 800
>-- I suspect they might be equivalent to 400 and 550ish.
>
>Is anyone on here conversant with this grading system? If so, could
>you let me have the micron size of these powders. Needless to say,
>the person from whom I acquired them hasn't got a clue :-)
>
>Clear Skies,
>Steve <sft@aegis1.demon.co.uk>
>
>
Grit sizes are usually, but not consistantly , are based on how many
particles fit into an inch. In the strict sense, Optical Powders are
graded in micron size, so I suspect we're dealing with 17.5u and 22.5u
which is consistant with the fact the 175 is finner. We used to use
17.5 optical powder for sandblasting the IC's off Silicon Wafers before
reclaiming. it is much harder compound than Aluminum Oxide, but not as
hard as SiC. Should work great for mirror grinding, should be able to
follow up with 9u AO, and then time to polish...
Bill Marriott
btk@ix.netcom.com