The microstructural preparation of hard minerals requires correctly cutting and initial grinding of the sample; followed by rough polishing and polishing which minimizes damage. The use of polycrystalline diamond on low napped polishing pads effectively reduces the damage to the specimen; which can easily be removed by final polishing with colloidal silica.
Proper microstructural preparation requires minimizing fracturing and damage during cutting and initial grinding. The use of colloidal silica as a CMP polishing lubricant and abrasive significantly improves the surface finish for this class of materials.
SECTIONING
Diamond Wafering blade - medium grit / low concentration
MOUNTING
Castable Mounting with Epoxy or Acrylic resins
POLISHING
Abrasive/surface |
Lubricant |
Force/ sample |
Speed |
Time |
| 30 um DIAMAT diamond suspension on CERMESH Metal Mesh cloth | 5-10 lbs | 200/200 rpm |
Until plane | |
| 6 um DIAMAT diamond on TEXPAN polishing pad | SIAMAT colloidal silica | 10 lbs | 200/200 rpm |
5 minutes |
1 um DIAMAT diamond on GOLDPAD polishing pad |
SIAMAT colloidal silica |
10 lbs |
200/200 rpm |
5 minutes |
SIAMAT Colloidal silca on TEXPAN polishing pad |
|
10 lbs |
100/100 rpm |
5 minutes |
 |
Periclase, 200X (B.F.) Theraml etching at 1200 Celcius for 2 hours |