Preparations

Last week, I prepared a sample for a workshop I would be attending this week.

The above was the sample that I prepared. This sample was given to me with scratches and an oxidized surface. The metal sample is placed into a plastic one inch mount which allows us to place it into one inch mounts inside the microscopes. Unlike my last sample, this one was heavily scratched and oxidized therefore I had to start with hand polishing. For hand polishing, I had to use pads and diamond powder.

The polishing cloth has an adhesive and I stuck it onto a glass sheet on the working counter. The diamond powder I started with was 3 microns. Diamond powder starts off at 9 microns, and moves its way down to 6 microns, 3 microns, 1 micron, and finally 0.25 microns. After 0.25 microns, the sample should be ready to use the vibratory polisher with the silicon based solvent.

To use the diamond powder, I poured a small amount on the cloth and then added some water. After the diamond powder dissolves, I pressed the sample face down onto the cloth and polished the sample using a circular motion.

This process takes 7-10 minutes per polish. After each polish, I had to use the Ultrasonik to remove any excess diamond powder and leftovers from the previous polishing before starting a new polish. If any of the previous polish had remained on the surface of the sample during a finer polish, it would scratch the surface, and I would have to restart the whole process. After every single polish, I would bring the sample to the microscope.

I did run into some issues while polishing the sample. After the 3 micron polish, I started the 1 micron polish. The problems started after I was using the 0.25 micron polish. While looking at the sample under the microscope, I would notice some scratches after the 0.25 micron polish. I had to return to the 3 micron polish and redo the whole process. After doing the process once more, the scratches reoccurred. After many tries, I had the idea of changing gloves I used and using completely new pads. After this attempt, my sample did not have any scratches after the 0.25 micron polish. I did not use the vibratory polisher for this sample on this day since I just wanted to get a good, clean surface for the workshop. All in all, I believe the preparation of this sample was a success. Although I did has some mistakes in the process, I found them and corrected them, and hopefully the next sample will be much easier to polish.