2007-07-07 05:22:21 · 2 answers · asked by devilblues 1 in Science & Mathematics ➔ Chemistry
Only for initial stages of grinding. After each stage, we need to switch to a finer grit and also rotate the specimen by 90 degrees so that the scratch marks from the previous stage of polishing are removed in the next stage.
Final polishing is done on find grit paper and if needed, chemical pickling (etching) is done to reveal the microstructure correctly.
2007-07-07 05:29:59 · answer #1 · answered by Swamy 7 · 0⤊ 0⤋
As coarse grit grains can be removed from the metal surface relatively easily as compared to fine grit grains.
- It is easier to clean the surface with coarse grit paper as compared to fine grit paper .
- The polish will be more shining and smooth after use of coarse grit sand paper.
2007-07-11 01:56:39 · answer #2 · answered by sb 7 · 0⤊ 1⤋