1. Grind flat, use 320grit sandpaper for water cooling, grind for 2-3 minutes, remove the damaged layer caused by cutting, and make the sample surface flat. Use 320grit SiC sandpaper, water cooled, rotating at 240 RPM, rotating in the same direction *, pressure: 27N (6lbs) per sample, until the sample is ground flat.

Note: Removing the cutting damage layer is the basic task of polishing. If it is not removed completely, the direct consequence may be that the observed phenomenon may be false.

2. Coarse polishing, apply 9 μ M's metaDI diamond polishing paste is pre applied to the TEXMET polishing cloth with holes, using distilled water as a cooling lubricant, and polished for 10-15 minutes. Coarse polishing process: 9 μ M metaDI diamond polishing fluid+metaDI polishing lubricant, using ULTRA-PAD to polish the surface, rotating at 120 RPM, reverse rotation * *, pressure: 27N (6lbs) per sample, time 10min.

3. Final polishing, use MICROCLOTH or MASTERTEX polishing cloth, add MASTERMET silica suspension polishing solution, and polish for 10-15 minutes. Final polishing process: On the surface polished by MICROCLOTH, MASTERMET silicon dioxide polishing solution was used at a speed of 120 RPM, with reverse rotation and a pressure of 27N (6lbs) per sample for 10 minutes.

Note: During the polishing process, the sample needs to be rotated at a fixed time. Most metal alloys contain hard phases. If the direction is not rotated, the polished sample will have a black "long tail" on the hard phase, which affects the metallographic quality. The key to solving the "long tail" problem is to rotate the direction of the sample. You can rotate 90 or 180 degrees each time.