What kinds of polishing abrasives are there?

1. Diamond

Abrasives have extremely high hardness, with sharp and pointed particle shapes. It has a good grinding effect on materials of different hardness and performs well in polishing alloy samples of different phases with significant differences in hardness. In addition, diamond polishing abrasives have a long grinding life and high cutting capacity, thus consuming less abrasive. At the same time, they can also prevent the formation of a deformation disturbance layer on the surface of the sample.

2. Alumina

Abrasives have a very high hardness and generally do not undergo chemical reactions with the material being polished. Alumina polishing abrasive is a commonly used polishing abrasive for general steel samples. However, it is not suitable for polishing aluminium and aluminium alloys, as aluminium oxide abrasives can easily make the aluminium surface dull and cause corrosion pits.

3. Chromium oxide

Its polishing ability is weaker than that of alumina and it can be used for polishing steel samples.

4. Iron oxide

Abrasives have achieved an extremely bright surface, but at the same time, it is prone to deformation and disruption layers, and non-metallic inclusions will be dragged out of the metal matrix of the sample. Therefore, it is rarely used.

5. Magnesium oxide

Abrasives have a relatively low hardness, extremely fine particles, a sharp shape and a good grinding edge. It is more suitable for polishing samples of aluminum, magnesium and other non-ferrous metals and alloys. It has a small traction effect on non-metallic inclusions in steel samples, and thus is particularly suitable for inclusion inspection and polishing of cast iron graphite samples, which is especially beneficial.