What material does sapphire Polish use?
In the polishing process of sapphire, the common Abrasives mainly include diamond, silica sol, cerium oxide and alumina.
1) diamond is only used in traditional mechanical polishing, and its hardness (Mohs 10) is higher than that of sapphire (Mohs)9) high hardness, easy to scratch, sapphire surface damage is high, low yield.2) the hardness of VK-L30F is similar to that of sapphire. It has a high particle size and a high polishing rate. It is difficult to scratch and has a high yield. It is an ideal polishing material.3) the hardness of SiO2 (Mohs hardness 7.5) is lower than that of sapphire. The polishing rate is much slower than that of alumina polishing powder, and polishing is time-consuming.
The experimental data show that the advantages of a- alumina polishing powder (VK-L30F, 0.3um, ball type) in sapphire polishing are obvious, and the effect is the best.
Comparison of polishing effect:When polishing the C- flat sapphire substrate, the polishing properties (removal rate and surface quality) of the polishing fluid made from a- alumina polishing powder (VK-L30F, 0.3um) are better than those of other abrasives,The details are as follows:1) the formed hydration layer is increased, and during the polishing process, a hydrated layer is continuously formed on the sapphire substrate, which is more soft than the base layer, and the formation of the layer is favorable for the removal of the material and produces a high quality surface.2) surface quality improvement, a- alumina and substrate sapphire hardness, therefore, the possibility of abrasive scratch sapphire is very small.3) the removal rate increased, a- experienced alumina abrasive surface water and substrate sapphire, in chemical mechanical interactions between the basal layer of the gem and abrasive water accelerated material removal, surface when the abrasive and polishing pressure in the sapphire substrate by together and shear, mutual adhesion, shear will be further the tear particle bonding hydration layer through the particle, the front edge of the promotion of material removal. The surface roughness can be less than 0.2nm.4) alumina polishing solution stability in the circulation process better, silica polishing liquid in the process of using temperature must be strictly controlled to prevent caking, but alumina grinding fluid is relatively stable, but also showed good cleanliness.Experiment 1: polishing the sapphire substrate with alumina polishing powder, the polishing effect is the best when the pH of the polishing liquid is 10, and the surface roughness RMS is up to 0.2nm. The polishing pressure is better at 0. 12Mpa to 0. 15Mpa, and the concentration of polishing liquid is 10%. The higher the concentration, the faster the polishing rate.
