When choosing grinding beads, the first thing to determine is the specifications of the product, which mainly include two aspects: material and size.
With the development of grinding technology, the material of grinding beads has also undergone a series of processes of survival of the fittest, from the original natural pebbles to artificial glass beads, and then to the more popular and diverse ceramic beads today. The trend is to become more wear-resistant, denser, and able to withstand higher sander line speeds. In the market, the current mainstream ceramic grinding beads mainly include zirconium silicate beads, yttrium-stabilized zirconia beads, and cerium-stabilized zirconia beads. These ceramic materials have their own characteristics.
1. Zirconium silicate beads
Zirconium silicate beads, the main component of which is ZrSiO4, the beads are usually white and yellow, the density of dense zirconium silicate beads can reach 4.1g/cm3, and the Vickers hardness HV1 can reach 1000. It is usually suitable for sand of 9-12m/s. Mill line speed. Compared to zirconia beads, zirconium silicate beads have a lower material cost and are a cost-effective option under milder grinding conditions. In some traditional industries, zirconium silicate beads have an alias of "65 zirconium beads".
2. Yttrium Stabilized Zirconia Beads
Yttrium-stabilized zirconia beads are composed of ZrO2 added with 3mol% Y2O3. The role of Y2O3 is to act as a stabilizer to change the phase transition temperature range of ZrO2, thereby producing stable zirconia tetragonal phase at room temperature. The seed phase has higher toughness and hardness than the other two crystal phases of zirconia, monoclinic and cubic. The dense bead density of yttrium-stabilized zirconia reaches 6.0g/cm3, which is relatively bright white, and the Vickers hardness HV1 is about 1250. It is a ceramic grinding bead with high grinding efficiency and high wear resistance. High-quality yttrium zirconium grinding bead products can still work normally at a sand mill linear speed of 15m/s. Therefore, with the advancement and iteration of sand mill technology, it has gradually become a more commonly used grinding bead type in many industries. This kind of zirconium beads is called "95 zirconium beads" by many people in the market.
3. Cerium Stabilized Zirconia Beads
Cerium-stabilized zirconia beads use CeO2 as a stabilizer for ZrO2, which also plays a role in stabilizing the tetragonal crystal phase. The density of cerium oxide is higher, so the density of cerium-stabilized zirconia beads can reach 6.2g/cm3, which has a higher specific gravity and better grinding efficiency than yttrium-stabilized zirconia beads. However, the hardness and toughness of this ceramic material are slightly lower than that of yttrium-stabilized zirconium beads, so the wear resistance is slightly inferior. Since cerium oxide itself is not white, cerium-stabilized zirconia beads of different colors can be prepared by adjusting the ceramic formula. The common ones on the market are yellow, brown and more unique black.
