2] What material does the watch cover have
Common surface materials mainly include the following:
1. Organic glass, also known as acrylic, is a type of plastic. This material has good elasticity and is not easily broken, but its hardness is extremely low and it is easy to scratch. After a period of use, it will also age and turn yellow.
2. Glass, which is also a commonly used material for watches, is an amorphous mixture of sodium silicate and silicon dioxide.
3. Coated glass. Surface coated glass is coated with a layer of corundum film on the surface of the glass by sputtering, with a coating thickness of several micrometers to tens of micrometers. The surface wear resistance and surface tension of this coated glass are very similar to those of artificial corundum, with high cost-effectiveness. However, the coating is very thin and will wear off if worn for a long time. At the same time, the mechanical properties of the entire machine are not much different from those of glass, and it is easy to break under stress. Many imitation watches use this material.
4. Artificial crystal is an artificial crystalline form of silica. This material is actually just the addition of lead oxide to the glass, rather than the theoretical artificial crystal of silicon dioxide. Adding lead oxide to glass can significantly improve its refractive index and make it look bright and translucent.
5. Coated organic glass, similar to coated glass, is coated with a layer of corundum. But few watch manufacturers use this material.
6. Artificial sapphire, sapphire crystal glass. It is an artificial aluminum oxide crystal. The manufacturing cost of this material is relatively high, and high-end watches generally use this material.