From the perspective of density
The density of silicon is approximately 2.33 g/cm³.
The density of silicon carbide (SiC) is approximately 3.21 g/cm³. The silicon carbide actually used to make galvanometer lenses is not dense. The bottom layer is honeycomb-shaped. Only the reflective surface layer is dense. Therefore, the actual density of galvanometer lenses made of silicon carbide is lower than that of silicon. It is actually lower than 2g/cm³. I have not measured the specific amount, but it is definitely lower than silicon.
The density of quartz (silica, SiO₂) is approximately 2.65 g/cm³.
From the perspective of intensity
The strength of silicon varies due to its polycrystalline structure and is generally in the range of 70-250 MPa.
Silicon carbide has higher strength and can reach the range of 300-600 MPa.
The strength of quartz is relatively high, reaching the range of 1500-1900 MPa.
From the melting point
The melting point of silicon is approximately 1,414°C (2,577°F).
The melting point of silicon carbide is approximately 2,830°C (5,130°F).
The melting point of quartz is approximately 1,690°C (3,074°F).
From the price point of view
Silicon is relatively cheap
Quartz is more expensive
Silicon carbide is very expensive
As we all know, the first requirement for galvanometers is to be fast, and the second is to be able to withstand high power (after all, not every marking machine is high-power, only the power or peak power of welding galvanometers and femtosecond and picosecond lasers Relatively high), the pursuit again is the price discount, and it is also very important not to break the galvanometer lens casually.
For most laser marking machines, the power is not very high and the main requirement is fast speed, so it is usually more suitable to choose cheap, low-density silicon as the substrate.
For some customers who are making pulse fiber marking machines of more than 100 watts or continuous fiber galvanometer welding machines of more than 1000 watts, because the power is relatively high, the galvanometer lenses are required to withstand high power. It is recommended to choose galvanometers made of quartz substrate. Lenses are more suitable. If you don’t care about the price, silicon carbide is of course better.
For some customers who are doing solar dicing, they require stable and durable processing, and at the same time they pursue speed and don’t care much about the price. It is recommended to choose galvanometer lenses made of silicon carbide base.
But for some customers who are welding large-spot galvanometers, because the galvanometer lenses have large spots, the galvanometer lenses are relatively heavy and have relatively large inertia. Silicon carbide galvanometer lenses are not strong enough and are easily broken, so it is recommended to use quartz materials.