Granite is a commonly used material in PCB drilling and milling machines. Its high stiffness, thermal stability, and low thermal expansion coefficient make it an ideal choice for high precision and high-speed machining. The coefficient of thermal expansion of granite is an essential property when it comes to precision machining, as it determines the extent to which the material expands or contracts with changes in temperature.
The coefficient of thermal expansion (CTE) is the ratio of the change in dimension of a material to the temperature change. The CTE of granite is relatively low when compared to other materials like metals, plastics, and ceramics. The CTE of granite is typically 4.5 x 10-6/°C, which means that for every one-degree Celsius increase in temperature, the material expands by 4.5 x 10-6 units.
The low CTE of granite makes it an attractive material choice for high precision machining. When exposed to temperature changes, granite elements in PCB drilling and milling machines expand minimally. This means that the dimensional stability of the machine is maintained, resulting in high precision and accuracy in the machining processes. In addition, granite has excellent damping properties that ensure there is minimal vibration during machining, resulting in a smoother machined surface.
Granite's low CTE also makes it an excellent material for use in environmental conditions where temperature fluctuations are common. For instance, in parts of the world with seasonal temperature variations, the use of granite elements in PCB drilling and milling machines ensures that the material properties are maintained, and the machine operates with high repeatability.
In conclusion, the coefficient of thermal expansion of granite elements in PCB drilling and milling machines is 4.5 x 10-6/°C. This low coefficient results in minimal expansion/contraction of the material, high precision, and accuracy during machining, and excellent damping properties that minimize vibration. The use of granite in such machines ensures that the material properties are maintained, and the machine operates with high repeatability even in changing temperature conditions.
