测量机常用资料(国外英文资料).doc

测量机常用材料(国外英文资料) Common materials for measuring machine The requirements for the materials are: 1. The thermal conductivity is better, in order to avoid the outside world has a temperature change, change with time and space form of component temperature gradient, due to structure deformation of the machine (mainly torsion and bending); The thermal expansion coefficient is small, lest temperature change cause excessive elongation. To have a large amount of elastic modulus (rigidity) to avoid large deformation after force. High hardness and abrasion resistance, ensuring that it is not easily scratched and worn. The higher strength does not break; The material requirements of the moving parts are small in order to reduce the inertia force of the measuring machine due to the high speed and high speed of the measuring machine. Considering the small amount of water absorption, in case the moisture is deformed (and the quality of the granite, because of the absorption of water, is sufficient to cause the deformation of the microns); The technology is good and easy to process. The cost is low. Cast iron (mainly grey cast iron) Grey cast iron refers to cast iron with flake graphite, which has a high carbon content (2.7 ~ 4.0%), which is dark gray when broken, and is called grey cast iron. The ingredients are iron, carbon, silicon, manganese, sulfur, phosphorus, the most widely used cast iron, which accounts for more than 80% of cast iron production. Grey cast iron is a common kind of material used in the application of base, pillar, support and bed. It has the advantage of small deformation, good wear resistance, easy processing, low cost, linear expansion coefficient of parts (steel) with the most close, three coordinate measuring machine is an early use of materials. But there are also disadvantages: they are susceptible to corrosion and wear less abrasive than granite and not very strong. Present grey cast iron is mainly used in measuring machine, such as the line of line