Effect of temperature on process in precision part processing

As for the precision mechanical parts processing industry, the sufficient precision is often able to directly reflect the processing strength of its workshop. We know that temperature is a major factor affecting the processing accuracy.

The following is a small series for everyone to introduce:
In the process of intrinsic machining, under the action of various heat sources (conflict heat, cutting heat, ambient temperature, heat radiation, etc.), the temperature changes of the machine tool, the tool, the workpiece to be processed, etc. will be thermally deformed, thus affecting the workpiece and the tool. The relative displacement between the two forms a machining deviation, which in turn affects the machining accuracy of the part. For example, the linear expansion coefficient of steel is 0.000012/°C, and for steel parts with a length of 100mm, it will elongate by 1.2μm when the temperature rises by 1°C. In addition to the temperature transformation, which directly affects the expansion and contraction of the workpiece, it also affects the accuracy of the machine tool.


　　In precision machining, higher requirements are placed on the machining accuracy and accuracy of the workpiece. According to the statistics of related materials, the processing deviation caused by thermal deformation in precision machining accounts for 40%-70% of the total processing deviation. Therefore, in high-precision precision machining, in order to prevent the workpiece from expanding and contracting due to temperature change, it is usually strictly stated. The reference temperature of the environment and the deviation boundary of the temperature transition are established. The constant temperature processing of 20 °C ± 0.1 °C and 20 ± 0.01 °C still appears.

Under normal circumstances, in order to prevent the workpiece from being subjected to expansion and contraction due to temperature change during processing and metering, the constant temperature and humidity test chamber for precision machining usually strictly follows the reference temperature in the room and formulates the deviation boundary of the temperature transition. The relative humidity requirements of the air are not as strict as the accuracy of textile testing. For example, a national-level ultra-precision machining laboratory requires a temperature of 20 °C ± 0.2 °C and a relative humidity of 45% ± 5%.

In the future, with the development of society, the advancement of craftsmanship, and the temperature control technology for precision parts processing, it will become more and more developed.