Diamond is the hardest, why can it be processed?

Diamond is the hardest material found so far. If the tool material must be hardened to the machined part, it is a necessary condition for the cutting process, so the diamond can not be machined. But if we expand our minds. Do not use solid cutting tools to process, so the problem of diamond processing may be solved.
In recent years, many special processing methods have been created in the world, such as electric spark, electron beam, ultrasonic wave and laser processing. These machining methods are not processed by solid cutting tools, so the hardness of machined parts is not limited. For example, the principle of laser drilling is to focus the high-energy laser beam on the surface of the component, and this small area produces extremely high temperature. As a result, the surface material is rapidly melted, the well is vaporized rapidly, and holes are formed on the surface of the parts.
Therefore, most materials, including diamond, can be perforated by laser. Therefore, the application of laser drilling is becoming more and more extensive. For example, the spray head used in the chemical fiber industry, the fuel nozzle of the rocket, the cemented carbide or the diamond, and the gemstone bearings in the table all have to be processed with laser to produce small holes on very hard materials.