Diamond tool wear mechanism is more complex, and can be divided into macro-wear and microscopic wear. The former mechanical wear mainly the latter thermochemical wear. Shown in Figure 3, the basic laws of the macro wear early wear rapidly, normal wear very slowly. Observed through a powerful microscope, edge quality, and the worse the larger the jagged degrees, the more obvious early wear. This is because the diamond blade arc using mechanical methods polishing when, actually obtained is irregular fold line (see Figure 4) under cutting forces the units fold line pressure increases rapidly, resulting in accelerated blade wear. Another reason is that when the grinding pressure of the diamond cutting tool is too large or the grinding speed is too high, and when the temperature exceeds a critical value, the surface of the diamond tool can occur oxidation and graphitization, reduces the hardness of the surface of the diamond tool, is formed layer of hardness soften. Cutting forces, softening layer rapid wear. Thus, the level of quality of the diamond tool sharpening will seriously affect the consistency of its service life and dimensional accuracy.cutting disc
When the macro-wear in the normal wear stage, the wear of the diamond tool is very slow, proved wear more slowly in the direction of the crystalline direction, or (1,1,1) of the diamond. With the extension of the cutting time, the tool is still several tens to several hundreds of nanometers of wear, which is microscopic wear. Long-term observation, as well as with the X-ray spectrum of the X-ray diffraction analysis through a powerful microscope, micro diamond tool wear may be due to the following three:
With the continuous extension of the cutting time, cutting regional energy accumulation, the temperature is rising, and when the thermochemical reaction temperature is reached, the abrasive tools surface will form a new metamorphic layer. Metamorphic layer is mostly the intensity very poor oxide and carbide evolving, constantly disappear over the chips, and gradually form a wear surface.
Diamond crystals in the cutting force, especially under alternating pulse load continuing role, one after another C atom enough energy to escape from the lattice, resulting in crystal defects weaken the gravitational force between atoms in the lattice between the external force cut and peel off, and gradually form a lattice wear level reach a certain number of lattice level tool wear surface wear will be gradually formed.
Diamond cutting tool in the high-speed cutting nonferrous metals and alloys, in the long-term high temperature under high pressure, when the metal lattice of the diamond crystals with the workpiece reaches elements even when the distance between the atoms, causing mutual penetration between the atoms. Change the surface composition of the diamond crystals, so that the hardness and wear resistance of the diamond surface of the tool is reduced, and this phenomenon is known as the dissolution of the diamond. The degree of wear of the diamond cutting tool and wear rate depends on the the diamond atoms in the non-ferrous metal or other nonmetallic materials atom dissolution rate. Practice has proved that the diamond tool when cutting different materials, have different dissolution rate, that is the diamond cutting different workpiece materials, the wear speed and extent of the tool in the different cutting conditions are not the same, the greater the rate of dissolution, diamond tool The wear and tear on the faster.