Orientation Methods of Diamond Cutter

Ultra-precision cutting is an important field in ultra precision machining, which is a new technology with broad content. Using precision single crystal diamond cutter to machine nonferrous metal and nonmetal, can directly obtain the smooth processing surface, which can take the place of the ultra precision grinding and finishing process, greatly improve the machining efficiency, and also can guarantee the machining precision and surface quality. In recent years, the single crystal diamond cutter has already deeply entered every field of mechanical processing, which is playing a more and more important role.

At present, the main crystal orientation methods are divided into three: Artificial visual inspection crystal orientation, laser crystal orientation and X-ray crystal orientation.

A. Artificial visual inspection crystal orientation

Artificial visual inspection is based on the external geometric shapes, surface growth, corrosion characteristics and the geometry relationship between the crystal plane of natural crystal, adding the long-term working experience of operators, which is a kind of rough crystal orientation through the observation and experiment. This method is simple and easy. It does not need to use equipments, but the directional accuracy is poor, and the experience demand for operators is high. What’s more, if the processed cutter loses the natural characteristics of single crystal, it is unable to undertake artificial visual inspection orientation.

B. Laser crystal orientation

Laser crystal orientation is to use the laser with good coherence beating down on the surface of diamond crystal. In different crystallization direction, crystal face and microscopic pits formed on the surface in the process of growth, are reflected on the screen, forming the diffraction light images. But in fact, because of interference factors, the crystal face and microscopic pits formed naturally are often not obvious or cannot be observed. Therefore, the crystal needs to pass through appropriate artificial corrosion before orientation, to form the characteristic appearance.

C. X-ray crystal orientation

Diamond symmetrical type is 3L44L36L29PC. To use X-ray irradiate diamond, rotate diamond fixture, make the fourth, third or second symmetric axis and the direction of the X-ray beam overlap, it will show the symmetrical diffraction image.

As a result of the X-ray wavelength close to the crystal lattice constant, the diffraction happens when the x-ray goes through the crystal or is reflected from the crystal surface. This principle has been used to develop the crystal orientation device with special X-ray. This kind of crystal orientation method with high precision, but because X ray has certain harm to human body, we should pay attention to the protection of operating personnel in use.