Ballast track is concrete or asphalt mortar to replace loose ballast and composed of track structure type, it has the characteristics of high track stability, good stiffness uniformity, strong structure durability and less maintenance work, for high-speed railway has a better adaptability than the traditional ballast track. Of slab without a frantic jumble track research in China is carried out along with the continuously go deep into the research of high speed railway, high-speed railway track plate is no ordinary concrete products, because of the complexity of the track plate used in concrete and the track plate size is relatively strict, must ensure that the support rail grinding machine precision steel erection error is less than 0.3 mm, Therefore, high requirements are put forward for the tool manufacturing industry.

A wafer goes through three changes before it becomes a real semiconductor chip: first, it is cut from a lump of ingots into wafers; In the second step, a transistor is engraved on the front of the wafer by the previous step. Finally, the wafer is packaged, that is, cut through the process to make a complete semiconductor chip. In this process, the wafer is cut into a number of hexahedral shape of the single chip, the process is called "Singulaton", and the process of Sawing the wafer into a rectangular shape is called "Die Sawing".

Double-disc grinding machine can grind workpieces using a through-feed, plunge-cut or oscillation process, depending on the respective requirements. The compact and rigid machine configuration ensures the greatest precision level of component with the shortest transfer times.

Through-feed process radial/linear for the shortest cycle times

The production of grinding vibration not only affects the machining accuracy, but also causes the workpiece surface roughness can not meet the requirements, so that many problems occur in the working state of the workpiece.

There are two reasons for the grinding vibration: one is the forced vibration of the workpiece; the other is that the machining parameters are unreasonable, which causes the self-excited vibration of the workpiece.

The first type of vibration exists in the environment, even if there is no grinding, the grinding machine is started, these vibrations exist. It happens that some vibration frequencies are close to the resonant frequencies of the workpiece, causing the grinding vibration marks. Suspected components that produce these vibrations include bearings mounted on rotating parts, driving belts, and hydraulic components.

The second type, is the role of periodic changes in processing, its frequency coincides with the resonant frequency of the workpiece, causing vibration. This kind of vibration can be reduced by adjusting the machining parameters. Or choose a low hardness, a bit of coarse grain grinding wheel. Because if the rigidity of the grinding machine is different, the sharp wheel can be used to reduce the grinding force, and the vibration grain can be reduced to a certain extent.

Cemented carbide is tungsten carbide, titanium carbide and other metal carbide as hard phase, with cobalt and other metal as adhesive, made by powder metallurgy method, has a high hardness (up to HRA89-93, Microhardness of 1300-1800N/mm2), low thermal conductivity (16.75-79.55W/m·K), low bending strength (3.0-4.5gpa) and large elastic wear (540-650gpa). It is a hard brittle material at room temperature, showing different grinding requirements from steel and other materials. Used to using green silicon carbide grinding wheel for grinding carbide, but because of the high silicon carbide abrasive hardness is not enough (microhardness n/was 32000-34000), when grinding carbide abrasive wear passivation easily, cause the increase of grinding force, grinding temperature is exorbitant, leads to the formation of a cutting tool surface crack defects, such as silicon carbide grinding wheel threshing too fast at the same time, Grinding wheel shape is not easy to maintain, resulting in tool size instability.

  Because it is often restricted by the diameter of the inner hole of the workpiece, the diameter of the inner circle processing is usually low, the speed is often affected by the speed of the inner spindle of the equipment, and the circumferential speed of the ceramic diamond grinding wheel is often lower than 30-35 m/s.  Therefore, vitrified diamond grinding wheels are usually more efficient in machining roughness and cylindrical grinding