How are diamond and CBN grinding wheels dressed?
1) Grinding dressing method: Use ordinary abrasive grinding wheels and diamond grinding wheels to grind against each other. Through friction and extrusion force, the bond loss causes the diamond particles to fall off, exposing sharp diamond particles.
Advantages: simple and convenient operation, short consumption time, stable effect, and low cost.
Disadvantages: low dressing efficiency, poor precision, and difficulty controlling the shaping quality.
Application: mostly used for diamond and CBN grinding wheels with ceramic and resin bonds.
2) Spark discharge dressing method: The grinding wheel is connected to the positive electrode, the tool electrode is connected to the negative electrode of the power supply, and there is a voltage between the tool electrode and the grinding wheel, which generates spark discharge, and the metal bond is vaporized at instantaneous high temperature to fully expose the diamond abrasive particles.
Advantages: It can ensure the grinding accuracy and shaping accuracy of the grinding wheel.
Disadvantages: Slow shaping speed.
Application: Mostly used for the dressing of metal bond diamond and CBN grinding wheels.
3) Electrolytic dressing method: Connect the DC power supply, use the metal bond grinding wheel as the electrolytic anode, the tool electrode as the electrolytic cathode, and spray the electrolyte to form an electrolytic circuit. Under the action of electrolysis, the metal bond dissolves in the electrolyte is carried away by the flowing electrolyte, and then is mechanically dressed.
Advantages: It can be electrolytically dressed online, while ensuring shaping and sharpening, with short dressing time and low grinding heat, effectively avoiding abrasive carbonization caused by excessive temperature.
Disadvantages: Low shaping accuracy, complex process, and high cost.
Application: Mostly used for dressing metal bond diamond and CBN grinding wheels.
4) Diamond roller dressing method: The rolling wheel is made by electroplating or powder metallurgy to embed a large number of diamond particles on the surface of the carbide roller. During the rotation of the rolling wheel, some uneven abrasive particles on the surface of the diamond grinding wheel can be crushed or fallen off, so that the diamond grinding wheel maintains its cutting performance.
Advantages: High dressing accuracy and high dressing efficiency.
Disadvantages: The equipment must have its roller device, and the roller cost is high.
Application: Vitrified bond diamond and vitrified CBN grinding wheels
In practical applications, it is necessary to comprehensively consider factors such as workpiece material, processing technology, grinding wheel type, and equipment conditions to select the appropriate dressing method. At the same time, to ensure the dressing effect, the diamond grinding wheel needs to be inspected and dressed regularly to maintain good grinding performance and processing accuracy.
