The cutting disc is the most important type of grinding tool in grinding. The cutting disk is a porous body which is prepared by adding a binder to an abrasive, compacting, drying and baking. Due to the different abrasives, binders and manufacturing processes, the characteristics of the cutting discs vary greatly, which has a significant impact on the quality, productivity and economy of the grinding. The characteristics of the cutting disc are mainly determined by factors such as abrasive, strength, bonding agent, hardness, organization, shape and size.
There are many types of cutting discs:
According to the abrasive used, it can be divided into ordinary abrasive (corundum and silicon carbide) cutting discs and natural abrasive superabrasives and (diamond and cubic boron nitride, etc.) cutting discs;
According to the shape, it can be divided into a flat cutting disc, a bevel cutting disc, a cylindrical cutting disc, a cup-shaped cutting disc, a disc-shaped cutting disc, etc.; according to the bonding agent, it can be divided into a ceramic cutting disc, a resin cutting disc, a rubber cutting disc, a metal cutting Disk and so on. The characteristic parameters of the cutting disc mainly include abrasive, viscosity, hardness, bonding agent, shape, size and the like.
Since the China cutting disc for metal is usually operated at high speed, the slewing test (to ensure that the cutting disc does not break at the highest working speed) and the static balance test (to prevent machine vibration during operation) should be performed before use. After the cutting disc has been in operation for a period of time, it should be trimmed to restore the grinding performance and the correct geometry.
The cutting discs on the grinding machine are characterized by:
The grinding zone is hot due to severe friction. This can cause stress and deformation of the workpiece and even burn the surface of the workpiece. Therefore, a large amount of coolant must be injected during grinding to reduce the grinding temperature. The coolant can also act as chipping and lubrication.
The radial force during grinding is large. This causes the machine tool-cutting disc—the elastic retraction of the workpiece system so that the actual depth of cut is less than the nominal depth of cut. Therefore, when the grinding is about to be completed, the knife should not be used for light grinding to eliminate the error.
After the abrasive grain is blunt, the grinding force also increases, causing the abrasive grain to break or fall off, and the sharp edge is re-appeared. This characteristic is called “self-sharpness”. Self-sharpening enables grinding to proceed normally within a certain period of time, but after a certain working time, manual dressing should be performed to avoid vibration, noise and damage to the surface quality of the workpiece caused by increased grinding force.
Due to the high hardness and heat resistance of the disc grinding disc itself, grinding can process materials with high hardness, such as hardened steel and hard alloy.
The characteristics of the aluminum flat cutting disc and the grinding machine determine that the grinding process system can perform uniform micro-cutting, generally ap=0.001~0.005mm; the grinding speed is very high, generally up to v=30~50m/s; the grinding machine has good rigidity; the hydraulic transmission is adopted. Therefore, the grinding can economically obtain high processing precision (IT6 to IT5) and small surface roughness (Ra = 0.8 to 0.2 μm). Grinding is one of the main methods of finishing parts.