Influence of resin grinding wheel characteristics on performance of grinding wheel

(1) Abrasive material:

The commonly used abrasives for cutting grinding wheels are brown corundum (A), white corundum (wA), black corundum (BA), black silicon carbide (c), etc. The most commonly used is brown corundum, because brown corundum has high hardness, toughness, The particles are sharp, the applicability is strong, and the price is lower than other abrasives. Brown corundum is divided into primary sand and secondary sand according to whether it is fully reduced during smelting, mainly in the chemical composition: the Al2O3 content of primary sand is greater than or equal to 94.5; the Al2O3 content of secondary sand is less than 94.5%; generally 85% The hardness of secondary sand is lower than that of primary sand, but the price is also lower; brown corundum is suitable for the processing of various carbon steels and general alloy steels; white corundum has higher hardness than brown corundum. It has high brittleness and low grinding heat. Because of its high price, it is used when the workpiece requires small thermal deformation. It is also used as mixed abrasive for processing special materials; the Al2O3 content of black corundum is 70-85%, and the Fe2O3 content is 7-9%. , low hardness, poor cutting force, but the price is also cheap; black silicon carbide has high hardness and good brittleness, sharp cutting edge, good self-sharpening performance, good thermal conductivity, and has advantages in processing non-ferrous metals, plastics, rubber and cast iron.

(2) Abrasive particle size:

The commonly used particle size is: 22#-80#, and the cutting efficiency is low when the particle size is fine.

(3) Wheel hardness:

Common hardness: P, Q, R; N, S; generally use a harder grinding wheel to reduce wheel wear. Its hardness is controlled by factors such as the amount of binder, molding density, firing temperature and firing time.

(4) Binder:

Commonly used resin binders are: powder phenolic resin, liquid phenolic resin. Powdered phenolic resin has good processability, the molding density of the abrasive tool is slightly smaller, the texture number is slightly larger, and the price is higher than that of the liquid phenolic resin; the price of the liquid phenolic resin is low, but the material is easy to agglomerate and the mixing material is not easy to be uniform, which is easy to cause localized abrasives. hard.

(5) Organization:

The organization number of the cutting wheel should be slightly larger to improve the cutting efficiency: if it is too large, it will affect the strength. The commonly used organization numbers are 3 to 7.