The basic elements of resin abrasives are abrasive type, abrasive particle size, abrasive hardness, bond dosage, abrasive organization, forming density or strength, etc.
The relationship between abrasive type and bond dosage:
Under the conditions of the same particle size and molding density, to make abrasive tools of the same strength level, the amount of bonding used by silicon carbide abrasives is more than that of corundum abrasives. This is because:
1. The density of corundum abrasive (3.95~3.97g/cm3) is larger than that of silicon carbide (3.12~3.20g/com3). When the quality and particle size are the same, the number of particles of silicon carbide abrasive is more than that of corundum abrasive, so the total surface area is larger.
2. Silicon carbide abrasives are in the shape of flakes and needles, while corundum abrasives are mostly diamond-shaped. This further increases the total surface area of the silicon carbide abrasive.
Therefore, when other conditions are the same, the surface area of silicon carbide abrasives is large, so more binders are required to bond.
The relationship between abrasive particle size and bond dosage:
1. Under the same abrasive tool strength (or hardness), abrasive type and molding density (or pressure), the bonding amount increases with the increase of particle size. That is, the finer the abrasive, the more bond is required. This is because of the same quality of abrasive, the finer the particle size, the greater the number of particles, and the greater the total surface area. Therefore, more binder is required to surround the skin.
2. Other things being equal, the amount of binding used for mixed particle sizes is less than for a single particle size. This is because the fine-grained abrasive fills the gaps between the particles of the coarse-grained abrasive, replacing (or occupying) a part of the volume of the binder, thus reducing the amount of the binder. Resin flake grinding wheels or cymbal-shaped grinding wheels often use mixed-grain abrasives to improve the strength of the grinding wheel, which is based on this principle. Therefore, although the amount of bonding used in the abrasive tool with mixed-grained abrasive is the same as that of the single-grained grinding wheel, the strength is significantly improved.
The relationship between combined dose and hardness (or strength):
The changes in hardness and strength of abrasive tools are generally consistent. Bond dosage is one of the main factors affecting the hardness or strength of abrasives. In the case of the same abrasive type, particle size and forming density (or pressure). Increasing the binding dose of the formula can improve the hardness and strength of the abrasive tool. Conversely, reducing the amount of bonding in the formula reduces the hardness and strength of the abrasive tool. This is because when the amount of bonding increases, the bonding agent bridge between the abrasives becomes thicker, making the abrasive grains more firmly bonded and more resistant to external forces.
The relationship between forming density (or pressure) and abrasive hardness:
In the case of the same abrasive type, particle size and bond amount, with the increase of the forming density (or pressure), the hardness and strength of the abrasive tool also increase. This is because the molding density (or pressure) increases, the density of the abrasive tool also increases, the distance between the abrasive grains is reduced, the bond bridge is thicker, and the abrasive grains are bonded more firmly, so the hardness and strength of the abrasive tool be increased. therefore. Adjusting the molding density (or pressure) of the abrasive tool is the main method to adjust the hardness and strength of the abrasive tool. Especially for high-hardness abrasives, the effect of increasing the forming density is often more significant than increasing the amount of bonding.
To manufacture an abrasive tool with the same hardness, as the molding density (or pressure) increases, the amount of binder can be reduced accordingly. Therefore, the molding density (or pressure) and the amount of binder are the main reasons for controlling the hardness and strength of the abrasive tool.
Recipe adjustment:
The same level of hardness (or strength) can be achieved in three ways:
1. More binding dose, less molding density;
2. Less binding dose, greater molding density;
3. General binding dose, general forming density.
In general, when specifying the scheme, it should follow the law that as the hardness or strength increases, the binding dose and molding density also increase once.
