Formulation design of ceramic bond grinding wheel -- dosage of bond

The dosage of the binder in the formula is determined on the basis of determining the type of abrasive (including mixed abrasive) particle size (including mixed particle size) and the hardness of the grinding tool type.

Is another kind of abrasive as 100, outside the binder of 100 to join quality so that's the only calculate the benchmark is different, the amount of binder in the conversion formula for each other is very important, directly affect the quality of abrasive products formula and production process, performance at the specified abrasive formula, the dosage of the binder is mainly from the following several aspects to consider.

(1) the hardness of the abrasive tool

The hardness of the abrasive tool is the main basis to determine the amount of the binding agent. Generally speaking, when other conditions remain unchanged, the higher the hardness of the abrasive tool, the more the amount of the binding agent.

This is because, by increasing the dosage of the binding agent in the formula, the bridge of the binding agent between abrasive particles will be coarser, and the consolidated strength of abrasive particles will be relatively increased. Therefore, it is necessary to increase the effect of external force to break and fall off abrasive particles, which reflects the improvement of the hardness of abrasive tools.

On the contrary, if the dosage of the binder is reduced, the hardness of the abrasive tool will be reduced.

Experiments have shown that the dosage of the binding agent is about 2% for each increase or decrease of a small degree of hardness, while the soft degree of hardness is 1.0%~1.5%, and the sensitivity of the increase or decrease of the combined dose to the change of hardness is reduced to 2%~3% after mid-hardness.

When the formula of grinding tool is specified, the minimum increase and decrease of the adjusted binding dose is generally 0.5%, which is estimated to be equal to 25% of small hardness.

Due to the limit of current production level, there are many factors affecting the fluctuation of hardness, so it is not necessary to reduce the minimum adjustment to 0.1%. As this effect is not big enough, it will also increase the trouble of calculating ingredients.

(2) type and particle size of abrasive

Different types of abrasive under the same hardness, the amount of binder is different.

Magazine, for example, because of the brown fused alumina contains more than white corundum, and these impurities in abrasive when burnt, ability to respond to action and into the melt of the binder, improve the high temperature of mixture of liquidity and wettability, consolidation degree between the abrasive grain strengthening, which improves the hardness of grinding tool, therefore, under the same hardness, the combination of brown fused alumina abrasive agent less.

When the abrasive types are the same, different abrasive particles have different amounts of binder under the same hardness.

Because of the larger specific surface area of fine grit abrasive, more binders are required to be distributed on each abrasive surface to achieve the same degree of consolidation as coarse grit.

When the content of impurities is large, these impurities often act as a catalyst and strengthen the consolidation strength between abrasive grains. At this time, the dosage of the binding agent is reduced.

(3) type of binding agent

Other conditions are the same, the amount of sintering bond is less than that of sintering bond, and the difference between the two is related to the type of bond.

Due to almost all the sintering binders become glass phase at the sintering temperature, they are generally homogenous and the binders are distributed evenly.

However, only a small amount of glass phase is produced by the sintering binder at the sintering temperature, and a considerable part of crystalline phase remains in the binder. The density of the microstructure is extremely poor, and there are many microcracks. The "bridge" of the binder has low relative strength, which is easy to break and fall off, showing soft hardness of the abrasive tool.

(4) grinding tool forming method

When using different molding methods, the same binding agent, the same hardness, the dosage of the binding agent is different, and the amount of the binding agent of water pouring molding is more than that of pressing molding.

This is because the molding material is in the state of mud during the water casting molding, and it is formed into the blank of the abrasive tool by its own force deposition, the structure is relatively loose.

The moulding material is compacted under the effect of forming pressure, so the structure is tight and the binding dose required for the same hardness is less.