1. Analysis of Wear Characteristics of Grinding Wheel

To improve the grinding ratio of grinding wheels, we need to explore the wear mechanism of grinding wheels. The wear process of artificial diamond grinding wheels in grinding is relatively complex, and there are many types of wear. There are mechanical, adhesive, frictional, diffusive, chemical, thermal effects, and other methods, but the main methods are as follows:

(1) Due to the poor bonding between diamond abrasive particles and the binder, the diamond abrasive particles fall off prematurely under the effect of grinding force.

(2) Due to the occurrence of grinding heat, the physical and mechanical properties of the bond change, resulting in a decrease in the strength of the bond and promoting wheel wear.

(3) Diamond resin grinding wheels generally use RVD grade abrasives, which have many needle like shapes and are prone to crystal fragmentation under the effect of grinding force, promoting wheel wear.

(4) The interaction between the diamond crystal surface and the processed data causes micro wear at the top of the diamond abrasive operation, and sometimes under the effect of grinding force, the diamond surface undergoes micro graphitization, promoting wheel wear.

Through the above analysis and investigation of the surface description of resin bonded diamond grinding wheels after grinding, it was found that there were many holes left after the diamond fell off. From this, it can be inferred that the poor combination of abrasive particles and binder is the main reason for the premature drop of diamond abrasive and the low grinding ratio of the grinding wheel. This article conducts experimental research on the replacement of wetting agents with coupling agents, in order to find ways to reduce premature drop of diamond abrasives and improve the grinding ratio of resin bonded diamond grinding wheels.

2. Experimental methods

2.1 Coupling agent experiment

How to Improve the Grinding Ratio of Artificial Diamond Resin Grinding Wheel

We use coupling agents instead of wetting agents according to our experience formula, and use relevant grinding wheel manufacturing techniques to produce 120x20x20 (m?) test strips and several "8" blocks. The hot pressing temperature is 210 ℃, the hot pressing time is 20min, the hardening temperature is 230 ℃, and the hardening time is 4h

Conduct impact strength and tensile strength tests on the production samples separately, and explore the relationship between coupling agent dosage and impact strength and tensile strength.

The Relationship between the Percentage Content Change of Coupling Agent and the Tensile Strength of Test Blocks

From the analysis of test results, it can be seen that with the addition of coupling agent content, the impact strength and tensile strength gradually improve, but there are values when reaching a certain content; Afterwards, as the coupling agent content continues to be added, the impact strength and tensile strength gradually decrease. From this experiment, it can be seen that adding a certain proportion of coupling agent can improve the adhesion between the bond and diamond abrasive particles.

2.2 Grinding wheel production

We will investigate the microscopic description of the 1 # and 2 # grinding wheels after grinding experiments.

How to Improve the Grinding Ratio of Artificial Diamond Resin Grinding Wheel

The Relationship between the Percentage Content of Coupling Agents and the Impact Strength of Test Blocks

We use the experience formula to choose a wetting agent to make one piece of grinding wheel, and the other piece is made using a coupling agent instead of the wetting agent according to the relevant process. Hot pressing at 210 ℃ for 2 hours, hardening at 235 ℃ for 8.5 hours

2.3 Grinding experiment

2.3.1 Experimental conditions

Machine tool: M7210A surface grinder

Grinding dosage: grinding wheel speed n=2100r/min

Grinding depth 0.02~0.028mm

Workbench speed 1-6m/min

Grinding fluid: kerosene

Workpiece: YG8 hard alloy

Grinding wheel: 1A1/T2250x25x75D100/120B

75 (1 #, wetting agent)

1A1/T2250x25x75D100/120B

75 (2 #, coupling agent)

2.3.2 Determination of grinding ratio

(1) Clean the grinding wheel and workpiece separately with acetone to remove oil stains and other impurities, and then place them in a drying oven. Dry them at 110e to constant weight and cool them to room temperature.

(2) Separately weigh the workpiece and grinding wheel before grinding. (3) Conduct grinding experiments according to grinding conditions.

(4) After grinding, weigh the grinding wheel and workpiece again according to the above requirements.

How to Improve the Grinding Ratio of Artificial Diamond Resin Grinding Wheel

Table 1 Grinding Comparison Experiment Results

(Note: Grinding ratio=Metal removal component P Grinding wheel wear component)

3. Microscopic phenomena on the surface of grinding wheels

We will use the naked eye to distinguish the 1 # and 2 # grinding wheels through grinding experiments. The surface of the 1 # grinding wheel has more diamonds falling off, and there are many holes on its surface; There are fewer diamonds falling off the surface of the 2 # grinding wheel, and there are also fewer holes on its surface.

How to Improve the Grinding Ratio of Artificial Diamond Resin Grinding Wheel

Description of the outer surface of Jingxiu Sharp 2 # grinding wheel

How to Improve the Grinding Ratio of Artificial Diamond Resin Grinding Wheel

It can be seen that there are overall differences between the two. The bonding between 1 # bond and diamond abrasive is not tight, while the bonding between 2 # bond and diamond abrasive is more tight, which is consistent with the grinding ratio of the two.

4. Conclusion

(1) From a microscopic perspective, the degree of tightness of the bonding agent and abrasive between the two is different.

(2) Choosing coupling agents is an effective way to improve the grinding ratio of resin bonded diamond grinding wheels.

(3) After grinding, visually inspect the surface cavities of both, and select a coupling agent to make the grinding wheel with fewer surface cavities compared to a wetting agent.

(4) The experimental results show that the grinding ratio of wheels made with coupling agents can increase by up to 25. 5% compared to wheels made with wetting agents

Article source: Resin wheel manufacturerhttp://www.jm-nanhua.com