How to choose diamond tools?

With their unparalleled performance advantages, diamond tools have become the only effective hard and brittle non-metallic materials processing tools recognized today. For example, only diamond tools can be used to process super-hard ceramics, and there are no other substitutes. Diamond grinding wheels are used to grind hard alloys and are 10,000 times more durable than silicon carbide. Using diamond abrasive instead of silicon carbide abrasive to process optical glass, the production efficiency can be increased several to several tens of times. The service life of the diamond polycrystalline wire drawing die is 250 times longer than that of the hard alloy wire drawing die. So how to choose diamond tools? 

Here is the content list:

l The characteristics of diamond tools

l The selection criteria for diamond tools

l The use skills and precautions of diamond tools

The characteristics of diamond tools

Diamond tools have the advantages of extremely high hardness and wear resistance, low friction coefficient, high elastic modulus, high thermal conductivity, low thermal expansion coefficient, and low affinity with non-ferrous metals. Diamond tools can be used for precision processing of non-metallic hard and brittle materials such as graphite, high wear-resistant materials, composite materials, high silicon aluminum alloys, and other tough non-ferrous metal materials. There are many types of diamond tools with significant performance differences. The structure, preparation methods, and application fields of different types of diamond tools are quite different.

The selection criteria for diamond tools

1. The choice of diamond particle size

When the diamond particle size is coarse and single, the diamond tool saw blade bit is sharp and the sawing efficiency is high, but the bending strength of the diamond agglomeration is reduced; when the diamond particle size is fine or coarse and fine particle size mixed, the diamond tool saw blade bit is durable The degree is high, but the efficiency is low.

2. Selection of diamond distribution concentration

Within a certain range, when the diamond concentration changes from low to high, the sharpness and sawing efficiency of diamond tool saw blades gradually decrease, while the service life gradually extends; but if the concentration is too high, the diamond tool saw blades will become dull. However, with low concentration and coarse particle size, the efficiency will be improved. Using the different functions of each part of the cutter head during sawing and using different concentrations, the cutter head forms an intermediate groove during the sawing process, which is beneficial to prevent the saw blade from deflection and improve the quality of stone processing.

3. The choice of diamond strength

The strength of diamond is an important index to ensure cutting performance. Too high strength will make the crystals difficult to break, and the abrasive grains will be polished during use, and the sharpness will decrease, leading to a deterioration of the performance of diamond tools; when the strength of diamond is not enough, it will break easily after being impacted and it is difficult to bear the heavy task of cutting. Therefore, the strength should be selected between 130 and 140N.

4. The choice of the binder phase

The performance of diamond tool saw blades do not only depend on the diamond but on the overall performance of the composite material of the cutter head formed by the proper cooperation of diamond and binder. For soft stones such as marble, the mechanical properties of the cutter head are required to be relatively low, and copper-based adhesives can be used. However, the copper-based binder has low sintering temperature, low strength and hardness, high toughness, and low bonding strength with diamond. When tungsten carbide (WC) is added, WC or W2C is used as the framework metal, with an appropriate amount of cobalt to improve the strength, hardness, and bonding characteristics, and a small amount of Cu, Sn, Zn, and other metals with low melting point and low hardness is added for bonding phase. The particle size of the main ingredient should be finer than 200 mesh, and the particle size of the additive ingredient should be finer than 300 mesh.

5. Selection of sintering process

As the temperature increases, the densification degree of the carcass increases, and the bending strength also increases. With the extension of the holding time, the bending strength of the blank carcass and diamond agglomerates first increases and then decreases. The sintering process at 800°C for 120s meets the performance requirements.

The use skills and precautions of diamond tools

1. Take a small amount of trimming

In order to reduce the dressing time of diamond tools, it seems that there is always a temptation to choose a larger dressing depth. This is an extremely wrong idea. The most suitable dressing depth must be selected to dress the grinding wheel. Choosing a too-large dressing depth will produce high a cutting temperature, reduce the service life of the dresser, and also remove the useful grinding wheel layer. The end result is that both the dresser and the grinding wheel of the diamond tool are damaged, which is counterproductive.

The best dressing amount is to restore the geometry of the grinding wheel of the diamond tool after several times of dressing, but also to produce a good grinding edge as the criterion. Use a single-point dressing tool to contact the diameter direction of the grinding wheel with an inclination angle of the axis line of 10-15o. This will cause the single-point dressing tool to have a sharpening effect when it rotates regularly. The dressing tool with multi-point contact does not need to be inclined at this angle. Instead, the entire end face of the dressing tool is in contact with the surface of the grinding wheel.

2. Keep cooling

The proper use of coolant when using diamond tools can speed up the dressing speed and increase the dressing power. According to experience, choosing a 3/8 inch diameter coolant can remove a lot of heat from the dresser and prolong the service life of the dresser.

Today, diamond tool technology has been well developed. And the popularity of diamond tools is very high, and gradually tends to the unification of international standards. If you are in the diamond tool business, Hubei Little Ant Diamond Tools CO., Ltd. is an ideal choice.