With the development of science and technology, in the aerospace, aviation, shipbuilding and machinery industries, the use of high-strength, high-hardness materials has become more and more common, these materials are often difficult to process with ordinary grinding tools. In this case, there are generated and developed. Super abrasive abrasives.
Superhard abrasive tools are abrasive tools made of diamond and cubic boron nitride. Its superiority is highlighted in the following aspects.
1. It can process high hardness materials that are difficult to process with ordinary abrasive tools.
2. Less wear during processing, under reasonable use conditions, can obtain good economic results。
3. The shape and size of the grinding wheel change slowly, and the service life is long. Therefore, it is rarely trimmed and the sharp cutting edge can be maintained for a long time, so that the grinding efficiency is high and power consumption is low.
4. The low grinding temperature can reduce the number of defects and avoid defects such as cracks and burns.
Diamond is currently known as a hard material in the world, but natural gangue resources are limited, difficult to extract and expensive. Now focusing on research and vigorously develop synthetic diamond as a substitute for natural diamond.
Synthetic diamond boring abrasives have good grinding performance. The consumption of grinding wheel is small, but the use requirement is high and it is not suitable for heavy load boring. The performance of the natural diamond abrasives is not as good as that of artificial diamond abrasives. The loss of the grinding wheel is high and the cost is high. However, a larger amount of grinding can be used.
Because of its high hardness, diamond abrasive tools have good wear resistance, sharp edges and corners, and low friction factors. However, when the gangue is at a temperature of 600-700 or more, its carbon atoms are easily diffused into the iron dead material to form iron carbide. It will accelerate diamond wear and it is not suitable for grinding steel and other plastic materials.
Cubic chloride group (cBN) is another new type of superhard material. It has cubic crystals made of cubic boron chloride under the conditions of high temperature and pressure, and its hardness is about 1.5 times that of corundum. It is lower than diamond, but it can withstand high temperatures, and its thermal stability and chemical stability are excellent. In diamond, therefore, cubic boron chloride abrasives are suitable for processing hard and tough ferrous metals. However, it easily reacts with water under high temperature conditions and is therefore generally used for dry grinding.