Causes of cracks in abrasives


2022-05-17 15:35

Abrasives are tools used for grinding, lapping and polishing. Most of the abrasives are artificial abrasives made of abrasives and binders, and there are also natural abrasives that are directly processed from natural ore rocks. In addition to being widely used in machinery manufacturing and other metal processing industries, abrasive tools are also used in the processing of non-metallic materials such as food processing and glass. In the production process, cracks are a relatively common waste factor. The following manufacturers will introduce the reasons for the cracks in abrasive tools:

The damage of general materials is caused by two points: one is that there are cracks inside the abrasive material; the other is that such cracks can expand in the material until they crack. All defects in the material, including micro-cracks, small pores and places where impurities are concentrated, and places where the arrangement is loose, can become the source and cause of cracks, which are called crack sources. Any crack is generated from the crack source under the action of external force. The source of the crack is often so small that it cannot be detected by the naked eye, but under the microscope, it can be seen that there are many tiny cracks - tiny cracks, as well as pores and impurities, which are the origin of the cracks.

There are two factors that cause abrasive tool cracks: mechanical shock and thermal shock. Mechanical shocks include: flipping, bumping and beating during molding, impact during handling, excessive pressure during processing, and excessive knife feeding; thermal shocks include: excessive heating during firing, excessive cooling rate during firing, and excessive drying rate Wait too fast.

The source of the crack is brought in by the abrasive tool during the production process. No material can be completely free of defects, but this does not mean that cracks will inevitably occur if the product has defects; It cannot deform plastically like metal. It is easy to concentrate stress on a certain part, so that this part of the defect - the source of the crack is quickly transformed into a crack. Once the internal crack is formed and reaches a certain critical size, it is very easy to expand. The internal stress immediately gathers on the crack and expands to both ends. The abrasive tool cannot absorb external force through its own shape change like metal. The energy brought in can only be absorbed by the natural way of generating new appearances. The expansion of cracks means the formation of two new appearances. In this way, the crack rapidly expands and the new surface rapidly increases until the structure of the crack or crack, so that all the applied energy is converted into the energy produced by the new surface, which is the process of crack formation.

The natural formation and expansion of cracks occur in a very short period of time, or even for a while, which can really be said to be splitting. The property of an abrasive tool that cannot withstand strong vibration and impact is called brittleness. The measure of brittleness can be expressed by the energy required to form a new surface of a unit, which is called cracking work. The greater the cracking work, the greater its toughness.

From this, we can understand that the abrasive tool is brittle and cannot withstand impact, so whether it is a semi-finished product or a finished product, it should be handled with care during the use of the abrasive tool and the processing of the product, and be careful to cause the abrasive tool to crack. Factors to avoid improper operation to expand the cracks of the abrasive tool and damage.

Causes of cracks in abrasives



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