Absolute Grinding Hardness
Grinding hardness is a measure of material’s hardness or the ability of material to resist grinding by abrasive forces. Grinding hardness is most commonly measured when working with metals. Grinding hardness is the ability of a material to resist grinding contact and to hold up against abrasive forces.
Grinding hardness can have several different definitions depending on who you ask. For example, a metallurgist may define grinding hardness as a measure of the material’s resistance to plastic deformation caused by grinding. A machinist may define grinding hardness as the ability of a material to resist erosion or wear from grinding or cutting.
In most cases, grinding hardness is measured using the Rockwell scale, which was developed in the early 1900s. This scale measures the depth of penetration of an impression made by a diamond cone-shaped indentor into the materials surface. The more penetration, the more resistant the material is to grinding. A higher Rockwell number indicates a harder material.
The Rockwell scale is not the only way to measure grinding hardness. The Vickers microhardness test is a more precise way to measure grinding hardness, although it is not as commonly used. This test uses a diamond indenter that is placed on a tiny area of the materials surface. The indentation is then measured with a microscope and the indentation’s size and shape are then used to give a hardness value.
The Brinell hardness test is also used to measure hardness. This test uses a tungsten carbide ball as an indenter and measures the area of indentation in the materials surface. This test is used for softer materials and is often used to measure the hardnesses of materials such as cast iron.
Absolute grinding hardness is the ability of a material to resist grinding forces with no plastic deformation. This is a measure of the maximum hardness of a material and is typically higher than the measured hardness using the Rockwell scale or Vickers microhardness test.
Brazing is one common method of increasing a material’s absolute grinding hardness. This process involves melting a metal alloy to a specific temperature and pouring it into the area to be joined. The molten alloy then bonds the two pieces together and creates a stronger bond. This increases the material’s hardness and resistance to grinding forces.
Heat treating is another method of increasing a material’s absolute grinding hardness. This process involves heating a material to a specific temperature and then cooling it rapidly. This rapid cooling process changes the material’s crystal structure, which can increase its resistance to grinding forces.
Since grinding hardness measurements are often used to judge the suitability of a material for a particular application, it is important to have an accurate measure of a material’s absolute grinding hardness. This is why it is important to understand the many ways that grinding hardness can be measured and to always use methods which will yield the most accurate results.
