Microhardness of Carbon Products
Carbon products are widely used in a variety of industries, including automotive, aerospace, wind power, medical, and electronics. The microhardness is one of the most important parameters to measure the performance of carbon products. It refers to the material’s resistant to indentation, which is an important property when producing these products. In this article, we will discuss the various methods used to measure the microhardness of carbon products and the important parameters to consider in determining the quality of a carbon product.
The microhardness of carbon products is evaluated by indenting a sample with a small indenter, usually an indenter tip. The microhardness of the sample is then evaluated by measuring the indentation depth, or the size of the indentation. Typically, the microhardness is determined by a combination of two different tests: Brinell Hardness and Vickers Hardness.
The Brinell hardness test involves using a load of 500-3000kgf (approximately 5000-30,000N) applied to a indenter tip through a Brinell indenter. The depth of the indentation is measured with a microscope, and the measured indentation depth is converted to a numerical value using a nominal scale. This value is considered to be an indicative of the hardness of the material.
Vickers hardness testing is a more sensitive way of determining the hardness of a sample. It involves the use of a Vickers indenter and up to 10,000N load being applied through the indenter tip. Similar to the Brinell hardness test, the microscope is used to measure the indentation depth, and the value is then converted to a numerical value on a nominal scale.
In addition to the indentation tests, the microhardness of carbon products can also be evaluated using other methods such as scuffing tests and tensile tests. The scuffing test involves subjecting the sample to a cyclic loading and unloading procedure, with the results of the test being evaluated by viewing the surface abrasion markings on the sample. The tensile test is used to measure the strength of the material, and typically a maximum load capacity, maximum strain, and maximum stress are all measured in order to determine the microhardness.
When evaluating the microhardness of carbon products, it is important to consider the microstructure of the material. Carbon products can be made of different types of carbon fibers, such as graphite, carbon nanotubes, and carbon fibers. The type of carbon fibers used, the orientation of the fibers, the degree of crystallinity, and the amount of impurities present in the fibers all affect the hardness of the material. In addition, the type of binder used in the material will also affect the hardness of the sample.
Finally, it is also important to consider the environment in which the carbon product is exposed to when evaluating the microhardness. For example, if the carbon product is installed in an area with high humidity or temperature fluctuations, the microhardness of the material may be affected due to corrosion or other factors.
In conclusion, the microhardness of carbon products is an important parameter to consider when determining the quality of these products. The most common methods of measuring the microhardness are indentation tests, such as the Brinell Hardness and Vickers Hardness tests, as well as other methods such as scuffing tests and tensile tests. Factors such as the type of carbon fibers used and the binder used, as well as the environment in which the product is installed, should all be taken into account when evaluating the performance of the microhardness of the product.
