KNOOP HARDNESS Meaning and
Definition
-
Knoop hardness is a measure of a material's resistance to indentation or scratching by a sharp, pyramidal diamond indenter. It is a microhardness test method that is primarily used for testing brittle materials or materials with extremely high hardness, such as ceramics, mineral samples, glass, and thin metallic coatings.
The Knoop hardness test was developed by Dr. Friedrich Knoop in the early 1930s as an alternative to the Vickers hardness test, which uses a different indenter shape. The Knoop indenter has a rhombic-based pyramid shape with an elongated elongated triangular base, allowing for a higher ratio of applied load to surface area compared to the Vickers indenter. This makes it suitable for measuring the hardness of thin films or small areas.
In the Knoop hardness test, a specimen is typically prepared by cutting and polishing its surface. The Knoop indenter is then pressed into the material under a controlled load for a specified time. The diagonal length of the indentation is measured under a microscope, and the Knoop hardness value is calculated using a formula that incorporates the load and the length of the long diagonal.
The Knoop hardness value is expressed in units of pressure, either kilogram-force per square millimeter (kgf/mm²) or gigapascals (GPa). It provides a quantitative measure of a material's resistance to plastic deformation or indentation, allowing for comparisons between different materials or regions within a material.
Common Misspellings for KNOOP HARDNESS
- jnoop hardness
- mnoop hardness
- lnoop hardness
- onoop hardness
- inoop hardness
- kboop hardness
- kmoop hardness
- kjoop hardness
- khoop hardness
- kniop hardness
- knkop hardness
- knlop hardness
- knpop hardness
- kn0op hardness
- kn9op hardness
- knoip hardness
- knokp hardness
- knolp hardness
- knopp hardness
- kno0p hardness
Etymology of KNOOP HARDNESS
The etymology of the term Knoop hardness can be attributed to its creator, Frederick Knoop. Frederick Knoop was an American engineer and metallurgist who developed a method of measuring the hardness of materials in the early 20th century. In 1939, he introduced the Knoop hardness test, which involved using a pyramidal diamond indenter to indent the surface of a material. The test was specifically designed to measure the hardness of brittle materials, such as ceramics, glass, and certain metals. Over time, this method became widely used and the hardness scale was named after Frederick Knoop, hence the term Knoop hardness.
