The word "Brinell hardness" is a term used in material science to measure the hardness of metals. Its spelling can be explained through the International Phonetic Alphabet (IPA) as 'brəˈnɛl hɑrdnəs'. The initial 'b' is pronounced with a brief stop of the vocal cords, while the 'r' is rolled or trilled. The 'i' is pronounced as a short 'i' sound, followed by a short 'e' sound, and then a stressed 'e', while the 'll' is pronounced as a double 'l'. The word is pronounced with a stress on the second syllable.
Brinell hardness is a measurement scale used to determine the hardness or resistance to indentation of a material. Named after the Swedish engineer Johan August Brinell, who developed the test method in 1900, it is regarded as one of the oldest and most widely-used methods for evaluating the hardness of materials.
The Brinell hardness test involves pressing a hard steel or carbide ball into the surface of a material, applying a specific force. The size of the resulting indentation is then measured and used to calculate the Brinell hardness number (BHN). This number indicates the material's ability to withstand deformation or penetration by a hard object.
The BHN is determined by dividing the applied force (in kilograms) by the curved surface area (in square millimeters) of the indentation left by the ball. This method is particularly suitable for measuring the hardness of metallic materials that are too coarse or rough for other types of hardness tests.
The Brinell hardness scale typically ranges from very soft materials like plastics or lead with values below 100 BHN, to harder materials like stainless steel or hardened steel alloys which can have BHN values exceeding 600. It is important to note that the Brinell hardness test does not measure the material's strength, toughness, or its ability to resist wear or surface damage, but solely its resistance to indentation.
The word "Brinell" in "Brinell hardness" is named after Johan August Brinell, a Swedish engineer and metallurgist.
In the early 20th century, Brinell developed a test to measure the hardness of metals. This test involved indenting a material with a hardened steel ball and measuring the diameter of the resulting indentation. By dividing the applied load by the surface area of the indentation, Brinell created a scale to quantify the hardness of metals.
Over time, this test and the corresponding hardness scale came to be known as the "Brinell hardness test" and "Brinell hardness scale" respectively, in honor of Johan August Brinell and his contributions to the field of metallurgy.