Search results
Results From The WOW.Com Content Network
Scratch hardness test or scratch test refers to any of a number of methods of measuring scratch hardness. Resistance to abrasion is less affected by surface variations than indentation methods. Scratch hardness is measured with a sclerometer. [1] Attempting to scratch a surface to test a material is a very old technique. [2]
The Turner-Sclerometer test consists of measuring the amount of load required to make a scratch. [1] [2] In test a weighted diamond point is drawn, once forward and once backward, over the smooth surface of the material to be tested. The hardness number is the weight in grams required to produce a standard scratch.
The test was developed by Frederick Knoop [2] and colleagues at the National Bureau of Standards (now NIST) of the United States in 1939, and is defined by the ASTM E384 standard. The advantages of the test are that only a very small sample of material is required, and that it is valid for a wide range of test forces.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
In microindentation hardness testing, a diamond indenter of specific geometry is impressed into the surface of the test specimen using a known applied force (commonly called a "load" or "test load") of 1 to 1000 gf. Microindentation tests typically have forces of 2 N (roughly 200 gf) and produce indentations of about 50 μm. Due to their ...
Here is what the most popular diamond shapes for engagement rings mean. While reading, think about which shape reflects you and your partner. Round Brilliant Cut: Traditional and Elegant
Diamond is the hardest known material to date, with a Vickers hardness in the range of 70–150 GPa. Diamond demonstrates both high thermal conductivity and electrically insulating properties, and much attention has been put into finding practical applications of this material. However, diamond has several limitations for mass industrial ...
The FBI are investigating the claims of a woman in Texas who says she is Diamond Bradley - a young girl who disappeared from her Chicago home more than 20 years ago in what became one of the city ...