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The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. [1] The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter ...
A variety of hardness-testing methods are available, including the Vickers, Brinell, Rockwell, Meyer and Leeb tests. Although it is impossible in many cases to give an exact conversion, it is possible to give an approximate material-specific comparison table for steels .
ASTM Specification E384, for example, states that the load range for microhardness testing is 1 to 1000 gf. For loads of 1 kgf and below, the Vickers hardness (HV) is calculated with an equation, wherein load (L) is in grams force and the mean of two diagonals (d) is in millimeters:
A graph of Vickers 150kg versus the other scales makes sense. Vickers 150kg scale covers a very large range of hardness. The Mohs scale of hardness is so different from the metals hardness scale, that comparison is difficult. ASTM E18 for rockwell, ASTM E10 for Brinell define the limits of rockwell and brinell testing.
A Vickers hardness tester. There are three main types of hardness measurements: scratch, indentation, and rebound. Within each of these classes of measurement there are individual measurement scales. For practical reasons conversion tables are used to convert between one scale and another.
This page was last edited on 16 November 2024, at 12:16 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
The point of a hardness scale is the comparison of materials to each other. In other words a difference of a (multiplicative) constant divides out when comparing materials. It is said that the Vickers hardness is not a pressure, but it seems to me to be proportional to a pressure, and therefore a pressure.
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.