Difference between, Brinell,Rockwell and Vickers Hardness Test
What is Hardness?
Measurement of Hardness:
No specimen preparation required
The specimen surface can be rough
Specimens need to be prepared
Hardness value directly readable, no optical evaluation required
Good illumination of the test indent is important for ensuring correct evaluation
of the test indent (e.g. with the aid of a ring light).
Due to the need to conduct optical indent evaluation, Vickers hardness testers
must be equipped with an optical system
Quick and cost-effective process
The process is slow (by comparison with the Rockwell method). The test cycle
takes somewhere between 30 and 60 seconds
The process is rather slow. The test cycle takes somewhere between 30 and 60
Limitation in applying the method on thin specimens of very hard materials
Non-destructive testing is possible
Not always the most accurate hardness testing method
High risk of deforming the material to be tested when testing in the macro range
with high test loads
More expensive to purchase than Rockwell testers due to optical system
The test location must be completely free of all contamination (e.g. scale,
foreign bodies or oil)
The surface quality of the specimen must be good, because the indent is measured
The surface quality of the specimen must be good (ground and polished)
The indenter has unknown effects on the test results
Relatively large test indents that are easier to measure the rather small Vickers
Only one type of indenter
With increasing hardness, it becomes increasingly difficult to distinguish between materials
Can be used for testing non-homogeneous materials (e.g. castings)
The Vickers method can be used with any and all materials and test specimens
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