Hardness is defined as the resistance of a material to permanent indentation or scratch marks. Hardness tests help examine a material’s properties, and there are four main types of hardness tests in Malaysia.
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Rockwell Hardness Test
The first on our list is the Rockwell test, which is the most preferred test method. The Rockwell test is easier to perform and is perceived to be more accurate and faster than the other types of hardness tests.
You can utilise this method on all metals, with three exceptions:
- If the test metal structure or surface conditions could lead to too many variations
- If the indentations would be too large for the application
- If the sample size or form prevents its use
The three stages of the Rockwell method:
- A diamond or ball indenter is used to apply a preliminary load briefly.
- After removing the preliminary load, the indentation is measured, and the load is then increased and applied (referred to as major load). The preliminary load is then re-applied for a short time after the major load is removed.
- Lastly, the indenter is removed to measure the final indentation. The difference between the first and last indentation depth measurements determines the material’s Rockwell hardness.
Brinell Hardness Test
As the first standardised test to be extensively used among the five types of hardness tests, the Brinell test involves pressing a carbide ball indenter into the surface of the material with a constant applied force for a set period.
The Brinell technique produces a round indentation that can be quantified and used to derive a hardness value when combined with the applied load. However, this method is slower and more destructive than other methods, as it leaves a significant indentation in the material.
Vickers Hardness Test
Third in our types of hardness test list is the Vickers test, also known as the Microhardness test method. This approach is generally used for thin parts, small material sections or case depth work.
For the Vickers method, a range of light stresses is measured and translated to a hardness value using a diamond indenter. As the test indentation is a bit small, test samples must be properly polished to measure the size of the impressions.
This type of hardness testing is suitable for almost everything, from metals to ceramics and composites. Additionally, it’s better to section the test material to ensure the sample can fit seamlessly into the tester.
Mohs Hardness Test
Last but not least, the Mohs hardness test was one of the first attempts to compare the hardness of mineral materials. Its scale ranges from 1 to 10, with higher numbers indicating the capacity of the material to survive scratching by harder minerals.
Listed below is the Mohs scale of mineral hardness:
Since they’re quite expensive, the Mohs test rarely uses the actual minerals listed in the scale above.
Instead, this simple method entails scratching the material’s surface with another object comparable to those materials. For instance, a steel file is used to represent the hardness scale 6.5.
Starting at the soft end of the scale, the testing procedure progresses until one of the minerals or materials creates an indentation.
In regard to the Mohs hardness test, the applied force is not continuous, and the results are subjective. As such, the results are not very accurate compared to other types of hardness tests.
Credible Hardness Testing Services in Malaysia
At Xpert Engineering, we strive to meet our clients’ essential hardness testing needs by providing various types of hardness tests. With our experienced workers and well-equipped testing lab, we have the capabilities to provide accurate hardness test results.