The Vickers hardness tester adopts diamond indenter, which is pressed into the surface of the sample under a certain test force. Unload test force after maintaining a specified time and measure the diagonal length of the indentation, then Vickers hardness value (HV) is calculated according to the formula.
The effect of the head pressing down
- Applying the test force: The head pressing down process is a key step to transfer the set test force (such as 1kgf, 10kgf, etc.) to the surface of the tested material through the indenter.
- Forming an indentation: The pressure makes the indenter to leave a clear diamond indentation on the material surface, and the hardness is calculated by measuring the diagonal length of the indentation.
This operation is widely used in hardness testing of metal materials, thin sheets, coatings, etc., because it has a wide test force range and small indentation, which is suitable for precision measurement.
As a common structure design of Vickers hardness tester (different from workbench rising type), the advantages of “head pressing down” are the rationality of operation logic and mechanical structure, details as follows,
1. More convenient operation, conform to human-machine habits
In the head pressing down design, the operator can directly place the sample on the fixed workbench, and complete the contact and loading of the indenter by head downward, without frequently adjusting the height of the workbench. This “top-down” operation logic is more suitable for conventional operation habits, especially friendly to novices, can reduce the tedious steps of sample placement and alignment, reduce human operation errors.
2. Stronger loading stability , higher measurement accuracy
The head pressing down structure usually adopts a more rigid loading mechanism (such as precision screw rods and guide rails). When applying the test force, the verticality and loading speed of the indenter are easier to control, which can effectively reduce mechanical vibration or offset. For precision materials such as thin sheets, coatings, and small parts, this stability can avoid indentation deformation caused by unstable loading and significantly improve measurement accuracy.
3. Wider adaptability of samples
For samples of larger size, irregular shape or heavier weight, the head-down design not require the workbench to bear excessive load or height restrictions (the workbench can be fixed), and only needs to ensure that the sample can be placed on the workbench, which is more “tolerant” to the sample. Rising workbench design may be limited by the load-bearing and lifting stroke of the workbench, so it is difficult to adapt to large or heavy samples.
4. Better measurement repeatability
The stable loading method and convenient operation process can reduce the error caused by human operation differences (such as alignment deviation when the workbench lift). When measuring the same sample multiple times, the contact state between the indenter and the samples is more consistent, the data repeatability is better, and the result reliability is higher.
In conclusion, the head-down Vickers hardness tester has more advantages in convenience, stability, and adaptability by optimizing the operation logic and mechanical structure, and is especially suitable for precision material testing, multi-type samples testing or high-frequency testing scenarios.
Post time: Jul-16-2025
