Micro Vickers hardness tester

1、 Preparation before operation

1. Equipment inspection

   • Confirm that the power connection of the hardness tester is normal, and that all components (such as the indenter, stage, optical system, etc.) are not loose or damaged.

   • Clean the stage and sample surface to ensure no oil stains, dust, or impurities, and avoid affecting measurement accuracy.

2. sample preparation

   • The surface of the sample needs to be ground flat and polished to form a smooth plane (roughness usually ≤ 0.8 μ m), and the thickness should be sufficient to support the indentation depth (generally not less than 1.5 times the diagonal length of the indentation).

   • For irregular samples, fixtures can be used to secure them and ensure stability during testing.

3. Parameter Settings

   • Select the appropriate test force based on the sample material and testing requirements (common range: 10gf~1000gf, which needs to be adjusted through weights or electronic loading systems).

   • Set the holding time (usually 10-15 seconds, soft materials can be appropriately extended).

2、 Operation steps

1. Install the indenter and objective lens

   • Install the Vickers indenter into the spindle hole, ensuring a secure installation; Simultaneously install lenses with appropriate magnifications (such as 10x and 40x lenses, for observing indentation).

2. Sample placement and focusing

   • Place the sample on the stage and manually or electrically move the stage to move the sample testing site directly below the pressure head.

   • Switch to a low magnification objective (such as 10x) and adjust the coarse focus and fine focus knobs to achieve clear imaging of the sample surface (be careful not to touch the sample with the indenter).

3. Select test points and load

   • Select the test point position by moving the handle or software interface on the stage.

   • Activate the test force loading button, and the hardness tester will automatically apply the selected test force and maintain it for the set time, followed by automatic unloading.

4. Indentation measurement

   • Switch to high magnification objective lens (such as 40x), adjust the focal length to make the indentation edge clearly visible.

   • Use the built-in measurement system of the hardness tester (such as a crosshair sight or image analysis software) to measure the diagonal length of the indentation (two diagonals need to be measured and averaged).

5. Hardness value calculation

   • F is the test force (unit: N), which needs to be converted based on the actual loading force (e.g. 1kgf ≈ 9.807N);

   • D is the average diagonal value of the indentation (unit: mm);

   • α is the angle between the diamond pyramid and the indenter (standard value 136 °).

   • Calculate the Vickers hardness value (HV) according to the formula: HV=d22Fsin (α/2)=d21.854F
     among which

   • Some hardness testers can automatically calculate and display hardness values without the need for manual calculation.

6. Record and save data

   • Record the testing conditions (test force, holding time, objective magnification, etc.) and hardness values, and if necessary, save the indentation images for traceability.