GB/T 39815-2021Test method for scratch resistance of ultrathin glass (English PDF)

3.1 Furrowscratch

Visible V-shaped damage marks formed on the surface of the sample.

3.2 Criticalload

The normal load applied when plow-shaped scratches with continuous length greater than 3mm begin to appear on the surface of the sample.

3.3 Scratch resistance

The ability of the surface of the sample to resist being scratched by hard objects is expressed by the critical load value.

3.4 Constantloading

The load acts on the measured object at a constant value.

3.5 Continuousloading

The load starts from a certain initial value and is applied to the object under test in a continuous increment manner.

7.1 Test environment

The test should be carried out at room temperature and relative humidity (50±20)%.

7.2 Sample handling

Before the test, use a soft cloth and cleaning agent to remove the dust, oil and other impurities on the surface of the sample that may affect the test result, and rinse with distilled water Wash it and place it for at least 4h under the environmental conditions specified in 7.1. Do not damage the surface of the sample during sample handling.

7.3 Test procedure

7.3.1 Constant loading method

The test should be carried out according to the following steps.

a) Turn on and check the instrument;

b) Adjust the sample stage to a horizontal state;

c) Set equipment parameters. moving system speed (60.0±1.0) mm/min;

d) Place the sample on the sample table and in close contact with it, the sample should be properly fixed, and the sample should not be between the sample table and the sample table during the test. Relative slip should occur;

e) Adjust the position of the indenter of the scratcher so that the angle between the axis of the indenter and the plane of the sample table is (90±2)°;

f) Adjust the lifting device, set the initial pressure value of the indenter, such as 5N, turn on the moving system, and the indenter will continuously move on the glass surface to form (100.0±5.0)mm scratches, and the scratch line should be parallel to the long side of the sample. Use the camera system to observe whether the surface of the sample is There are plough-shaped scratches with a continuous length greater than or equal to 3mm;

g) If there is no plough-shaped scratch with a continuous length greater than or equal to 3mm in the test according to 7.3.1f), you can submit it according to the needs of the test.

Increase the force, such as increasing 0.5N or 1N, continue to test according to 7.3.1f) steps, until the continuous length is greater than or etc.

Plow-shaped scratches of 3mm. During the test, all the scratch lines should be parallel to each other, and the interval b should not be less than 5mm.

The layout diagram is shown in Figure 3, and the scratch line should not be less than 10mm from the edge of the sample;

h) If a plough-shaped scratch with a continuous length greater than or equal to 3mm is found in the test according to step 7.3.1f), it can be reduced according to the needs of the test.

Use force, such as decrement 0.5N or 1.0N, continue to test according to 7.3.1f), until there is no continuous length greater than or equal to 3mm plow-like scratches.

Note 1.Select the indenter force corresponding to the length of the continuous plough scratches closest to 3.0mm as the critical load value of the scratch resistance of the sample.

Note 2.If the plough-shaped scratches that meet the conditions are not obtained on the surface of the sample, the test of the sample will fail and be invalid, and another sample will be taken to restart the test, and at the same time according to For the test results of the upper sample, increase or decrease the initial pressure value of the indenter as appropriate.

Note 3.If the sample is cracked or broken in the middle, the test of the sample fails and becomes invalid.

7.3.2 Continuous loading method

The test should be carried out according to the following steps.

a) Adjust the instrument and fix the sample according to the steps in 7.3.1a) to e);

b) Adjust the lifting device so that the initial pressure value of the indenter is (0.2±0.1) N, turn on the moving system, and the indenter continuously moves on the surface of the sample.

The scratch line is parallel to the long side of the sample, and the pressure loading rate is 12.0N/min~24.0N/min, preferably 18.0N/min, moving The system speed is (60.0±1.0)mm/min, and it stops moving when the length of the plow-shaped scratch exceeds 4mm. Test 5 times in a row, each time The scratch lines are parallel and the spacing is not less than 5mm, and the distance between the scratch lines and the edge of the sample should not be less than 10mm;

c) According to the video of the indenter and the scratch on the glass surface recorded by the camera system, read the measurement when the scratch length is (3.0±0.5) mm The test pressure value is used as the test result, and the arithmetic average of the 5 test results is taken as the critical load of the scratch resistance of the sample. Charge value.