What are the steps of microhardness test?

       In order to ensure the accurate measurement of coating hardness, the following steps should be followed:



    1) Sample preparation

    The test part of the tested sample should be properly pretreated to make the surface smooth and smooth, and cleaned to make the surface clean and free from dirt such as oil stains. When measuring the surface hardness, the sample should be prepared according to the metallographic thickness measurement method.

    2) Instrument inspection and calibration

    The microhardness tester should be strictly inspected and calibrated according to the product manual of the instrument to ensure that the instrument works normally, the indentation is clear, the measured value is accurate, and meets the standard hardness value range.

    3) Select load mass and loading speed

    Before actual operation, the load mass should be estimated according to the aforementioned formula according to the properties and thickness of the tested coating, and an appropriate loading speed should be selected, and a larger load and a smaller loading speed should be selected as far as possible.

    4) Loading

    Place the test part of the test sample under the objective lens of the hardness tester. After selecting the appropriate position of the indentation, move it slowly to the bottom of the diamond indenter of the hardness tester, and then load it evenly and slowly until the indicator light of the instrument indicates that the loading has been reached. Loading stops at the selected load, and the load is removed immediately.

    5) Observe the indentation

    Move the sample under the objective lens of the durometer, and the indentation of the square pyramid and the diagonal line of the indentation on the specimen can be clearly seen through the eyepiece of the durometer.

    6) Measure the indentation length

    Accurately measure the diagonal length of the indentation, and look up the hardness value according to this length.

    7) Repeat the operation

    For the same sample, the above steps shall be repeated for more than 5 times under the same conditions, and the average value shall be taken as the final measurement result of coating hardness.