When we mention the hardness tester, many of us may be unfamiliar with it. We don't know what it is. It is widely used to measure the microhardness of micro and thin specimens, surface coating and other specimens, and to determine the Knoop hardness of brittle and hard materials such as glass, ceramics, agate and artificial gems. It is an ideal hardness testing instrument for research and testing of materials in scientific research institutions, factories and quality supervision departments. However, its basic principle is not very clear, so the working principle of Vickers hardness tester is briefly introduced. Let's understand it together!
Principle of Vickers hardness tester:
Under the load of 49.03 ~ 980.7n, the square cone-shaped diamond with a relative angle of 136 ° is pressed into the surface of the pressing material, and the diagonal length of the indentation is measured after the specified time, and the hardness is calculated by the combustible gas detector according to the formula. It is suitable for hardness measurement of larger workpieces and deeper surface layers. The Vickers hardness has small load Vickers hardness test load of 1.961 ~ < 49.03n. It is suitable for the hardness measurement of thin workpiece, tool surface or coating; the micro Vickers hardness test load is less than 1.961n, and the anemometer is suitable for the hardness measurement of metal foil and extremely thin surface layer. HV - suitable for microscopic analysis. Vickers hardness (HV) is the conversion of Vickers hardness (HV) when the load is less than 120kg and the diamond square cone impactor with a top angle of 136 ° is pressed into the material surface, and the surface product of indentation pits is divided by the load value, which is the conversion of Vickers hardness value (HV).
Working principle of Vickers hardness tester
The expression method of Vickers hardness is as follows:
Vickers hardness is expressed as HV Vickers hardness symbol. The value in front of HV is the hardness value, and the following is the test force value. The standard test holding time is 10 ~ 15s. If the selected time is beyond this range, the holding time should be noted after the force value. For example:
600hv30 - indicates that the hardness value is 600 when 294.2n (30kg) test force is used for 10-15s.
600hv30 / 20 - indicates that the hardness value is 600 with 294.2n (30kg) holding time of 20s.
The above introduction is about the working principle of Vickers hardness tester, in use, we must understand clearly, so as to facilitate better use.