Evaluation of Measurement Uncertainty of Vickers Hardness Test of Metal Materials

The measurement uncertainty of metal material Vickers hardness test mainly results from test force, standard hardness block, measurement of indentation diagonal length, hardness tester itself, test result rounding off, etc. According to the requirements for hardness testers and standard hardness blocks in GB/T 4340.1-2009, combined with the production practice, the measurement uncertainty of Vickers hardness test with several different test forces was calculated. The results show that the measurement uncertainty derived from the maximum permissible error of the hardness tester was the largest. For the same Vickers hardness, the larger the test force was, the smaller measurement uncertainty of Vickers hardness test was. Therefore, in daily testing, under the premise of meeting the requirements, the test force should be chosen as large as possible to reduce the measurement uncertainty and make the test results more accurate and reliable.