Indentation diagonal measurement
The indentation diagonal measurement is an optical method for determining the two orthogonal diagonals of a Vickers indentation using a light microscope. This measurement is crucial for the accurate calculation of the hardness index.
Physical-chemical mechanism of action
The indentation diagonal measurement refers to the optical capture of the two perpendicular diagonals of a Vickers indentation. A Vickers indentation is a geometrically precise triangle that is created by the pressure of a heavy pyramid body in a metal piece. The measurement of these diagonals is carried out using a high-resolution light microscope.
Metallurgical relevance & risks in welding
The indentation diagonal measurement is crucial for the accurate calculation of the hardness index, which indicates how hard the metal is in the weld zone. An inaccurate measurement value can lead to incorrect hardness interpretations and thus to problems in quality assurance and the detection of cracks or hot cracks. It is important that the diagonals are measured accurately and orthogonally to each other to ensure a correct calculation of the hardness index.
Workshop practice & instructions
To perform the indentation diagonal measurement, a high-resolution light microscope is used. The Vickers indentation should appear clear and sharp in the microscope image. The two orthogonal diagonals are then measured and inserted into the formula for the hardness index. It is important that the measurements are carried out precisely and that the microscope is correctly calibrated. An inaccurate measurement can lead to wrong results and thus to misinterpretation of the metal hardness.