VickersHärte

Vickers Härte, or Vickers hardness (HV), is a material property that characterizes resistance to plastic deformation. It is determined by pressing a diamond indenter, shaped as a square-based pyramid with an apex angle of 136 degrees, into the material surface under a defined load and dwell time. After indentation, the diagonals of the resulting square impression are measured, and the mean diagonal is used to determine hardness.

The Vickers hardness number HV is defined by the equation HV = 1.8544 F / d^2, where F is the applied load in kilogram-force (kgf) and d is the mean diagonal of the indentation in millimeters. The unit HV corresponds to kgf per square millimeter, and can be converted to megapascals by multiplying by approximately 9.807. The method applies across a wide range of loads, giving HV values such as HV0.01, HV0.1, up to HV100 in macro-scale testing. The indentation geometry allows comparisons across materials with different elastic responses.

Procedure and interpretation: A well-prepared surface is required, with a typical dwell time of 10–15 seconds. The diagonals of the indentation are measured with optical means, and at least two indentations (often four) are averaged to obtain HV. The technique is sensitive to the indentation size effect, surface finish, and measurement accuracy, and results are reported together with the load used.

Applications and standards: The Vickers test is widely used for metals and some ceramics and composites, providing a common hardness metric for comparing materials and heat-treated states. Standards include ISO 6507 and ASTM E384, with microhardness variants such as HV0.01 and HV0.1 used for thin or hard coatings. In German-language contexts, it is referred to as Vickers Härte.