indenteringsprov

Indenteringsprov, or indentation testing, is a method used to determine the hardness of a material by pressing a shaped indenter into its surface with a controlled force and measuring the resulting impression. The test is widely used because it is relatively simple, requires small samples, and can be applied to metals, ceramics, ceramics coatings, and thin films. Hardness values obtained from indentation tests are commonly used for material comparison, quality control, and to estimate related properties such as strength.

Several indenter geometries are standard in indentation testing. The Brinell test uses a hard steel or carbide ball and reports a Brinell hardness number. The Vickers test employs a diamond pyramid with a square cross-section, producing a Vickers hardness value. The Rockwell test uses a diamond cone or a steel ball and yields a Rockwell number on a local scale. Micro- and nanoindentation extend this approach to much smaller scales, using very light loads and sharp tips (such as Berkovich) to measure hardness and, by analyzing load-displacement curves, elastic modulus as well.

The procedure generally involves surface preparation, application of a load with a calibrated instrument, a dwell period, and measurement of the impression size or depth. Calculated hardness values are reported with corresponding indenter type and load (for Brinell, Vickers, and Rockwell) or from a curve (for nanoindentation). Standards bodies such as ISO and ASTM publish methods for different indenters and loading conditions.

Advantages include simplicity, small sample requirements, and applicability to a range of materials. Limitations involve surface finish, anisotropy, residual stress, and indentation size effects, which can influence accuracy and repeatability. Indenteringsprov remains a foundational tool in materials science and engineering.