Mikrokovuusmittaus

Mikrokovuusmittaus, or micro‑hardness testing, is a technique used to determine the hardness of small material samples, typically at a scale of a few hundred micrometres to a few millimetres. The method involves pressing a diamond indenter into the surface of a specimen under a precisely controlled load and then measuring the size of the indentation left when the load is removed. The hardness value is calculated using the indenter geometry and the applied load, giving a measure in units such as HV (Vickers hardness) or HK (Knoop hardness).

Common indenter shapes include the Vickers pyramidal tip, the Knoop diamond, and the spherical Brinell indenter. Each geometry offers advantages for specific applications: the Vickers indenter provides a square impression suitable for isotropic materials, while the elongated Knoop geometry is ideal for thin or highly anisotropic samples. The Brinell method, although semi‑microscopic, is still employed in some contexts where a ball indenter offers a more uniform strain field.

Micro‑hardness testing is widely employed in materials science, metallurgy, and quality control to assess properties such as wear resistance, brittleness, and the effects of heat treatment or alloying. It is also important in evaluating the mechanical performance of micro‑structures in advanced manufacturing, including additive manufacturing and micro‑electromechanical systems (MEMS). While the technique offers high spatial resolution, it requires careful sample preparation and calibration of the indenter to avoid errors. Overall, mikrokovuusmittaus remains a cornerstone method for characterizing mechanical hardness in a broad range of engineering and scientific materials.