P22 - Optimized hardness testing: Precise force application and measurement at low forces

Event
SMSI 2025
2025-05-06 - 2025-05-08
Nürnberg
Band
Poster
Chapter
Poster Session
Author(s)
T. Frank, S. Hermann, A. Grün, H. Wünscher - CiS Forschungsinstitut für Mikrosensorik GmbH, Erfurt (Germany), P. Beisel - KB Prüftechnik GmbH, Hochdorf-Assenheim (Germany)
Pages
275 - 276
DOI
10.5162/SMSI2025/P22
ISBN
978-3-910600-06-5
Price
free

Abstract

In hardness testing, an indenter is pressed into the workpiece with a defined force to determine its hardness. It is important that the force builds up without shocks or vibrations and without overshoots. The ideal test sequence comprises four phases: approach without force contact, continuous application of force, holding the test force and finally withdrawal. The precise implementation of the test force is particularly demanding with small forces and requires sensitive force measuring cells and controls. The time of contact is critical, as too fast approaches can distort the measurement. With small forces, the approach speed must therefore be reduced. Distance sensors are used for optimization. Improvements include sensitive Si strain gauges and a two-stage spring for the indenter.

Download