The imprinting process according to
DIN SPEC 4864
0.2% proof stress Rp0.2 and tensile strength Rm from test indentations
The indentation method according to DIN SPEC 4864 opens up new applications in the field of materials testing. The comparative tensile strength RIm and comparative proof stressRIp0.2 to the tensile test can be tested quickly and easily. In addition, the local yield curve as a measurement result provides more information than the classic hardness conversion to tensile strength according to DIN EN ISO 18265.
The basic idea of the indentation method is to obtain material properties by matching FEM simulations to real measured data. The advantage is that input and output data are known for FEM simulation. If simulation and experiment match, the material properties can be taken from the simulation.
Sequence of the test procedure
- Hardness impression is placed force-controlled in a sample and subsequently measured three-dimensionally.
- FEM simulations with the same boundary conditions (force, application time, test specimen) are varied until the geometry of the simulation matches the geometry of the 3D measurement.
- The procedure converges when sufficient agreement between simulation and experiment is achieved.
- The material parameters are taken from the simulation, which agrees with the experiment.