Correlate Mechanical Testing with STEM/EBSD

The FT-NMT04, from Femtotools has been specifically produced for research into the stress-strain response of materials through both the observation of events on the material’s surface and data from EBSD, STEM and TKD to provide an unprecedented level of quantitative information on dislocation and phase transformation mechanisms.

The instrument can be used to carry out pillar compression, micro-tensile and cantilever bending tests alongside EBSD for the observation and quantification of dynamic material parameters such as localized strain behavior and dynamic phase transformations.

The micro-tensile testing of thin films and other electron-transparent samples can be carried out alongside STEM and TKD measurement to further probe a material’s plasticity at the dislocation scale. Firstly, a location of interest is selected using information on the sample’s crystal orientation and microstructure gathered using EBSD and SEM. Following this a FIB is used to remove a sample segment, which can then be held on a testing sample support, e.g. the Nano-Tensile Testing Chip from Femtotools, and secured using electron or ion beam induced deposition.

The sample segment is then carved and thinned down to electron transparency using a low voltage FIB, which helps avoid sample damage, for the following STEM imaging. Linear elasticity is observed during the loading of the sample followed by a plastic regime, which has several load drop events, before the final fracture of the sample.

The FT-NMT04’s extremely high displacement and load resolution, true displacement control and rapid data collection make it possible to analyze the lifetime and magnitude of individual load drops. When this data is combined with STEM imaging it is possible to determine the characteristic load (at a resolution below 0.5 µN) related to specific plastic events. This allows specific dislocation interactions involving lattice defects to be studied, for example the shearing of precipitates from full or partial dislocations, or Orowan bowing.

Micro-tensile testing using the FT-NMT04 allows a statistical understanding of localized plastic mechanisms to be developed down to the dislocation scale.

This information has been sourced, reviewed and adapted from materials provided by FemtoTools AG.

For more information on this source, please visit FemtoTools AG.