The systematic development of advanced steel alloys requires a systematic understanding of their complex heterogeneous microstructure and their properties. Furthermore, the overall performance of these steels is defined by the volume fraction of each constituent and their properties. For this reason, it is crucial to understand the fracture behavior of each constituted and its interfaces in order to predict the fracture behavior of the material. Fracture testing of FIB-machined microcantilevers that are pre-notched at a well-defined locations enable the direct quantification of the fracture toughness, yield strengths and elastic properties of a material (and its interfaces).
Application Example: Micro- and Nano-Scale Chevron Notch Fracture Test
In the depicted work by Prof. Mortensen (Laboratory of Mechanical Metallurgy, EPFL, Switzerland) microcantilevers with a chevron notch are fracture tested with the FT-NMT03 Nanomechanical Testing System. For this purpose, the tip of the FT-S Microforce Sensing Probe is first aligned to the microcantilever. Then, a compression test with a continuous forward motion is started while recoding the applied force and the deflection of the cantilever at a high sampling rate.
Application Example: Fracture Testing of Hollow Microbubbles
The systematic development of new, lightweight, high-strength materials requires the accurate investigation of their mechanical properties. The depicted work by Prof. Daniel S. Gianola from UC Santa Barbara demonstrates the incorporation of stiff, hollow microparticles (bubbles) into a polymeric matrix. For the development of such lightweight materials, tailoring the mechanical properties of the hollow microparticles is crucial. Using in-situ SEM nanomechanical testing, Prof Gianola demonstrated that thermal treatment of these nanoparticle-shelled bubbles will result in an enhancement of the stiffness and strength by a factor up to 14.