Preparation method for in situ tensile testing in transmission electron microscopy based on push-to-pull chip

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• In-situ mechanical characterization is vital for understanding micro- and nano-scale metallic materials.
• The Bruker Push-to-Pull (PTP) technique offers experimental flexibility but requires precise sample-chip bonding.
• Existing bonding methods face challenges due to the high displacement resolution of PTP testing.

Purpose of the Study:

• To develop a robust and controllable welding process for sample-chip attachment in PTP in-situ mechanical testing.
• To ensure reliable load transfer and maintain uniaxial tensile conditions during testing.
• To meet the stringent requirements for subsequent transmission electron microscopy (TEM) analysis.

Main Methods:

• Fabrication of contacts on the sample slice using a focused ion beam.
• Deposition of platinum pads on the PTP chip using a focused ion beam.
• Employing a high ion beam current to co-mingle contacts and pads for robust bonding.

Main Results:

• Achieved strong and reliable bonding between the specimen and the PTP chip.
• Ensured well-controlled uniaxial tensile load transfer from the actuator to the PTP structure.
• Created a sufficient thinning angle compatible with transmission electron microscopy (TEM) sample preparation.

Conclusions:

• The developed focused ion beam welding method provides a precise and efficient strategy for micro/nano-scale in-situ mechanical testing.
• This preparation technique enhances the reliability and applicability of PTP testing for advanced materials.
• The method facilitates detailed microstructural analysis via TEM after mechanical testing.