| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Solidification in External Fields
|
| Presentation Title |
Structure and Properties of the Terrestrial vs. Microgravity Solders Under Extreme Conditions of Elevated and Cryo Temperatures |
| Author(s) |
Manish Kumar, Ralph Napolitano, Sid Pathak |
| On-Site Speaker (Planned) |
Manish Kumar |
| Abstract Scope |
We report results from the microstructural characterization and resultant micro-to-nano mechanical response of solders under extremes of 1) Earth’s gravity vs. microgravity (1g vs. ~1×10-5g), and 2) cryogenic and 3) elevated temperatures mimicking those experienced during space exploration missions (– 157ēC to +121ēC outside the International Space Station (ISS). Using 40wt%Pb-60wt%Sn solders from the ‘In-Space Soldering Investigation’ conducted onboard ISS, we demonstrate how temperature-induced density gradient and void-induced Marangoni convection during melting/solidification onboard ISS affect its microstructure and properties. Our microscopy and micro-tomography analysis demonstrates a considerable amount of internal porosity (5X terrestrial solder) and accumulation of voids and Pb-rich dendrites toward the high-temperature region in the microgravity solder.
Additionally, under cryogenic conditions we examine the effects of β-to-α phase transformation in Sn below 13ēC and the associated volume and internal stress changes in Sn-based solders, while the effects of accelerated aging effects are probed at elevated temperatures (up-to +120ēC). |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Joining, Solidification, Characterization |