|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Metal-Matrix Composites: Advances in Processing, Characterization, Performance and Analysis
||In Situ Study of Spontaneous Nanocrystallization of Intermetallics for Interconnection of High-power Electronics
||Ying Zhong, Chunqing Wang
|On-Site Speaker (Planned)
A new phase-transformation-induced path to spontaneous formation of extreme nanograin structure will be presented. In-situ-heating-mode-microscopy exhibited a substantial grain-growth of Cu6Sn5. During cooling, the grain-growth continued, but it spontaneously switched to grain-refinement mode on phase transformation through ~180 °C from η-Cu6Sn5 to η’-Cu6Sn5, ending up with an extremely small nanograin size of ~2.5 nm. The cooling cycling always restores the nanograin size regardless of thermal exposure history, making this to be the first demonstration to stabilize the nanograin with its own spontaneous behavior. The Young’s Modulus was significantly reduced by ~×3, and the elongation was remarkably increased by ~×8 to ~9%. In this presentation, we will discuss the cooling and phase transformation at atomic level and reveal a new path to manufacture and stabilize extremely refined sub-4 nm grains by taking advantage of the spontaneous phase transformation behavior.
||Electronic Materials, Solidification, Joining