|About this Abstract
|2023 TMS Annual Meeting & Exhibition
|Advances in Titanium Technology
|Phase Transformation Behavior during Ultrasonic Welding of Pure Ti Sheets with Fe Interlayer
|Syronn Francisco, Kuan-Chieh Hu, Jheyu Lin
|On-Site Speaker (Planned)
This study investigated the feasibility of joint production between commercially pure Ti sheets (Grade 2) by using ultrasonic welding (USW), a solid-state bonding process. Lap shear test evaluating joint strength and microstructural characterization using electron microscopy techniques exhibited that joints without interlayers are challenging to be ultrasonically welded. Fracture observation revealed that brittle fracture was the main feature and could be attributed to lower deformation of alpha-Ti. Comparatively, Ti sheets with a thin Fe interlayer sputtered on the bonding interface were successfully joined. This could be attributed to frictional heat and severe plastic deformation applied by static load and high-frequency oscillation during USW. And such heat-deformation interactions could facilitate Fe diffusion into the Ti matrix, leading to phase transformation from alpha-Ti (hexagonal close-packed) to beta-Ti (body-centered cubic) with improved deformability to form an integrated bonding interface.
|Joining, Titanium, Phase Transformations