YouTuber DaveHax had some gallium lying around, so he wanted to see the chemical reaction when it was applied to an aluminum tennis racket.
Spoiler: "The gallium invades the aluminium to form a fragile and brittle material, and the tension in the racket ripped it apart!"
Bonus: Here's what happens on an aluminum can:
• Incredible – Gallium Vs Aluminium Tennis Racket (YouTube / DaveHax)