Official Liquidmetal Ball Bouncer Demonstration. This video shows the amazing coefficient of restitution of Liquidmetal Technologies bulk metallic glass alloys. The balls are made of stainless steel, while the plates on which the ball bearings bounce are made of three different materials as indicated. The Liquidmetal plate transfers almost all the kinetic energy of the falling ball back into the ball instead of absorbing that energy into itself by yielding. The very high coefficient of restitution of liquidmetal has given it a clear advantage over other materials in applications such as golf clubs.