New technique to measure the mechanical quality factor of metals using spherical samples

We developed a new technique for measuring the mechanical quality factor of metals from room temperature down to . Spherical resonators with a diameter of were suspended from the center with a copper rod. Since a sphere has a large number of resonant modes it is always possible to find some which are practically unaffected by the suspension and it can be assumed they are representative of the 'intrinsic' values. With this method we measured a Q-factor of 120 million in Al5056, the highest published value for a metal.