vibration damping

Unobtanium.

Now, in the real world there are constraints. If you supply a hint or two about yours, more reasonable responses can be made. There are situations where solid lead metal is a decent vibration damping material, and others where compacted cotton is better, and sometimes you just want a shock absorber or a vibration isolation mounting.

So what kind of vibration do you want to damp? In what environment? Any constraints on cost, size, weight or compatibility with other materials? Hmmm?

It's somewhat redundant to say that a material should be lossy to be a good damping material. Metals are therefore among the worst, and rubber is among the best. Rubber is widely used for engine and transmission mounts in cars.

I've heard of asphalt being used, applied to sheet metal in a car body. Cork is often used for making sound-proof walls for recording studios.

Look at

Kuraray has some block copolymers they recommend for vibration damping and I think you'll find some discussion on their web site about the need for the Tg (that is, tan delta peak) near the temperature where you want the damping. They have a neat demo where they take two seeminly identical rubber balls, about the size of marbles, and drop them on a table from a height of about two feet. One ball will bounce high as you'd expect, but the other lands with a thud and doesn't bounce at all.

Polyisobutylene, butyl rubber, has no bounce at all. All the free space is crammed with sidechains. That also blocks gas diffusion, hence its use as inner tubes. Add high loss layers with horribly impedance mis-matched interfaces like dry sand.

One nice demo is a handball that is molded one hemisphere bouncy rubber or Super Ball and the other butyl rubber, both back. Wanging the thing on a hard floor shoots it high and it bounces until it hits the other side. Then, "thud" and nothing.

Oh LORD !!

Lord vibration isolators at

One of the large commercial manufacturers of vibration isolating components (usually elastomers and viscoelastomers).

Lord and other vibration control companies usually have some tutorial information on their web sites and in their catalogs to educate potential users.

Educating potential users by web or catalog is a lot cheaper than trying to educate alleged customer by telephone. It is a lot less tiring on the mind.

Oh LORD !!!!