Can ultrasound pass through metal?

[physea]

Hello

Can ultrasound pass through metal?
How much of it can pass and how thick the metal can be?

I couldn't find anything online, I only found some contradicting and unclear information.

 

[sophiecentaur]

Hello

Can ultrasound pass through metal?
How much of it can pass and how thick the metal can be?

I couldn't find anything online, I only found some contradicting and unclear information.

Ultrasound cleaning tanks are made of metal and the transducer is outside the (thin) metal skin.

 

[physea]

Ultrasound cleaning tanks are made of metal and the transducer is outside the (thin) metal skin.

I don't understand what you are saying

 

[berkeman]

I don't understand what you are saying

He is using the coupling method for those cleaning tanks as an existence proof that ultrasound energy can go through at least a thin layer of metal.

And if you couple it correctly to the metal, it can go quite far in metal. It's not all that difference from sound traveling in metal. I can hear a local commuter train (BART electric trains) coming from the sounds the tracks make long before the train shows up...

 

[nasu]

Attenuation of ultrasound in metals is much lower than in water (or soft biological tissue). Ultrasound nondestructive testing is used extensively for metal parts.
However the attenuation varies strongly with frequency. Ultrasound can range from tens of kHz to almost terahertz so to get an answer regrading how thick the metal and other details you should specify the application and the frequency range of the ultrasound.

 

[sophiecentaur]

Attenuation of ultrasound in metals is much lower than in water (or soft biological tissue). Ultrasound nondestructive testing is used extensively for metal parts.
However the attenuation varies strongly with frequency. Ultrasound can range from tens of kHz to almost terahertz so to get an answer regrading how thick the metal and other details you should specify the application and the frequency range of the ultrasound.

There is another issue here, though. The ultrasound energy has to be Matched at any interface. This is necessary between the source and the destination of the waves or very little energy will pass through into and out of the metal. Different transducers must be used for different applications - body tissue, metal, air etc.

 

[nasu]

The same type of coupling gel can be used for both industrial and medical applications. The medical one has some antiseptic components. A thin layer of water will work too. And the same transducer will work for both, in principle. In medical imaging they use arrays of transducers whereas in industrial nondestructive testing they can use both single transducers and arrays.
The air coupled ones are indeed of a different design. But the question was not about ultrasound going through air.