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Material or a device changing its shape under pressure

Material or a device changing its shape under pressure

Material or a device changing its shape under pressure

Hi there,
I'm looking for some solid material that can change its shape or geometry under pressure. Let's say i have a solid piece of a sample with a diameter 10mm and length 100mm. The sample is placed in a pressure chamber and pressurised from 0 to 2000bar. Every 50bar the sample is being shrinked linearly 1mm in length. When the pressure is bleed off the sample comes back in its original length of 100mm.

Thanks for advance.

RE: Material or a device changing its shape under pressure

I don't know how "Solid" you want the material to be but there is a closed cell foamed aluminum product that maybe worth looking in to.
I think one of it main uses is for crush zones in cars but it may be able to spring back like a sponge.

RE: Material or a device changing its shape under pressure

Thanks for your suggestion, I'll definitely look at it.

RE: Material or a device changing its shape under pressure

The OP has just described a very specific type of pressure gauge. If you took a standard Bourdon type gauge and attached it to a sealed pipe that was pressurized to 200 bar with nitrogen, it would basically behave as described. Place this assembly in in the pressure chamber and the needle will move with chamber pressure. A pressure gauge designed like a stick-type tire-pressure gauge would be closer to what you say you want. This would be similar to a gas spring.

This cannot be done with a "material". Aluminum foam is not elastic. It can be done with a carefully designed device, provided you specifications are not unreasonable.

A stiff metal bellows with the correct spring constant, containing a vacuum, would do it.

RE: Material or a device changing its shape under pressure

We were looked at the Bourdon tube pressure gauges. It would be a perfect solution but we are limited by the space we have. I attached the drawing we prepared for a spring manufacturers. We basically want to see on other solutions to replace that spring. We looked at the helical bourdon tube design but couldn't find a supplier who are capable to make such a small helical tube to withstand 30ksi pressure.

RE: Material or a device changing its shape under pressure

Use stacked bellville springs. Use a small diameter piston rod so that pressure acts on a smaller area and the piston compresses the springs. You could use gas pressure rather than a spring, but then temperature will affect calibration.

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