What kind of failure is this ?
Note that both trans-crystalline and intergranular cracks are present and that there is some evidence of cold work.
OK ... Peek now.
|
Here is another failure, this time in an aluminum brass
(copper - 21% zinc - 2.2% aluminum). It is a cooling tube from a
wind tunnel. The air temperature varied from 110F to 400F (43C to
203C) and chlorinated river water was inside the tube. What kind of failure is this ? Note that both trans-crystalline and intergranular cracks are present and that there is some evidence of cold work. OK ... Peek now. |
| This looks like stress corrosion
cracking coupled with mechanical fatigue. The high velocity air
passing the water-filled tubes caused the tubes to vibrate because of
vortex shedding. They should be braced more securely. |
| The
eighth specimen is an example of failure by plug
type dezincification. |