A356 properties at < -200F

[UCengno1]

We have a cast aluminum exhaust for a pneumatic turbine device. What would be the repercussions if it was exposed to < -200 F exhaust for an extended period? There is no cryogenic property information readily avaiable on aluminum. That should be an obvious sign. Thanks.

BCK

 

[metengr]

Information regarding low temperature toughness;

Low-Temperature Toughness. Aluminum alloys represent a very important class of structural metals for subzero-temperature applications. Aluminum and aluminum alloys have face-centered-cubic (fcc) crystal structures. Most fcc metals retain good ductility at subzero temperatures. Aluminum can be strengthened by alloying and heat treatment while still retaining good ductility along with adequate toughness at subzero temperatures.

The fracture toughness data I reviewed was not a concern. However, there are other issues related to corrosion (?)and fatigue crack initiation and propagation in this type of service application. If the above concerns are addressed by proper design, I see no other problems.

 

[CoryPad]

Since 356 is an Al-Si two-phase casting alloy, it doesn't have great toughness to begin with. The Al phase does well with low temperature, but you still have the brittle Si phase that is the controlling item with fracture.

Regards,

Cory

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