A356-T6 Al Casting S-N Curves 1

[Kristina Sornikova]

Dear all, if any of you experts know of material SN curves for A356 T6 Al alloy, preferably public aerospace sources, and multiple Kt curves, please post link. Thank you...

 

[WKTaylor]

KS... You have provided scanty/no information for most of us to assist You.

CAUTION: Assume this issues is for relatively 'new' castings. Castings that have been in-service for a long-while can be 'wild cards' due to and heavily 'weathering' [microscopic moisture intrusion] since older castings were rarely 'sealed' with out 'cause'.

What 'specifications' and what 'casting quality classification'?

Environmentally sealed or unsealed.

Do Your new castings come with cast-in metallurgical and mechanical test coupons... or... other features [thick pads] that allow recurrent testing ['each' or random/statistical, etc]?

Complexity of casting demands extra Knowledge. Starters.

Aerospace Structural Metals Handbook... Section Code 3105... 356.0 and A356.0 [castings]

AFWAL-TR-84-4117 Manufacturing Methods for Process Effects on Aluminum Casting Allowables

WL-TR-91-4111 Durability and Damage Tolerance of Aluminum Alloy Castings

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Kristina Sornikova]

Dear Wil,

Thank you for detailed response. I realize I did not put enough info now.

Let us say casting A356-T6, class 12, per MIL-A-21180. The problem is it is hard to find 'material' S-N curves for this material even similar one.

I am looking material S-N curves like in MMPDS. MMPDS has no A356 curves.

Our castings have detail notes on coupon testing etc. Just need to find S-N curves like in MMPDS for this casting.

 

[BrianE22]

Did you do a Google search on A356-t6 fatigue curve? There's a bunch of curves under "Images".

 

[Kristina Sornikova]

Thank you Brian, but looking for something official, formal.

 

[EdStainless]

MMPDS won't touch this since the scatter in fatigue with castings is so large.
For one producer, using one method, with their in house chemistry restrictions, and the correct NDT, will yield usable fatigue values.
Ultimately you will need to generate your own to confirm whatever you find out there.

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P.E. Metallurgy, consulting work welcomed

 

[Kristina Sornikova]

Thank you EdStainless..