Spotting in 6061-T6
Spotting in 6061-T6
(OP)
We are experiencing spotting in turned 6061-T6 bar stock. The bar stock is turned and either anodized or polished with a high cosmetic requirement. In the past, our only resolution has been to use increasingly difficult to obtain "control grain" products (Alcoa's 6061-T6511X or Kaiser's 6061-T6511C for example). We have had some relief by using a minumum amount of etching on the anodized pieces, but this proves only slightly better.
I was hoping someone could comment on:
1) the possible alternatives to these products and/or
2) the wishful possibility of using a standard off-the-shelf 6061 product and somehow treating it to acheive a clearer finish in both anodized and polished situations.
Thanks in advance for any assistance you can give.
Steve
I was hoping someone could comment on:
1) the possible alternatives to these products and/or
2) the wishful possibility of using a standard off-the-shelf 6061 product and somehow treating it to acheive a clearer finish in both anodized and polished situations.
Thanks in advance for any assistance you can give.
Steve





RE: Spotting in 6061-T6
RE: Spotting in 6061-T6
RE: Spotting in 6061-T6
TVP, basically the parts are anodized as a customer requirement. The short answer is it's a price justification issue, the end customer is essentially paying more for high quality materials and our customer doesn't want to cover that up with just paint.
swall, I'm not exactly sure what you mean by rolled bar? If you are referring to a cold finished product, then yes I would suspect that it would have a much cleaner material than standard extruded, but the cost increase is significant.
RE: Spotting in 6061-T6
What is Your material spec??
Regards, Wil Taylor
RE: Spotting in 6061-T6
RE: Spotting in 6061-T6
6061-T6 is the alloy and temper.
6061-T6xxx can be procured per the following specifications [just a few listed].
AMS-QQ-A-250/11, AMS4025, AMS4027 [sheet/plate]
AMS-QQ-A-225/8, AMS4117, AMS4128 [rolled bar]
AMS-QQ-A-200/8, AMS4160, ASTM B308 [extruded bar & shapes]
AMS-WW-T-700/6, ASTM B429 [extruded tube/pipe]
Now… Seco1… what is the material spec Your 6061-T6 was procured per?
Note: there are may other "specs" for this material... with far fewer controls for grain size, cleanlieness, material properties, heat treatment, etc... such as "commercial or "architectural" grade material... that may be causing Your problem.
Regards, Wil Taylor
RE: Spotting in 6061-T6
So, preferable to order material per ASTM B211-03 Standard Specification for Aluminum and Aluminum-Alloy Bar, Rod, and Wire
-- rolled or cold-finished bar -- than per ASTM B221-05a Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes.
www.astm.org
Also, try different sources for extruded material; the stuff is normally pretty good.