Aluminum Question...

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I am going to be tigging an intercooler together.. only I have no clue as to what grade the aluminum is.. and it has been tigged several times with different quality of welds..  I just want to make sure that I do not use their welds to base my material upon.  That being said, I have 1100 filler and 4300 series filler and 5600 series filler... ( not sure of the exact series of either one of those two ).   Just curious which filler you guys think would be best suited..  thanks
Reply:4043.But if it is gonna be annodized then 5356....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapster4043.But if it is gonna be annodized then 5356....zap!
Reply:And another vote...My name's not Jim....
Reply:zap is right on the money.
Reply:Note:Some aluminum alloys are considered non-weldable.  7075 is in that category.Although 4043 and 5356 are the 'main' aluminum filler alloys, and 5356 is usually called for if the base aluminum is weldable and will be anodized after welding (because 4043 turns grey/black when anodized), there may be a material property conflict if the service temperature of the part is greater than 150F.  The 5xxx aluminum alloys have a 150F service temperature limit because they are susceptible to stress corrosion cracking, this applies to filler material as well.  So if you somehow have a part that is supposed to be anodized but it has a service temperature greater than 150F, then you pretty much have to use 4043 filler and accept the possible color mismatch of the weld after anodizing (or make sure the part is color anodized to dark grey or black!    )Also watch out if you are trying to weld an unknown base alloy that has pre-existing welds with unknown filler alloys.  You really don't know what is what in that case.  And if something goes wrong with the part/assembly, since you were the last person to weld it then you are IT liability-wise.    The best laid schemes ... Gang oft agley ...
Reply:To add to the above post, which is completely correct, a good percentage of aluminum intercoolers are made from 3003, which should be welded with 1100 filler, not 4043 to prevent fatigue cracking. 4043 is NOT a do all filler by any means.
Reply:Originally Posted by makoman1860To add to the above post, which is completely correct, a good percentage of aluminum intercoolers are made from 3003, which should be welded with 1100 filler, not 4043 to prevent fatigue cracking. 4043 is NOT a do all filler by any means.
Reply:Originally Posted by 4sfedYes, but the intercoolers are brazed.  Most automotive intercooler manufacturers recommend using 4043 because it has a lower melting temperature and chemistry closer to the brazing alloy.
Reply:Originally Posted by makoman1860Well I would be careful of it. The interalloyed region of the weld will be aroud 2.5% silicon, and thats not a "happy" percentage. Without trying to jab at the aftermarket guys, for the most part I have found them to be less then experts on many subjects.
Reply:While the charts show higher strength with 4043 (good ones) will also show lower ductility for 4043. Lack of ductility (compared with other wires) often comes up with regards to fillet welds too, there's an article on Alcotecs site that goes into a little detail. Their filler selction chart rates alloys for weldability, strength, ductility, corrosion properties and colour match when anodizing4047 is a true brazing alloy, melting point is circa 1060F versus around 1200F for 1100Al and 4043 at around 1100F. Personally i would make filler choice based on the construction of the intercoolers tanks- many (in the UK at least) have cast end tanks so i would reach for 4043 in that instance. Fabricated end tanks and i (like most of the suppliers over here) use 1050 or 3103 (what you guys call 1100 and 3003 although 3103 is very slightly different) for the tanks, cores are going to be 1050 or 3103 so wire to use is 1050
Reply:Originally Posted by hotrodderWhile the charts show higher strength with 4043 (good ones) will also show lower ductility for 4043.
Reply:The isse with 4043 on 1100 has to do mostly with the trasition from 5% silicon to 0% silicon throughout the weld bead, and the effect of thermal growth and yes micro-cracking in applications that see temperature shifts ( i.e. intercoolers ). The reason you dont have this issue with brazing is that the bond is cohesive, and not interalloyed, so there is no inter-granular strain. All that being said, its not going to fail all at once and take someones head off, or maybe at all, however its just one of those little details we can pay attention to. Many times those little annoying cracks that keep popping up, are just the result of wrong material or joint configuration choice. 1100 does have much higher ductility than 4043, and your correct this may not directly affect fatigue life under non-plastic deformation loads, but how can we be sure some of our designs are not deforming as a part of normal life? Belt and suspenders ya know -Aaron
Reply:I don't have a link i'm afraid, the site isn't what it used to be and i can't be bothered to go searching for it. In hindsight it was probably comparing 4043 to 5356 anyway as i imagine most articles of this sort do so not really relevant here. IIRC both shear strength and ductility were the reasoning for selecting 5356 (provided it met other considerations)
Reply:Originally Posted by makoman1860 . . . but how can we be sure some of our designs are not deforming as a part of normal life?  Belt and suspenders ya know -Aaron
Reply:Originally Posted by 4sfedIntercoolers are always difficult . . . 30°F on one end and 300°F at the other, made of low-strength material with a high coefficient of expansion.  Since weight is a detriment to race cars and airplanes, I'd like to make the belt reliable enough that I can eliminate the suspenders.  Jim
Reply:Just to clarify a bit.. I put down the wrong numbers... it was 1100, 4043 and 5356...  but sadly, I had to leave and did not return till today.. only to find out.. someone else did... or should I say attempted it.. anyways... someone else bubble gummed it.. and it got sent out...  thanks for all the imput though guys...  you all rock  !!!
Reply:Originally Posted by smokeshowJust to clarify a bit.. I put down the wrong numbers... it was 1100, 4043 and 5356...  but sadly, I had to leave and did not return till today.. only to find out.. someone else did... or should I say attempted it.. anyways... someone else bubble gummed it.. and it got sent out...  thanks for all the imput though guys...  you all rock  !!!
Reply:Can anyone point me to a research article or additional detailed technical information regarding aluminum alloys (IE: with magnesium) degrading at high temperatures (IE: developing intergranular corrosion, or corrosion stress cracking, etc), such as what alcoa refers to as some alloys which are, or are not "Recommended for service at sustained temperatures above 150F" in their filler rod selection chart?  (I noticed that the ones not recommend generally seem to be the 5xxx series that have > 2.5% magnesium)Ideally, I'd like to see some studies, test results, or just more detailed technical information regarding how quickly and severely the degradation occurs with a wide variety of aluminum alloys, exposed to various temperatures for various durations of time or indicate any other important factors.Just want to learn more... thanks.
Reply:Check with the ASM(American Society for Metals).  I found a reference to a book:J.E. Hatch, "Aluminum Properties and Physical Metallurgy". 1984.in another text.  This book supposedly has information on precipitation hardening for several aluminum alloy systems, including the Aluminum-Magnesium-Silicon alloys that are being discussed here. Originally Posted by jakeruCan anyone point me to a research article or additional detailed technical information regarding aluminum alloys (IE: with magnesium) degrading at high temperatures (IE: developing intergranular corrosion, or corrosion stress cracking, etc), such as what alcoa refers to as some alloys which are, or are not "Recommended for service at sustained temperatures above 150F" in their filler rod selection chart?  (I noticed that the ones not recommend generally seem to be the 5xxx series that have > 2.5% magnesium)Ideally, I'd like to see some studies, test results, or just more detailed technical information regarding how quickly and severely the degradation occurs with a wide variety of aluminum alloys, exposed to various temperatures for various durations of time or indicate any other important factors.Just want to learn more... thanks.
Reply:Thanks much... wonder if my local library could get that book, or if I'd have to go to the engineering library of my local university.
Reply:Try this book for $10.00 from Lincoln.  IMO, the best $10.00 you will ever spend on a welding book:https://ssl.lincolnelectric.com/linc...sp?prodnum=MHW