TIG Welding 7075 Aluminum - Who Said You Can't?!?
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- เผยแพร่เมื่อ 3 ก.พ. 2025
- Ron Covell's filler rod holder video: • Ron Covell's Welding R...
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Thanks for watching
Aaron - I have always heard that 7075 is not weldable, because zinc is the primary alloying material. Your tests seem to bear that out. I have also heard that some high-end bicycles are made from aluminum in the 7000 series, so apparently there are some alloys that can be welded.
Pretty fascinating to see how you went about testing the possibilities. Maybe you could do something similar with 2024, which is a copper-based alloy - also not recommended for welding.
Thanks for mentioning my welding rod holder. It has really helped me keep my filler metal organized!
cheap mountianbike frames are 7005, the material has very little flex and they are harsh to ride.
Ron, 7075 is 1.2-2% copper…6% zinc, 2.2% magnesium, developed by Sumitoma in Japan for the Zero fighter inWWII…Alcoa reversed engineered in 1943
Ron , I know nothing about the processes. But I do know that some bikes are brazed and not welded. Would brazing be the reason 7000 series is used? or when 7000 series is used, brazing is the best technique to use?
I worked for a rather large blowmolding company, Whose molds were all made of 7075 T651. The rumor about "not weldable" flourished to some extent in the early years. I was a toolmaker, and did not need to do any welding, so I can not speak from hands on experience. Most of their welding of 7075 was done along edges and repair, rather than fabrication, but the results were solid and usable.
Some bike frames are glued into brackets. No welding.
I’m certified to weld on Aircraft and I was told that 2024 and 7075 are not weldable because the alloying metals separate when heated to melting temperatures. That’s probably why the aluminum brazing worked. Unfortunately a majority of aircraft use those two aluminum alloys. Made for a great video though. Keep up the good work.
That is why they Rivet most the plane.
Yes, especially 2xxx series as the allowing metal is copper. Cracking is almost impossible to avoid. However, I really haven't heard 7xxx series being like that. Maybe a delayed crack? But honestly, I'm not familiar with 7xxx series.
@@ZAPATTUBE Riveting makes manufacturing and maintenance easier and cheaper.
Yeah you can weld basically any alloys. Wether it is the same alloy after is a different thing
@@thomasbecker9676 That and anyone can rivet with very little training.
I had also heard that 7075 was classified by the American Welding Institute as "Un-weldable", so I won't do it either. You tried everything you had and couldn't get a Strong weld except with the "Solder" method, so I would say that you "proved a point". Thankyou.
It's really brazing, rather than soldering. Not sure why he said "soldering".
That ‘low temp aluminum brazing rod’ is no joke. In the right application it works very well.
7075 is super strong and machines awesome. Never tried welding it before and now I never will! Thanks for sharing.
How is it super strong if it snaps when you bend it
There’s a lot more to material science than “strong means no break when bend”
@@sammyd7857It's stronger than titanium. If you work with aerospace at all, many parts are made of 7075.
@@sammyd7857 Most likely its used thick and has a high hardness rating for aluminum.
@@MikeYurbasovich 7075 is very strong .
I learn something new every time I watch your videos!
👍
Thanks for taking a hit for the team. With my welding skills I don"t think I will step out of comfort zone of easily weldible materials. 😂
I honestly had no idea about the issues with 7075, or that the Alumiweld rod was actually useful. So thank you for this!
I did read an article about 4 years ago a rod was developed for 7075 that used some nano technology with titanium in the rod, it was real expensive. The article said it was a big deal because auto manufacturers could start using 7075 in cars more. The article even showed how it wasn't the prettiest looking weld but was structural sound.
Pretty sure I read the same article that you are referring to.
Heard that one could use spot-welding, e.g. electric resistance welding.
Really enjoyed this one! It helps us beginners to see that sometimes, it just can't be done. If I had have seen that crack appear on my bench the way I saw it appear in the video I would have automatically assumed I had done something wrong.
Thanks for trying anyway great stuff. I work with these materials alot, the appropriate "glue" does the job if you have enough surface area. The bike frames do give up on the welds, sometimes you can weld it to a forged or cast piece and mig it. We mainly use 6082, not as strong 7075 but better than 6061. Thanks again your videos are the real world stuff.
Very helpful real world testing. Everything I have read almost impossible to weld 7075. Thanks for testing.
Great video Aaron I learned a lot
The more informative the video you make the more I like it
Thank you
Thanks fo the demo👍🏻👍🏻👍🏻
And oh dear am I thankful for the effort you put in these vids
Been on your channel for years and only last night I had my first go at tig welding as I bought my first machine
The learning curve is more like a brickwall😅😅😅
Thank you thank you thank you
This was very interesting and helpful. Illustrates the temperament of metal to heat. Thanks.
I don't ever take on aluminum projects, I far prefer playing with steal. But I find these videos interesting, and sometimes I learn something that applies to steel fab. Thank you for all your work!
Before I had a tig, I used the alumiweld rods on a couple 6061 projects with a propane torch. Not ideal but for their intended strength it worked out good. It would be better with oxy-fuel torches so you can dial the o2 down a little to prevent the aluminum from oxidizing. With an AC tig they should also work pretty well when you don't need ultimate strength, just decent strength. My kit came with special flux, so it was a lot like soldering or brazing.
Thanks I love your videos. Been watching for many years. I really like your approach to your projects
Thanks for the video. It was educational to see how you approached learning what worked or didn't on this alloy.
I welded a 7075 80% AR lower after an end mill made a nice slot in the side of it (forgot to set the tool diameter in the mill). Works totally fine when it's a cosmetic fix, but no good if you need strength.
The fact that you are still using and praising the primeweld machines makes me confident in my decision to buy their products. I also find it so funny how many people have shit on primeweld because of the price. Your videos prove the results you get are not machine price related.
Entertaining and useful for those who did not know. My friends and I tried that some 30 years ago with the same results. It was a fun exercise though.
This channel is very helpful to a newbie, thanks Aaron
Thanks for sharing these test results. I recently did a similar test with 2024. The results were identical.
Love all your videos.
As always great content and something I've been told you don't do but never actually tried to see why
Very educational thanks.
We don't weld Aluminum where I work, but, I can tell you a story about a "know it all" welder who welded 5140 without any preheating and them threw the welded assemblies into a cold stillage. Wasn't long before the welds were all failing due to underbead cracking (very high HAZ hardness in parent metal - about Hv550). Cost us a lot of money to repair his fvck up, and the loss of reputation cost us even more.
The alloy components of 7075 include zinc, magnesium, and copper (in addition to the aluminum of course). I believe the copper may tend to glob together when molten instead of staying in solution, and you end up with a slurry of copper solids (higher melting point) in the remaining liquid over a wide temperature range as it cools (and shrinks). Aside from the obvious change in the grain structure of the alloy, the liquid has zero strength as the solids contract while cooling, and you get inevitable cracking in the microscopic gaps that grows quite large in the final pool. I think the reason the tacks worked was that there was a large molten pool available to feed the thermal contraction from the side.
I have a trials bike frame Planet X Zebdi, that is made of 7075 T6. It is welded, survived lots of bashing and it's still in one piece. So there is some method to do it.
Probably tig brazed with silicon bronze. Thats not a weld.
Thanks mate that was quite informative.
This is really interesting. Appreciate vids like this
Regarding the tack welds holding at the beginning, I would guess that this is a combination of the corners of the plate burning off and feeding the weld puddle a bit more, combined with the cooling weld puddle being able to shrink back from the open end of the joint as it cools, rather than just pulling directly on both sides and sinking in from the top. Less stress, less thinning.
As for other 7000 series aluminums, the internet says "The exceptions are 7003, 7005, and 7039, which are readily weldable with 5356 fillers." and I'm sure we can trust that since when has anyone ever said something incorrect on the internet?
Sounds like the plot for the next video! 😅
There are a few other 7xxx alloys that are weldable. 7024 is one as well.
I've been told this is why you shouldn't weld riveted ladders? great vid as usual!
Probably. If there are rivets or bolts in aluminum, there’s usually a reason
This man is a hero
Excellent work, always wondered about 7075, thanks
Learned this lesson the hard way...before Go Pro! Thank you for the validation. 😂
Great info. Thanks for video. Most talk able 7xxx issues, love the "do it" and see.
7075 is a mix of aluminum, zinc, magnesium and copper. Makes for a high strength aluminum that is more for cast parts than fabricated parts. Im with you on just dont bother trying to weld it as its going to fail. It becomes brittle along the weld joint or just cracks.
That explains why the brazing rod actually worked the best.. It is basically a zinc alloy solder... Any solder for Zamak or "pot metal" would likely also work reasonably for 7000 series if you absolutely had to...
Super informative…thank you Aaron for the time and expense to make this video…Paulie Brown
Interesting video and demonstration. Good info here, thanks!
Great tests, I always enjoy your approach to a challenge
I worked in massena when the extrusion part was alcoa I worked also in the re-melt where it was alloyed there is a lot of zinc in it.
Respect from West Texas
JB weld, duct tape, super glue, or bailing wire. Got it. 7075 here I come.
Very good..would be interesting to see if matching alloy filler welds can be heat treated back to T6..
T651 is a wee bit more brittle or less ductile than T6. Welding in T0 is preferred, then heat treated to desired strength.
I did some 6061 tube which I annealed to T0 to bend and then welded. Aluminum does this funky thing called over aging which is probably why your welds failed in the HAZ while the AlumiWeld braze didn't..just a SWAG.
Anyhow, gloves and bandsaw? I don't believe that hooey tale. I'm wearing them because I can keep my booger hooks away from moving blades.
Aaron, look into DCEP welding of Aluminum using high-purity He2. not Ar. common in the aero snd semi-conductor field for thick section assys.
Got me curious. I've never tried it myself.
1000 Years ago I had a GT Zaskar that was made from 7009 material. The bike shop had a video featuring the making of those frames, and they specified that the 7xxx material needed to have pre & post weld heat treatment done. The rest of their Al frames were 6061 at the time.
Couple things for you to try: Try a He/Ar mix?
Maybe try on DC with High Purity He?
How about with Pulse?
Maybe control cooling?
Maybe weld in a chamber. possibly the O2 hitting the backside of the weld causing embrittlement like on Ti?
A few years back I had some costume out riggers made for extendable lowboy out of t6 aluminum
They worked great until they got broken the welds would hold but the metal turned brittle next to the welds
And that prime welder sounds like a better weld
a much smoother sound
Welding technology has come a long way
From the ol Lincoln cracker box 180 amp from Sears catalog
Good experiment. Thanks for doing that.
‘Beat the piss out of it’ haha 😂. I thought that was an Australian saying. There you go, nice
thought the same thing
I welded 7075 without pausing and created a smooth weld without dimes and it seemed to hold a LOT better.
This was a really great video for information. Thanks for taking your time to make this and show us
I built cradles for turbine gpu's. We would cut all the tubes and gussets and send them to heat treat to take them from T6 to T0. Once the welding was done and inspected we would send the entire weldment back to heat treat and take them from T0 back to T6.
The weld always comes out T0 I believe...unless it's heat treated.
gpus? Graphics Processing Units? What?
7020 also cracks nicely. you can even grind the crack out! it's like a ticking time bomb then
Led by Prof. Xiaochun Li, a team at the UCLA Samueli School of Engineering set about addressing that problem. In the course of doing so, they fabricated thin rods made of 7075 infused with minuscule particles of titanium carbide. These rods were then placed between larger pieces of the aluminum alloy which were about to be joined, acting as a filler. When the rods and adjacent material were subsequently melted in an arc welding process, the nanoparticles eliminated the uneven flow issue.
"Nanoparticles make the elements in the liquid metal solidify together more uniformly, thus preventing phase segregation," Li tells us. "Phase segregation normally will block the liquid metal flow during cooling, thus inducing shrinkage and cracks without liquid filling. Since the metal solidifies more uniformly after adding nanoparticles, the liquid metal flows better during solidification, thus no cracking due to segregation."
A close-up view of one of the AA7075 welds
A close-up view of one of the AA7075 weldsUCLA
The resulting welded joints have a tensile strength of up to 392 megapascals - by contrast, the commonly-used 6061 aluminum alloy has a weld strength of 186 megapascals. What's more, it is believed that post-welding heat treatments could boost the strength of the 7075 welds up to 551 megapascals, which is on par with the weld strength of steel.
Although the alloy is already used in items such as airplane wings and fuselages, sheets of it typically have to be riveted together. The scientists now hope that the ability to weld it will increase its applications.
"The new technique is just a simple twist, but it could allow widespread use of this high-strength aluminum alloy in mass-produced products like cars or bicycles, where parts are often assembled together," says Li. "Companies could use the same processes and equipment they already have to incorporate this super-strong aluminum alloy into their manufacturing processes, and their products could be lighter and more energy efficient, while still retaining their strength."
I once spent half a morning welding on a panel to a piece of equipment. Weld, crack, grind, weld, crack, cut it out, you get the picture. After getting boss man, we didn't find a single weld on this entire thing, just rivets. Our only conclusion was that it was either 2024 or 7075
It is necessary to rename the channel to 7075 and then the welding will be successful.
Nice one 😂.
Very interesting 😶 Never saw this before...👍
Thanks for the thorough research.
Very informative! Thanks for putting in the work.
perhaps preheat would work because the brazed joint didn't break during the bend test
Only thing you didn't try was preheat or annealing prior to welding
👍👍👍 Already subscribed years ago those were extra thumbs ups in addition to the one I already clicked on
Awesome video! Good information. 👍👍
Thanks for the video, always educational and sometime funny
Very informative. Love your videos
Interesting results.
Thanks for showing us!!
2024 is the one with a lot of copper. I’ve always heard that it can be welded without any drama but the copper migrates to the edges the weld which creates corrosion and strength issues.
I tried 2024 once and no matter what I did, I could not get anything to work to any degree worth considering useful. Did the same with 7075 as Aaron did here and got about the same results as he did here which makes me think that the copper is the problem because when you look at 7005 for example, it is considered readily weldable and its max allowable copper is 0.1% where as 7075 should be between 1.2~2.0% and 2024 being between 3.8~4.9%
I've heard some say its the Zinc Content in 7075 but I dont think that is the case because although less, 7005 does have fairly high zinc content (4.0~5.0% vs 5.1~6.1% for 7075). And on that note, 2024 has a max allowable zinc of 0.24% so really, the copper content seems to be real driving factor here.
Some Zinc in 7075 etc evaporates near normal welding temperatures producing a spongy layer that is really brittle. I guess it could theoretically be welded at (very) elevated atmospheric presures in a chamber or something...
Very interesting, thanks for sharing.
Very interesting. I wonder about the "welding" rod that's more like soldering or brazing. I think that's usually used with a torch. Obviously, the temper will be gone, though. It kinda reminds me of cast iron. How does it compare to cast aluminum?
I think in the mid '90s I had a mountain bike frame made with 7005...and I know a lot of components were machined from 7075
That alumina weld rod? Is that the hobo freight stuff? I bought some of that stuff years ago and haven’t used it yet. Supposedly you don’t need much heat, that’s why I got it. Thought it may be handy to keep in my tool box.
Years ago, I thought I hit the jackpot. The person whoever figures out how to weld steel to aluminum is going to be very wealthy very quickly.
I have it a shot. Some thinner gauge material. I can’t remember what filler rod I used. But it seemed like it worked!!! I looked at the piece closely…no cracks. I tried to break it by hand…no go. It held. I thought “man, I must have come across, by accident, the secret machine settings, filler, technique etc. I’m going to be rich!!!”
Then I put the piece in a vise and gave it a wack with a hammer.
All of my dreams vanished within a split second. I went from “I’m going to buy a yacht and a big log cabin in the mountains” to “quit playing around and get back to work, loser. Youre a welder, and you’re stuck in that dark world of bright light forever” ☹️
"dark world of bright light"
I like that, never heard it before
You can get steel 'welded' to aluminum, they produce it in big sheets by laying a sheet of aluminum on top of a sheet of steel then covering it with explosives, the force and heat join the two together. Or its something long those lines
@@nunnas5393 See wikipedia "Explosion welding"
I welded stainless to aluminum one time in welding school. It was out of carelessness. I mistakenly picked up a stainless rod that i thought was an aluminum rod. It was making some colors and being difficult, so i forced it more. In the end, i welded 2 aluminum plates with a stainless rod. I figured out it was a stainless rod after i finished by trying to bend the rod. 😔
Haha yes indeed, can't even count how many times customers have brought in steel and aluminum to be fused together
I’ve used mostly the white Wolfram Elektrode for this
Good to know
Love your channel
Thanks for sharing the test. I too have heard the 7000 series aluminum is non weldable.
You introduced silica into the weld with 6061
When heated during welding, 7075 aluminum's molecular structure causes the aluminum, zinc, magnesium, and copper to flow unevenly, resulting in cracks. This is known as phase segregation. 2024 has the same issue.
Awesome video!! I enjoy machining/using 7075 for certain applications, given it's strength....but have never tried welding it.
Actually; this video just gave me an idea for a project that I've been putting off, where 7075 would be preferable and the weld wouldn't be structural.
On the larger blocks; did the higher heat input required to weld, anneal the entire part?
Thanks!
Please do a video about stress corrosion cracking. Everything that you just showed in this video is equally applicable to all 7,000 and 2000 series aluminum alloys. The only time either one of these two alloy series should be welded is for cosmetic applications. The only time I've successfully welded either one of them is to repair a blow mold from time to time and only for cosmetic fixes where JB Weld would have worked just as well too. JB Weld might even be stronger in those applications😢
The problem with 7075 is not just the copper, which isn’t a serious problem, it’s a moderate amount, not exceeding 2%. It’s the zinc which is a problem. There’s 5 to 6 percent zinc in 7075. The brittleness is from the zinc. Zinc is strong, but brittle. This just glues to show that standards are often correct.
great stuff very informative. Thank you. How Many amps were you pulling on the chunky pieces?
Thanks
Well that was awsome thanks completely understood 🤝👍
Worked with a guy that was an engineer (not a good one) that made an entire sub frame for a race car that his son would be racing out of 7075 because he got a great deal on it. A weld engineer friend stopped by, had him throw the subframe out into the snow on a very cold day, then hit it with a hammer. Let us just say we saved his son from a bad day
Very interesting.. So 7075 is good for machining non structural parts maybe? It seemed to fracture easy..Also the fractured has the "rotted" aluminum look.
Always entertaining.
What’s the main use of 7071?
Thanks for doing those tests so I don’t have to!
Thanks bro👍🏻
Great video, thanks!
As an aircraft mechanic I’ve driven lots and lots of rivets into 7075 and of course heard the same thing everybody else did, that is not weldable. Having watched your video though, I’m curious. I wonder what would happen if you annealed the material that you had previously welded.
*Damn You....*
*quote "i'll be damned"*
*Very Entertaining*
The easiest way I found to clean aluminum out of a burr is a piece of steel handy just grind on that a little bit and the aluminum comes right out
7075 the cast iron of the aluminiums ;-)
Nasty shit, but great strenght
Kinda weird, because 7005 is apparently usual stuff for bike frames, quite similar to 7075 with zinc and magnesium but with no copper.
I have repaired three MTB Frames successfully with Almg 4,5 MnZr 3.2 / 2.4 without Thermo Operation, just wait for three Months that the Alu get his strength back.
In Germany we say: Bis sich das Gefüge richtet.
I thinked they are welded before also it must work 🤷 I’ved tried it and it has worked and still hold 😂
I'd be curious how the silicon brazing rod would do
The only time I've ever successfully welded 7075 to itself or anything else was fixing molds. Say you had an aluminum mold that got a screw loose inside of it or something of that nature and your repair was simply just filling up a blemish and machining it back down for cosmetic reasons on the finished product. Otherwise it is subject to what's otherwise known as stress corrosion cracking. In the case of welding 7075 to 6061 with 4000 series filler it might not crack this afternoon or in 2 days but sometime in the next 2 weeks to 6 months is going to crack and fail.
I've been involved with both steel making and the manufacturing of metallurgical additions for Aluminum. In the case of steel, the bath temperature is around 3000°F, so additions to it have little problem being melted also. However with Aluminum, that is not necessarily the case. Aluminum melts at little over 1200°F, so how do you add something like Titanium that melts at over 3200F or Silicon is 2588°F.
I'm an automation guy not a metallurgist, but I worked on the process to compress Titanium fines into "compacts" that are dense enough to sink when thrown into the Aluminum bath. So think about the melting point dilemma, what next? Well they don't "melt" but I'm told, eventually they will devolve. So with like condition, like salt in water, they are un-reacted but still present with in the crystallization process when freezing occurs. With different freezing temperatures, is it a surprise that brittle conditions occur...not really. Think about iron, if it is plunged into cold oil or water, the crystal structure is randomized as it freezes, and it become much harder...which is to say...more brittle.
One other consideration, if pulses of heat are being added to the Aluminum, that implies gradients of temperature, and this may contribute to the disorderly freezing process.
makes me wonder how well it would hold up to friction stir welding