Any of you fabricator/welders see this??
https://phys.org/news/2019-01-nanotechnology-enables-weld-previously-un-weldable.html
https://phys.org/news/2019-01-nanotechnology-enables-weld-previously-un-weldable.html
Welding 7075
- Thread starter Tantrum Cycles
- Start date
mothafucking STIFF aluminum frames
7075 isn't going to be stiffer. The change in material stiffness is low and you can use thinner wall thickness
And I will claim lower weight than carbon frames
I'm still thinking of machining them out of big blocks of 7075 even though this thread is about welding.
I'm having a fantasy.
I'm having a fantasy.
well Pole could then weld their frames together. I'm thinking alignment after heat treat would be a bitch.
I would just like to take some 7075 tubes and weld them to 7075 lugs.
heat treat?
7075?
7075?
Well, since welding 7075 is a new topic, I will assume that it will need heat treat after welding, just like any other aluminum...7075 Billet is heat treated and aged..
They used to say 4130 didn't need heat treat after welding.....I've never put an unheatreated 4130 part on a race car, who knows.
They do mention heat treatment in the article, over twice as strong as a 6061 weld, which is roughly the case on billet tensile strength comparison as well
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i've ridden plenty of janky 4130 frames un-heat treated... only a few cracked. 
I'm not as sure. Only because things like dropouts and linkage attachment parts still have a kind of minimum size and carbon is so much lighter in those applications. Also can only go so thin on a tube before it gets real easy to dent (and then you lose the benefit of aluminum (crash proof)).
ya and I welded the steel frame on my motocross bike with a coat hanger back in the olden days....i've ridden plenty of janky 4130 frames un-heat treated... only a few cracked.
I'm not as sure. Only because things like dropouts and linkage attachment parts still have a kind of minimum size and carbon is so much lighter in those applications. Also can only go so thin on a tube before it gets real easy to dent (and then you lose the benefit of aluminum (crash proof)).
And true, 6061...for example, I use it for rockers because the limit is how thin I can machine, not material strength.
But my current 6061 frames are almost as light as competitive carbon, with not overly thin tubes. My 180/165 mm 29er weighed 30.5 lbs with pedals. It DID have some wicked cool WeAreOne composites wheels and carbon crank. but still.
We are forum members, we are all fabricators and welders, we know all of the things.
EDIT- Have Intense secretly been using 7075 all these years? It would explain the cracks at welds.
What is your frame weight?
Bikes I've had lately:
2017 Trek Remedy Carbon 4.4!!! lbs no shock (rock broke the downtube)
2018 Transition Sentinel 8.6 lbs no shock (indestructible)
2019 Scott Ransom Carbon 5.5 lbs no shock (haven't built it yet)
I'd love to have a 6 lb aluminum frame that didn't break in 1 season.
CNC 7075 lugs then bond in 7075 tubes? Must be some modern adhesives that will handle that.
Did GT have issues with bonding when they did lugged carbon frames? That was so long ago they were probably using animal glue.
If you're talking about the STS and Lobo, they were a thermoplastic noodle pushed through aluminium inserts and cured. And yep, the aluminium used to seperate from the plastic if the frame didn't crack first.
I've seen some trials bikes that are already going out with 7075 frames. Well.. partially. Clean for example uses 7075 on the CNC'd bits on their frames.
https://cleantrials.com/en/cuadros/214-x1-26-frame.html
Don't ask me how they made it work.. magic or something
https://cleantrials.com/en/cuadros/214-x1-26-frame.html
Don't ask me how they made it work.. magic or something
Inter
[QUlyOTE="PepperJester, post: 4326144, member: 8052"]I've seen some trials bikes that are already going out with 7075 frames. Well.. partially. Clean for example uses 7075 on the CNC'd bits on their frames.
https://cleantrials.com/en/cuadros/214-x1-26-frame.htmlra hdxbdha
Don't ask me how they made it work.. magic or something[/QUOTE]
Interesting. They are welding 6061 tubes to 7075 lugs.
But it’s the 7075 tubes I want
[QUlyOTE="PepperJester, post: 4326144, member: 8052"]I've seen some trials bikes that are already going out with 7075 frames. Well.. partially. Clean for example uses 7075 on the CNC'd bits on their frames.
https://cleantrials.com/en/cuadros/214-x1-26-frame.htmlra hdxbdha
Don't ask me how they made it work.. magic or something[/QUOTE]
Interesting. They are welding 6061 tubes to 7075 lugs.
But it’s the 7075 tubes I want
My limited googling ability is bringing up similar tensile strength for the scandium alloyed 7000 series that Santana makes frames out of. Our engineer has told me that it's significantly stronger than 7005 and much stronger than 6061. Now that Easton's out of the game we get our tubing from an American metalurgist in Taiwan and it's supposedly better than the Easton stuff. For your next run of frames look him up, but the cost might not be that different from carbon.
There are definitely stronger weldable alloys than 6061. We used a scandium 7005 for my Magic Link bikes. When that alloy first appear, I remember hearing rumors of it being brittle, but I think they tweaked the alloy and we didn’t have any problems
Lately, 6069 and/or 6062 are being touted by the Taiwan factories as the best weldable allows. Stronger tensile AND more ductile
I didn’t bother for my first batch, partly because I used an “off the shelf” top tube but mostly just to keep things simple for my first run
I think if carbon hadn’t had come along when it did, aluminum alloys and forging techniques would have resulted in frames that are stronger, lighter and less ocean fill. And I would like that
Are his intials JD?
Yay, more bike parts i cant afford!
I don't know. I just know he's the only one we could find good quality scandium tubing from and he does custom diameters, butting, and tapering despite relatively small quantities.