formula94lt1
Automotive
Hi all this is my first post. I was thinking about how aluminum is conventionally used to make automotive chassis for certain kit cars by welding aluminum panels together. I was only interested in this way of construction since it seems more feasible to create such a thing in my garage than hydroforming. As far as I know 6061 t6 is the most commonly used which is a medium strength alloy of aluminum that is weldable and corrosion resistant but of course suffers from a pretty high(40+%) loss in strength around the welds. This takes it from being a medium strength alloy to something quite a bit less. So I set out to find some other way of getting the strength to weight benefits of aluminum alloy without any sort of welding. This also opened up the options of aluminum that could be used to non-weldable alloys such as 2024 and 7075 which are stronger and significantly stronger respectively. The later is actually another reason why wanted to persue another form of construction other than welding. Using these stronger alloys naturally allows for less material to be used for a lighter weight design and/or for a stronger design. I looked shortly into riveting which sounded like more of a pain than welding just to get to the point of being able to drive them in. Then I thought of bonding with adhesive like with composites. So I looked into epoxys and such and finally found something specifically for bonding aluminum by loctite called "H8000." I read a review where they were replacing welds with this stuff so I had to give it serious consideration. So after some simple math I found it not unreasonable to overlap the panels a certain amount as a function of thier thickness and tensile strength and bond them. Then I realised that I would need some way to overlap the panels at different angles depending on how that panel fit in relation to the ones around it. After tinkering with a few ways to do this I considered one way best. That's to take two panels and join them at their edge at an angle then take two more slightly thinner panels (bending them to the same angle) that overlap the two forementioned in the front and the back just enough to provide equal shear strength to the larger panels when bonded. Then I ran into the problem of the alloy I wanted to use(7075 t6), and most other aluminum alloys of appreciable strength, not having a high enough percentage of elongation to make a sufficiently short radius bend to contour to the surfaces of the larger panels. Now Ive thought of using composite panels to sandwhich the aluminum ones together but the rate of thermal expansion is far too different between the two not to cause serious problems and thats if the adhesive would bond to the composite as well as the aluminum if at all. SO FINALLY for my questions... Can 7075 t6 be heated without changing its strength to make a very small radius bend? Any guide to a temp to radius bend for various thicknesses? Obviously the point is to not have any flex in the joining of the aluminum panels and any radius at all in the front and back sandwhiching panels hinders that as apposed to welding, but Im not sure exactly how much and that if there was some radius to the joining 7075 t6 panels would they be less rigid than welding a weak alloy? Any alternative solutions are welcome of course.... sounds like this one has a few flaws.
