Aluminum cannot be treated in any way that will give it spring characteristics
Not entirely correct. Aluminum can and is heat treated. That is the “T” rating seen in the material callout (T2, T4, T6). Heat treatment of aluminum alloys raises the yield strength (the point at which it bends) closer to the breaking point exactly the same as heat treating alloys of steel. That allows it to flex further before bending. T0 aluminum flexes like cheese, T6 flexes quite far before bending.
Aluminum springs aren’t used much because their fatigue resistance has low limits. If you raise the yield strength of steel and flex it no more than halfway to its yield point, it will essentially flex forever. Do exactly the same with aluminum and it will eventually break.
That’s why planes are X-ray-ed periodically. The flexing caused by take-offs and landing and pressurization fatigues the metal and will eventually fail it.
Heat treating aluminum cannot give it the hysteresis characteristic necessary for a spring. Heat treating aluminum does change its grain structure to affect its hardness, which is what it’s used for.
That same flexing that you mention would also happen to an aluminum spring. Aluminum has poor tensile strength and fails as it’s stretched during tensile loading of the metal, which is one characteristic of vibration.
You cannot make a spring out of aluminum. If you doubt me, do the research.
Yes George is being creative and if this for his own use fine, But if it is for a child or children they can find a way to break an anvil. Experimenting at a child’s possible injury is not responsible thinking.
It seems to me though that those anodized aluminum springs are for more decorative purposes (jewelry useage…) rather than something to go through repeated extension and compression cycles.
My vote at this point is for the baby food jar lids although if I were doing it I’d probably wire it up for a battery, chime, and push button.
Aluminum can lids are typically made of 5082 or 5182 alloy aluminum. These grades can be hardened by cold working, but not heat treating. Heating will not put any precipitates back into solution, and therefore quenching will not precipitate anything that will increase strength. aluminum can tops, like the softer body, develop hardness through rolling the sheet.
Insightful, I hate to tell you this, but these aren’t springs. They’re decorative for making earings and jewelry, made to emulate springs only. They’re not functional except as jewelry.
TSM, a spring is just something that returns to its original shape after flexure. There is no reason aluminum can’t be used as a spring. And as insightful posted, it can be made into a spring.
Heat treat does affect hardness, sure but its primary function is to increase strength. 7075 T3 aluminum has a yield stress of 56 ksi and ultimate tensile strength of 67 ksi is higher than 1020 cold drawn steel. In the T6 heat treat, yield is 73 ksi and ultimate is 83 ksi, higher than hot rolled 1040 steel and close to cold drawn, So Yes, it is strong enough in tensile and compression.
Elongation for the 7075T6 is only 9% compared to 1040’s 18% so yes, the steel will be a better spring but there is no reason aluminum cannot be a spring with limited cycle life. A leaf spring may be the best configuration but not the only one.
??? 66" wide? More than 5’?? For aircraft with gross weights up to 2200 pounds? That’s some ultralight!
Here’s what they say "Grove Aircraft can provide a complete custom landing gear, ready to bolt on, designed for your individual airplane. We have built landing gear for over 1,000 different types of aircraft. "
So they are aircraft landing gear, and are, therefore, springs.
Yes, that’s an ultralight. An MG Midget weighs almost that. A Cessna 150’s dry weight (before fluids and people) is almost that.
It might help to realize too that no engineer or aircraft mechanic in his right mind would put wheel struts on an aircraft the load rating of which is the same as the aircraft weight… or even close, for that matter. I would not use a strut with a load rating of 2200lbs max on any aircraft weighing more than 850lbs fully loaded. That’s a 2.5x “error budget”, not at all excessive for a critical aircraft parts.
I cannot open the video, but even aluminum has some minimal ability to return to its original form after some minimal bending. Take an aluminum strap and you can wobble it back and forth and it’ll return, but that doesn’t make it a spring. A wooden board or PCV pipe will do the same thing too, the board much better than aluminum actually, but PVC and wood aren’t considered spring material either.