7075 nanotech welding: any news?

Discuss light weight issues concerning road bikes & parts.
bm0p700f
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by bm0p700f

7075 is used for hardness as well as strength. For extruded tubes it's not the best choice as it difficult to extruded reliably or it would be used for rims. Also it.

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XCProMD
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by XCProMD

robertbb wrote:2014 is the highest quality for bars/stems.
Why?


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bm0p700f
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by bm0p700f

It can be extruded and bent without getting stress cracks. Try that with 7075 and if it survived manufacturing it would not pass safety tests.

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by XCProMD

Stems are not extruded. True that 7075 is very hard to forge, but there are stronger alu alloys than 2014 that can be forged and hydroformed in 3D and have good ductility and toughness, like many 6000 and some 7000 series.

“Best” is a too ample description but plain 2014 can only be considered “among the best” when it comes to machining costs.


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bm0p700f
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by bm0p700f

Bars are extruded. Stems are forged and 7075 is not for forging either.

2014 or similar alloys are used for forging hubs and stems because the material does the job and has good fatigue resistance. Ots also cost effective to use. Forging strengthens the material.

6000 series alloys are used for rims because it can be extruded into thin walled sections.

7075 is perfect for CNC parts where strength or wear resistance is important.

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C36
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by C36

bm0p700f wrote:It can be extruded and bent without getting stress cracks. Try that with 7075 and if it survived manufacturing it would not pass safety tests.
Sure it existed, ITM millenium bar was made out of 7075. But again it has limited interest for the end product.



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bm0p700f
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by bm0p700f

Exactly expensive so limited interest. It not easy to do which is why not every one is at it.

Bars are extruded. Stems are forged and 7075 is not for forging either.

2014 or similar alloys are used for forging hubs and stems because the material does the job and has good fatigue resistance. Its also cost effective to use. Forging strengthens the material.

6000 series alloys are used for rims because it can be extruded into thin walled sections.

7075 is perfect for CNC parts where strength or wear resistance is important.

Those are general rules and if you are trying to make a commercial product that will sell then sticking to what works is often best.

7075 is simply does not offer advantages over 2014 for forged stems. I suppose you could make a cnc stem from 7075. Why though. Why.

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by alanyu

bm0p700f wrote:
Wed Oct 16, 2019 10:29 am
Exactly expensive so limited interest. It not easy to do which is why not every one is at it.

Bars are extruded. Stems are forged and 7075 is not for forging either.

2014 or similar alloys are used for forging hubs and stems because the material does the job and has good fatigue resistance. Its also cost effective to use. Forging strengthens the material.

6000 series alloys are used for rims because it can be extruded into thin walled sections.

7075 is perfect for CNC parts where strength or wear resistance is important.

Those are general rules and if you are trying to make a commercial product that will sell then sticking to what works is often best.

7075 is simply does not offer advantages over 2014 for forged stems. I suppose you could make a cnc stem from 7075. Why though. Why.
Pro vibe stem is made of 7075; 3T arx team and Zipp service course sl also. I think those are forged stem.

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by XCProMD

Fatigue resistance depends on:

- Yield strength
- Surface roughness / defect depth and tip radius
- residual stresses

If welds are present, fatigue strength at the weld toe will be the same regardless of the aluminium grade. Otherwise, and provided the manufacturing method allows to control surface roughness (machining, forging do), its all up to yield strength as long as the alu is heat treated after forging or prior to machining (no residual stresses). Then 6000 or 7000 series will offer better fatigue strength, which comes handy to accommodate a higher stress range when going thinner.

7005 can be easily extruded, hydroformed and forged. 7075 is definitely tricky but doable nowadays. I agree there is little point in going so far in yield as the latter.

2014 is easy peasy but will not allow to go very thin.

Extralight makes very light stems machined out of 7075 T6 forged billets. Those weights are impossible to reach with 2014. Of course it is very expensive. This is Weightweenies after all.


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Stolensteel
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by Stolensteel

wonder what Hambini thinks about this all story

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