I have a ruler made from thin (.02") stainless steel. I'm wondering if I
can get the same stiffness and springiness from aluminum sheet. I don't
mind increasing the thickness, but I don't want to increase the overall
weight. Are there types of aluminum that have the same qualities as
hardened steel?

From:	jbuch
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 08:57:17 -0600

Ken wrote:

> I have a ruler made from thin (.02") stainless steel. I'm wondering if I
> can get the same stiffness and springiness from aluminum sheet. I don't
> mind increasing the thickness, but I don't want to increase the overall
> weight. Are there types of aluminum that have the same qualities as
> hardened steel?

As you know, you can buy bicycles with steel or aluminum frames ( and
titanium and carbon fiber composite, and some other materials).

So, it is certainly possible to substitute a larger diameter aluminum
tube or thicker tube for steel in a sporting goods structure.

It helps to be more direct about the applicatin than calling it a
"ruler", as that creates a false impression.

There are no aluminum alloys that have the same qualities as hardened
steel, unless it is a pretty inferior hardened steel, and then only the
strength may match, not the elastic stiffness(Young's modulus).

You speak as if you know that some steel strip works, you have no
materials understanding, and you would like to find something lighter
than steel for your snowboards..... and not have to understand much more
about the materials.

You can use an aluminum strip about 2.6 times thicker than your existing
steel strip, and it will have nearly the same weight.

You can select from a high strength aluminum strip such as 7075-T6 to
get the best strength that you can get. The resulting bending strength
and bending stiffness will be somewhat like that of the steel
(unspecified) that you used.

One thing that you can do is to experiment. Well, you'll have to do
that anyway.

Do you have a metals supplier around for your business, or are you doing
this in your garage?

Jim

--
................................

Keepsake gift for young girls.
Unique and personal one-of-a-kind.
Builds strong minds 12 ways.
Guaranteed satisfaction
- courteous money back
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http://www.alicebook.com

From:	Ken
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 12:00:11 -0800

I'm just doing this in my garage and it's for the base of a snowboard.
My thinking is that a typical snowboard base of polyethylene offers very
little in structure to the snowboard, so why not make the base metal.
The best snowboards have a springy flex, so that's why I thought the
hardened stainless steel ruler was a good example. The composition of
the snowboard would be a sandwich construction with, starting at the
bottom, the sheet metal base, a layer of fiberglass, a wood core,
another layer of fiberglass, and finally a plastic top sheet. The only
reason why I asked about aluminum was because the stainless steel was so
much more expensive. I suppose I could use regular steel, but I'm
worried about rusting. The base would get scratched, so I don't think I
could use galvanized either. So I guess I'm looking for a springy,
non-rusting, affordable sheet metal. I think I will take your advice and
get some test strips of each and see if the aluminum at 2.6 times
thicker has the similar qualities I'm looking for.

In article ,
jbuch wrote:

> Ken wrote:
>
> > I have a ruler made from thin (.02") stainless steel. I'm wondering if I
> > can get the same stiffness and springiness from aluminum sheet. I don't
> > mind increasing the thickness, but I don't want to increase the overall
> > weight. Are there types of aluminum that have the same qualities as
> > hardened steel?
>
> As you know, you can buy bicycles with steel or aluminum frames ( and
> titanium and carbon fiber composite, and some other materials).
>
> So, it is certainly possible to substitute a larger diameter aluminum
> tube or thicker tube for steel in a sporting goods structure.
>
> It helps to be more direct about the applicatin than calling it a
> "ruler", as that creates a false impression.
>
> There are no aluminum alloys that have the same qualities as hardened
> steel, unless it is a pretty inferior hardened steel, and then only the
> strength may match, not the elastic stiffness(Young's modulus).
>
> You speak as if you know that some steel strip works, you have no
> materials understanding, and you would like to find something lighter
> than steel for your snowboards..... and not have to understand much more
> about the materials.
>
> You can use an aluminum strip about 2.6 times thicker than your existing
> steel strip, and it will have nearly the same weight.
>
> You can select from a high strength aluminum strip such as 7075-T6 to
> get the best strength that you can get. The resulting bending strength
> and bending stiffness will be somewhat like that of the steel
> (unspecified) that you used.
>
> One thing that you can do is to experiment. Well, you'll have to do
> that anyway.
>
> Do you have a metals supplier around for your business, or are you doing
> this in your garage?
>
> Jim

From:	Uncle Al
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 13:20:11 -0800

Ken wrote:
>
> I'm just doing this in my garage and it's for the base of a snowboard.
> My thinking is that a typical snowboard base of polyethylene offers very
> little in structure to the snowboard, so why not make the base metal.

Snow doesn't stick to HDPE. Snow does stick to polar surfaces like
metals. Gonna have to give a metal bottom a spray of WD-40 before
hitting the slopes.

> The best snowboards have a springy flex, so that's why I thought the
> hardened stainless steel ruler was a good example. The composition of
> the snowboard would be a sandwich construction with, starting at the
> bottom, the sheet metal base, a layer of fiberglass, a wood core,
> another layer of fiberglass, and finally a plastic top sheet.

Sounds like a job for composite. Take the hint.

> The only
> reason why I asked about aluminum was because the stainless steel was so
> much more expensive.

Common stainless steel is weak metal. Hardened tool steel or drawn
spring steel is something entirely different. Knife stainless is
something different.

> I suppose I could use regular steel, but I'm
> worried about rusting. The base would get scratched, so I don't think I
> could use galvanized either. So I guess I'm looking for a springy,
> non-rusting, affordable sheet metal. I think I will take your advice and
> get some test strips of each and see if the aluminum at 2.6 times
> thicker has the similar qualities I'm looking for.

Titanium! Leave a trail of sparks on the way down. OK, OK...

http://www.liquidmetal.com/index/default.asp
http://coatings.liquidmetal.com/

Go for the gusto. Ditto non-stick pentagonal alloys (Cybernox
cookware),

http://www1.ast.leeds.ac.uk/~knapp/Nicola.pdf

http://www.asc2004.com/23rdASC/summaries/a/AP-03.pdf
http://www.dtic.mil/matris/sbir/sbir012/a01-202c.pdf

If you need one set of properties at the surface and another
conflicting set of properties in the bulk, then you cover the bulk
with a specialized surface rather than accept a bad compromise
throughout.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

From:	Michael Dahms
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 12:16:50 +0100

Ken wrote:
>
> Are there types of aluminum that have the same qualities as
> hardened steel?

No.

Michael Dahms

From:	Uncle Al
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 09:10:37 -0800

Ken wrote:
>
> I have a ruler made from thin (.02") stainless steel. I'm wondering if I
> can get the same stiffness and springiness from aluminum sheet. I don't
> mind increasing the thickness, but I don't want to increase the overall
> weight. Are there types of aluminum that have the same qualities as
> hardened steel?

You won't get hardened or drawn spring steel in aluminum. Not
nearly. Intermetallics (NiAl, TiAl) might be interesting but they are
generally expensive by components and hard to work after forming.

Aluminum/scandium for Russian missile skins and baseball bats.
Aluminum/copper for Wright brothers' airplane engine.
NiAl for Reagan's China Clipper (needs a percent of copper or so to
ease brittleness; fabricate near-net by solid flame of powdered
compacted components).

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

From:	Mark Thorson
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 04:21:21 GMT

From:	Ken
Subject:	Re: Can aluminum be hardened?
Date:	Fri, 21 Jan 2005 02:28:29 -0800

The application is for the base of a snowboard so a rib and holes are
out of the question. I still want it to be able to flex. I like the
spring-like flexibility of the ruler. I have thought to try titanium,
but like stainless it isn't cost effective. If I'm not mistaken,
aluminum and steel have approximately the same specific strength. But do
they also have the same specific modulus. Steel can be hardened, but I
don't know if there is hardened aluminum.

In article <41F08367.79812176@sonic.net>,
Mark Thorson wrote:

> Ken wrote:
>
> > I have a ruler made from thin (.02") stainless steel. I'm wondering if I
> > can get the same stiffness and springiness from aluminum sheet. I don't
> > mind increasing the thickness, but I don't want to increase the overall
> > weight. Are there types of aluminum that have the same qualities as
> > hardened steel?
>
> Would a reinforcing rib down the center of the ruler be objectionable?
> How about holes to lighten the ruler to meet your weight objective?
>
> Have you considered titanium?

From:	Mark Thorson
Subject:	Re: Can aluminum be hardened?
Date:	Sat, 22 Jan 2005 01:18:30 GMT

Ken wrote:

> The application is for the base of a snowboard so a rib and
> holes are out of the question. I still want it to be able to flex.
> I like the spring-like flexibility of the ruler. I have thought to
> try titanium, but like stainless it isn't cost effective.

Nobody makes springs out of aluminum. Metals used for
springs include certain steel alloys, certain brass alloys,
phosphor bronze, beryllium copper, certain titanium alloys.
If you can't afford stainless, you probably can't afford
anything except steel.

Any flat metal spring can be improved by shot peening.

As Uncle Al suggested, you're probably better off with
a laminate. Always try to avoid asking one material
to do two (or more) things, such as being a good spring
material and being non-corrosive. A spring steel core
surrounded by a fiber-reinforced plastic would be a
good starting point.

I suggest you rethink whether you can tolerate holes.
Holes in a steel core would allow you to control flex.
For example, would it be useful to allow twisting flex?
Holes along the central axis would provide additional
twist compliance. It's not real obvious, but twisting
puts tensile stress on the central axis.

From:	Ken
Subject:	Re: Can aluminum be hardened?
Date:	Sat, 22 Jan 2005 02:18:56 -0800

I like the idea of a composite. And the Liquid Metal and Quasicrystals
look interesting. I'm going to try a aluminum base laminated to some
carbon fiber to give it some spring qualities. I'd like to try one of
the coatings on the aluminum base. Are the quasicrystal technologies
available now, or are they still in the R&D stage? Does anyone know of
companies that apply these coatings? I searched and found many articles,
but no companies offering these services.

In article <41F1AA0B.5A411380@sonic.net>,
Mark Thorson wrote:

> Ken wrote:
>
> > The application is for the base of a snowboard so a rib and
> > holes are out of the question. I still want it to be able to flex.
> > I like the spring-like flexibility of the ruler. I have thought to
> > try titanium, but like stainless it isn't cost effective.
>
> Nobody makes springs out of aluminum. Metals used for
> springs include certain steel alloys, certain brass alloys,
> phosphor bronze, beryllium copper, certain titanium alloys.
> If you can't afford stainless, you probably can't afford
> anything except steel.
>
> Any flat metal spring can be improved by shot peening.
>
> As Uncle Al suggested, you're probably better off with
> a laminate. Always try to avoid asking one material
> to do two (or more) things, such as being a good spring
> material and being non-corrosive. A spring steel core
> surrounded by a fiber-reinforced plastic would be a
> good starting point.
>
> I suggest you rethink whether you can tolerate holes.
> Holes in a steel core would allow you to control flex.
> For example, would it be useful to allow twisting flex?
> Holes along the central axis would provide additional
> twist compliance. It's not real obvious, but twisting
> puts tensile stress on the central axis.

From:	Uncle Al
Subject:	Re: Can aluminum be hardened?
Date:	Sat, 22 Jan 2005 08:32:25 -0800

Ken wrote:
>
> I like the idea of a composite. And the Liquid Metal and Quasicrystals
> look interesting. I'm going to try a aluminum base laminated to some
> carbon fiber to give it some spring qualities. I'd like to try one of
> the coatings on the aluminum base. Are the quasicrystal technologies
> available now, or are they still in the R&D stage? Does anyone know of
> companies that apply these coatings? I searched and found many articles,
> but no companies offering these services.

1) Grow up - don't top post.
2) You have the references, Sitram under the trademark Cybernox and
coatings.liquidmetal.com
3) Research is not inexpensive. You had better have a profitable
product in mind if you want them to palaver with you.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf