I was wandering aimlessly around the internet and found the Hexcel web site.

They have a lot more products than they use to have, one of which is pretty much made for uses as BMW .

http://www.hexcel.com/products/indus...exmc-materials

There is a chart there which shows Hexmc as being a bit stiffer than

Steel and about half the weight of aluminum. And slightly lighter than Magnesium.

Dan

wrote in message
...
I was wandering aimlessly around the internet and found the Hexcel
web site.

They have a lot more products than they use to have, one of which is
pretty much made for uses as BMW .

http://www.hexcel.com/products/indus...exmc-materials

There is a chart there which shows Hexmc as being a bit stiffer than

Steel and about half the weight of aluminum. And slightly lighter
than Magnesium.

Dan

Specific Tensile Modulus appears to be the ratio of weight to
stiffness. Notice how similar the metals are despite their greatly
differing densities. All four plus wood are suitable for aircraft.

-jsw

On Sunday, May 24, 2015 at 6:45:14 PM UTC-4, Jim Wilkins wrote:

Specific Tensile Modulus appears to be the ratio of weight to
stiffness. Notice how similar the metals are despite their greatly
differing densities. All four plus wood are suitable for aircraft.

-jsw

You are correct. I should have paid more attention.

Dan

On Sun, 24 May 2015 17:13:55 -0700 (PDT), "
wrote:

On Sunday, May 24, 2015 at 6:45:14 PM UTC-4, Jim Wilkins wrote:

Specific Tensile Modulus appears to be the ratio of weight to
stiffness. Notice how similar the metals are despite their greatly
differing densities. All four plus wood are suitable for aircraft.

-jsw

You are correct. I should have paid more attention.

Dan

That's very interesting and versatile material -- almost everything
that Hexcel makes is top-notch -- but it's a pseudo-random-fiber
prepreg mat. The modulus of a unidirectional carbon/epoxy composite is
2 to 2.5 times greater but only in the direction of the fibers.

It's difficult to get the theoretical strength and stiffness with
unidirectional fibers. The layup has to be carefully engineered. This
Hexcel material has the same strength in all directions, which makes
it a *lot* easier to use.

--
Ed Huntress

On Sunday, May 24, 2015 at 8:40:04 PM UTC-4, Ed Huntress wrote:




It's difficult to get the theoretical strength and stiffness with
unidirectional fibers. The layup has to be carefully engineered. This
Hexcel material has the same strength in all directions, which makes
it a *lot* easier to use.

--
Ed Huntress

The other thing that caught my attention is that the part can be removed from the mold while still hot. So suited for production parts.

Disclaimer. I own some Hexcel stock.

Dan