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Carlos
11-04-2000, 12:00 AM
Definitions:



"Metal Matrix Composite (MMC): a composite material in which one constituent is a metal or alloy forming at least one percolating network. The other constituent is embedded in this metal matrix and usually serves as reinforcement."



"Metal matrix: the percolating metal or alloy forming the constituent of a MMC in which the other constituents are embedded."





An Intro:



http://www.bebop.com/mmc.htm



Metal Matrix Composites unlike plastic, phenolic, and epoxy based laminates, use a metal base that is reinforced with continous woven fibers (CFRM), short filaments (SFRM), or particles (PRM) of carbon, glass, or other metals. For instance imagine a laminate of continuously woven carbon fibre cloth in an aluminum matrix, or the same instead in a magnesium matrix. The idea is that you get the advantages of the rigidity of the the ceramic fibers, as well as that of the light ductile metals used as a base (al, mg, or ti). Fiber content seems to vary from 25% up to 60%.



I am no engineer, but in the case of CFRM (Continuous Fiber MMC), the reinforced Al-based MMC seems to be twice as strong as pure Al.



"DRA [disconinuously reinforced aluminum] materials have the potential for redefining the limits of aluminum materials because of their unique combinations of properties---the stiffness of titanium, better wear resistance than steel, and tailorable coefficient of thermal expansion, all while maintaining the light weight characteristics of aluminum. These properties, combined with continued development of low-cost processing methods, offer the potential for significantly expanded use." http://www.almmc.com/





My thoughts:



Like the CPM steels, its primary disadvantage seems to be the difficulty in machining it. Otherwise, it seems like the ultimate stuff for handle scales, backspacers, and perhaps even lock mechanisms. For the truly radical, one could even try making knife blades of the stuff.



MMC handles won't be any lighter than the metal matrix they are based on, so the crown of lightness remains with G10 and carbon fiber. But an aluminum-based MMC might make the ultimate meeting of light weight, strength, and toughness for using knives.



What do ya'll think?

sal
11-05-2000, 10:57 AM
Sounds like it's worth checking out. Thanx for the input.

sal

Carlos
11-05-2000, 06:06 PM
Hi Sal,

I know that you are a technology guy, and I knew that there was something that I'd forgotten to mention in our composite handle discussion of last week.

I first heard of MMC from the RACECAR Enginneering journal (it cost something like $10 per issue so I've since stopped reading it). It was being promoted as a replacement for carbon/carbon brakes. While aluminum does weigh a bit more than carbon fiber, the ALMMC offered superior performance at a much lower cost.

I hope it will be a useful technology for Spyderco.

sal
11-05-2000, 10:10 PM
Carlos. Lotus cars in england are using the aluminum composites for the brakes in the new "Elise".

sal

Carlos
11-05-2000, 10:23 PM
Hi Sal,

I love that car. I wish they were importing it into the US in other than the (non-street legal) race trim.

Actually Lotus and Spyderco have similar engineering philosphies: &quot;Light, stiff, and fast.&quot; <img src="smile.gif" width=15 height=15 align=middle>

-- Carlos

Brad Beckmeyer
11-12-2000, 05:48 PM
Knives cut things!

tortoise
11-12-2000, 09:26 PM
Sal,
You were talking about this at the NY show, so when I got home I read Carlos' post straightaway. This sounds just like the metal matrix used in my mountain bike frame (Specialized.) I'm not sure if any of the other companies use the process but it seems likely that they do. Since CO is known for mountain biking, might there be any leads in that direction?
Doug

Carlos
11-13-2000, 01:33 AM
Doug,

What did Sal say? (I knew I would be missing out on interesting stuff at the NYC show. <img src="sad.gif" width=15 height=15 align=middle> )

tortoise
11-13-2000, 09:22 AM
Carlos,
Actually we talked about you by name. Sal told me about his trip to Lotus and his interest in this metal matrix process and the new way of bonding (glueing) components together. I told him my VW was bonded together instead of welded. We all know he loves weight savings. That's why I hit this forum as soon as I got home. Sal said he plans to use it for just this type of discourse, to find out from the &quot;tech junkies&quot; just what might be out there that fits his lighter, stronger, faster creed. When you talk to him you can see how Sal's mind is constantly working. He gets excited about new ideas and more so about teaching others how things work. Very cool.
By the way, I got to handle the ATR, wow!

Edited by - tortoise on 11/13/00 2:43:14 PM

Carlos
11-13-2000, 09:47 AM
Thanks Doug, I wish I could have been there.

I'd really like to see how Sal and his R&amp;D team apply these and other new materials to real world products. I'll definitely keep my eye out for other interesting technological goodies that might help to advance the evolution of our Spyders. <img src="smile.gif" width=15 height=15 align=middle>