Originally Posted by
jleslie
The metal matrix composite (MMC) described in the post above is aluminum with short ceramic, not carbon, fibers within the metal.
A noteworthy point and, to be frank, I'm not even sure the boron carbide particles could could be classified as a fiber by the time everything is reduced to something that resembles Nestle's Quik.
For those who are interested, here's Griffen's description of their MMC...
Originally Posted by griffenbikes.com
In the late sixties, the government gave UCLA research labs a grant to develop a material that would replace aluminum. The material needed to be stiffer and stronger than aluminum, lighter than aluminum with no fatigue life. To achieve these results they developed a material - boron carbide ceramic metal matrix. They used boron carbide, the hardest known material next to a diamond. When boron carbide is mixed with aluminum it significantly strengthens and stiffens the aluminum. They also developed a process to make this new material. The process yielded a mechanical bond vs. a chemical bond, which is most commonly used. They mechanically combined aluminum, boron carbide, titanium, nickel zinc and copper. They reduced all elements to a 4 micron dust and then mixed them in a jet mill. This provided a homogeneous mixture of all the elements. They then compressed this mixture using a cold isostatic press to form a powder billet. They made various components from the billet, e.g., seats for the Apache helicopter. Griffen takes the billet and extrudes it to make tubing.