In dispersion strengthened materials, small particles on the order of 10-5 mm to 2.5 x 10-4 mm in diameter are added to the matrix material. These particles, up to 15% by volume of the composite, act to help the matrix resist deformation thus making the material harder and stronger. Usually the materials carry the load in this composite. NASA commonly uses this type of composites.
*Particle Strengthened Composites
In particle strengthened materials, small particles on the order of a few microns in diameter are added to the matrix material. Usually, the particles fill in between 20% and 40% of the volume of the composite and carry a major portion of the load. NASA also uses this type of composites.
*Fiber Reinforced Composites
In fiber strengthened materials, graphite fiber on the order of 5 to 7 x 10-3 mm in diameter are added to the matrix material. The fibers, which takes up about 40% to 60% of the composite, is added to increase the load carrying capability of the material.
*Hybrid Composites
Hybrid composite are composite that are a mixture of more than two different types of materials. An example of a hybrid composite would be steel reinforced concrete (which has a mixture of steel, gravel, and cement).
A hybrid fiber based composite could be one that is composed of an epoxy resin, carbon fibers, and glass fibers. A hybrid composite could also be a mixture of particle and fiber reinforcement.
3. Examples of Continuous Fiber Reinforced Composite Materials
There are three categories of continuous fiber reinforced composite materials:
Composites Composed Only of Fibers This type of composite usually has the fibers woven into some cloth type structure. Rather than having the resin hold the fibers together, the nature of the woven pattern holds the fibers together. An example of this type of composite would be the carbon-carbon composite, which is quite expensive and only used in very high temperature applications. This type of composites can also be porous to liquids, thus making it unsuitable for dam structures.
Metal Matrix Composites This type of composite is also used in high temperature applications where a traditional polymeric matrix would not work. One examples of this type would be boron/aluminum.
Polymeric Matrix Composites This type of composite consists of fibers immersed in a polymeric matrix. Polymeric matrix composite is much cheaper than the two fiber composites mentioned above. Within this group there are many different types of resin and types of fibers that could be chosen.
Just for your curiosity, the following are names of some of the recyclable parts of composites
Polyester resin/CaCO3/glass fibre
Phenolic resin/MgO,CaCO3/ glass fibre
Epoxy resin/glass, carbon fibre
Polyester resin/silane bonder/glass fibre
Propylene resin/silane binder/glass fibre
Polyethylene terephthalate resin/glass fibre
Vinylester resin/glass fibre
Section I: Introduction
Section II: Present (YOU ARE CURRENTLY IN THIS SECTION)
Section III: Future
Complete Table of Contents
Reference