COMPOSITE MATERIALS

COMPOSITE MATERIALS

1. A composite material is a combination of two or more materials, is composed by two constituents: the matrix and the reinforcement. This combination allows to have optimum strength and stiffness, lighter weight, and corrosion resistance, these are its main advantages.most of the composite materials, the reinforcement is stronger, harder and stiffer than the matrix. In this combination each material conserves its properties, chemical, physical and mechanical.

   • Particle-reinforced
     • The particles doesn't have a determined orientation, they cause minimal improvements in the mechanical properties.Their dimentions are approximately equal in all directions. Particulate composites tend to be much weaker and less stiff than fiber composites. The particles are also used to reduce the cost of the material.
       • Whysker-reinforced
         • The whiskers are like crystals, they are very strong and when they are treated to be dispersed in the matrix is to difficult to do it uniformly. Their length and diameter are smaller compared to fibers.
       • Large particle
         • The physical properties tend to be isotropic, and as the particle volume fraction increases, the mechanicl properties are improved.
       • Dispersion-strengthened
         • The basic parameters that decide the strengthening are the mean free path in the matrix, it is retained at elevated temperatures, this to avoid that the particles reacting with the matrix.
       • Particle-strengthened
         • The particles in particulate are larger than the dispersion-strengthened, as the particle size increases it will have higher interparticle spacing, and it produces losses in yield strength of the composite.
   • Fiber-reinforced
     • The fibers have a very long axis compared with the particles, they are produced and sold in many directions, they are significantly stronger in the long direction. The fibers can be considered as a type of configuration that has a long axis so much greater than its diameter.
       • Continuous
         • This type of fiber are more larger than the discontiuous, they are also called, algined fibers, they are used when is necessesary to obtain a higher strength and stifness
       • Discontinuous
         • Also callled short fibers, they are normally random aligned, it reduces so muh the strength of the material,but their cost is lower than an algned fiber.
         • Aligned
           • The short fibers also can be aligned but in practice it is difficult to maintain a good alignment with this short fibers.
       • Today, the fiber-reinforced composites are so used in aeronautics, in military as comercial aircrafts, specially carbon fiber- epoxy. that is used mainly in the wings, fuselage and empenage components
   • Structural
     • Laminated
       • Normally the fiber-reinforced composites are of this estructure, the composite is laminated when the lays are stacked at difeferent angles. The cost of the manufacturing of laminated structures is high, because the hand labor is complex and it need much autoclave process.
         • BIBLIOGRAPHY:
           • F. C. Campbell, Structural composite materials. New York, NY, United States: ASM International, 2010.
             • M. Kutz, Ed., Handbook of materials selection. New York, NY: John Wiley & Sons, 2002
               • I. M. Daniel, E. E. Gdoutos, and Y. Rajapakse, Eds., Major accomplishments in composite materials and sandwich structures: An anthology of ONR sponsored research. Netherlands: Springer, 2009
                 • P. K. K. Mallick, Fiber-reinforced composites: Materials, manufacturing, and design, 3rd ed. Boca Raton, United States: Boca Raton, Florida, 2007.
     • Sandwich panels
       • They are formed by two thin layers, and a core material, the two layers are thing but stiff, and the core aterial is between those two layers, this material is normally low strength, but its high thickness makes the sandwich have high bending stiffness with low density. The sanwich panels composites offer high resistance to high velocity impacts.

2. ACT. 1 – COMPOSITE MATERIALS DIAGRAM - ANGEL TEODORO RODRÍGUEZ AMBRÍZ – 1587106 – MIÉRCOLES N2-N4