Composites Test 1

  1. Define Composites
    -Combination of at least two components, a matrix/ reinforcements. 

    -This combination creates a material that has properties greater than or equal to the sum of the parts.
  2. Isotropic vs. Anitropic
    -Isotropic: Strength is the same in all directions. 

    -Anitropic: Strength is greatest in a certain direction.
  3. Natural and Synthetic composites
    -Natural: Trees

    -Synthetic: Plie wood, Carbon Fibers (man made)
  4. Classification of Composites
    Fiberous: Reinforced Plastics 

    Laminar: Composed of layers or piles of matrix

    Particulate: Particles dispersed in the matrix
  5. Define Matrix
    -Binder to the reinforcer 

    -Transfer loads across the structure

    -Protects the reinforcement from outside environment

  6. Major classes of Matrices



  7. Considerations in determining proper matrix 


    Design criteria 

    Bond well with reinforcements 
  8. Sources of matrix 

    Natural/ Agricultural 

  9. Define Precursor 
    Starting material that is changed into a new material by means of further processing and use of additives.

  10. Use of Thermoplastic polymers 
    Ceramic Composites: Very brittle, high temperature resistant material. Can be the matrix only but in many cases is both the matrix and the reinforcer.
  11. Use of Thermoset Polymers 
    Melamine-Phenolic: Produced by combining a one-stage phenolic with melamine resin, not used for large volume applications and are generally produced in black or dark colors.  
  12. Co-polymer vs. Alloy
    Co-polymer: The combination of two or more monomers 

    Alloy: The combination of two or more basic polymers into a mechanical mix
  13. Various Thermoset polymers used in composites 
  14. Advantages of Thermoplastics in composites
    -Ease of repairability 

    -Improved impact strength 


    -No need to refrigerate

    -Much quicker processing time 
  15. Disadvantages of Thermoplastics in composites 
    -Overall lower high temperature properties 

    -Still some problems with fiber adherence 

    -Higher material cost

    -Lack of tacticity/ flexibility in prepreg from
  16. Advantages of Thermosets in composites 
    -Higher temperature properties 

    -Lower material cost 

    -Good fiber adherence 

    -Better tacticity/ flexibility  
  17. Disadvantages of Thermosets in composites 
    -Lower impact strength 

    -More difficult to repair 

    -Have to refrigerate 

    -Longer processing time 

    -Hard to recycle 
  18. Four methods of impregnating reinforcement to make prepreg
    -Solvent system 

    -Hot melt

    -Powder Technology 

    -Co-mingled Fiber
Card Set
Composites Test 1
questions for first composites test