Seminar on manufacturing of composite materials


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Seminar on manufacturing of composite materials

  1. 1. Seminar on Manufacturing of composite material under guidance ofProf. Dr. I. Basak Raghvendra Kumar Pandey 10/ME/123 NIT Durgapur
  2. 2. Composite materials:▪ A microscopic mixture of two or more different materials. One typically being the continuous phase (matrix), and the other being the discontinuous phase (reinforcement). ▪ Its properties are strongly dependent on the composite structure. 21-Feb-14 Ceramic fiber composite Polymer matrix composite 2
  3. 3. Why Composites? ▪ Composites can be very strong and stiff, yet very light in weight, so ratios of strength-to-weight and stiffness-to-weight are several times greater than steel or aluminium. ▪ Reduces maintenance costs ▪ Reduces or eliminates corrosion ▪ Better fatigue resistance ▪ Less thermal expansion ▪ Enhanced properties via tailor able properties – Mechanical Composite Steel - Electrical ▪ Reduces cost 21-Feb-14 Aluminium Other Boeing 787 Composite Usage 3 Titanium
  4. 4. Types of composites:Fiber Metal matrix composites classification MMCs • Ceramics + metals • For example cemented carbides and other cermet's • Aluminium or magnesium reinforced by strong, high stiffness fibers Filled particle composites Laminar Flakes Ceramic Matrix Composites CMCs • A ceramic primary phase imbedded with a secondary phase, which usually consists of fibers • Least common composite matrix • Aluminium oxide and silicon carbide are materials that can be imbedded with fibers for improved properties, especially in high temperature applications Polymer Matrix Composites PMCs • Thermosetting resins are the most widely used polymers in PMCs. • Epoxy and polyester are commonly mixed with fiber reinforcement 21-Feb-14 4
  5. 5. Forms the matrix within which the secondary phase is imbedded Matrix material function:A. B. C. D. E. F. Provides the bulk form of the part or product Holds the imbedded phase in place Shares the load with the secondary phase Polymer e.g. PEEK, Polyester, polyurethane, Rubber Metal e.g. Al, Cu, Ti, Ni Ceramic e.g. cements, glass. primary Any of three basic material types: polymers, metals, or ceramics Referred to as the imbedded phase or called the reinforcing agent composite Can be one of the three basic materials or an element such as Reinforcement:1. Rovings Secondary carbon or boron continuous bulk Serves to strengthen the composite
  6. 6. Continuous strand mat Surface veils Chopped strand mat Photomicrograph (about 1500X) of cemented carbide with 85% WC and 15% Co 21-Feb-14 6
  7. 7. Laminated composite MMCs Fiber reinforced polymer matrix CMCs 21-Feb-14 7
  8. 8. Rule of mixture ▪ For particulate composites, the rule of mixtures predicts the density of the composite as well as other properties (although other properties may vary depending on how the dispersed phase is arranged) ▪ Density, r, is given as a fraction, f, as: rc  fm rm  f f r f Note that f m  1  f f Where the subscripts m and f refer to the matrix and fiber. 21-Feb-14 8
  9. 9.  For fiber reinforced composites, the rule of mixtures predicts the density of the composite as well as electrical and thermal conductivity along the direction of the fibers if they are continuous and unidirectional. Density, r, is given as a fraction, f, as: rc  fm rm  f f r f Note that f m  1  f f For thermal conductivity: K c  fm K m  f f K For electrical conductivity: f  c  f m m  f f f  Thermal and electrical energy can be transferred through the composite at a rate that is proportional to the volume fraction, f of the conductive material 21-Feb-14 9
  10. 10. 21-Feb-14 10
  11. 11.  Bulk of energy transferred through matrix  But , in the fiber (polymer) composite, bulk energy transferred through fibers.  When the fibers are not continuous or unidirectional, the simple rule of mixtures may not apply.  For example, in a metal fiber-polymer matrix composite, electrical conductivity would be low and would depend on the length of the fibers, the volume fraction of fibers and how often the fibers touch one another. 21-Feb-14 11
  12. 12. Manufacturing methods 1) Hand lay up 2) Pre- preg forming 3) Pressure moulding 4) Vacuum bagging 5) Filament winding 6) pultrusion 7) Spray method 8) Sheet moulding 9) Bulk moulding 10) Resin transfer moulding 21-Feb-14 12
  13. 13. 1) Hand lay up  Low cost tools  Versatile: wide range of product  Time consuming  Possibility of trap of air bubble  inconsistance 21-Feb-14 13
  14. 14. 2) Prepreg forming  orientation of fibers can be changed  consistent  high productivity  continuous process needs more customers  limited shelf life  delamination 21-Feb-14 14
  15. 15. 3) Pressure forming  Advantages:  wide range of shapes  integrate parts  Consistency  structural stability  relatively simple  Disadvantages  high cost of machine  expensive molds (strong materials required)  no intricate parts 21-Feb-14 15
  16. 16. 4) Vacuum bagging  Advantages:  simple design  any fiber/matrix combination  better quality for the cost  Disadvantages  cannot be heated up too much  breeder clothe has to be replaced frequently  low pressure (760 mm Hg the most)  slowest speed  inconsistency 21-Feb-14 16
  17. 17. 5) pultrusion  Advantages:  Automated processes.  High speed.  Versatile cross-sectional shape.  Continuous reinforcement  Disadvantage :  Die can be easily messed up.  Expensive die.  Mainly thermoset matrix. 21-Feb-14 17
  18. 18. 6) Spray method: Advantages :  Continuous process  Any materials can be used as mold.  Error can be corrected by re-spraying.  Disadvantages :  Slow.  inconsistency.  No control of fiber orientation.  Only one side finished.  Environmental unfriendly. 21-Feb-14 18
  19. 19. 7) Sheet moulding: Advantages High productivity thus inexpensive consistency Disadvantages low volume fraction. Only board can be made. 21-Feb-14 19
  20. 20. 8) Bulk moulding Advantages Highest volume fraction for short fiber reinforced composites (50%) Good mechanical properties Finish can be applied Inserts and attachments possible Disadvantages High temperature and high pressure Random fiber orientation Cannot be used for intricate parts 21-Feb-14 20
  21. 21. 9) Resin transfer method: Advantages  good surface finish on both sides  accurate fiber management is achievable  Ability to build-in fiber volume fraction loadings up to 65%  Uniformity of thickness and fiber loading, uniform shrinkage  Inserts may be incorporated into moldings  Tooling costs comparatively low  Uses only low pressure injection  Low volatile emission during processing  Ability to produce near net shape moldings  Process can be automated, resulting in higher production rates  Ability to mould complex structural and hollow shapes  Low resultant voids  Ability to achieve from 0.5mm to 90mm laminate thickness 21-Feb-14 21
  22. 22. conclusion ...And Just what is composite?? Let’s keep It simple  ▪ A macroscale material “composed” of multiple non homogenious material ▪ More simpler definition ?? Okay... ▪ Its STRING and GLUE ..!! ▪ Its everywhere...starting from MANGALYAAN to an OPERATION theater in hospital. ▪ Why don’t customize the existing design when you have composite ...!!! 21-Feb-14 22
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