MSE227-Chapter15-Spring 2010

MSE227-Chapter15-Spring 2010 - MSE 227Chapter 15 Composites...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Composites 1 MSE 227- Chapter 15
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
ISSUES TO ADDRESS. .. What are the classes and types of composites ? 1 Why are composites used instead of metals, ceramics, or polymers? What are some typical applications?
Background image of page 2
2 Phase types: -- Matrix - is continuous -- Dispersed - is discontinuous and surrounded by matrix non-continuous phase is also called the reinforcement. Composites Multiphase material with significant proportions of each phase. Combination of two or more materials that are mechanically bonded together. The resulting material has characteristics that are different than the components in isolation.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4 Composite properties are function of: Properties of constituent phases Relative amount of phases Geometry of dispersed phase Characteristics of dispersed phase that influence the properties of composites: Composite Phases a- concentration b- size c- shape d- distribution e- orientation
Background image of page 4
Why use composites ? 5 Comparison of different material characteristics: Composites provide the advantages of lower weight, greater strength and higher stiffness
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6 Composites types are designated by: Matrix material Ceramic Matrix Composite (CMC) Metal Matrix Composite (MMC) Polymer Matrix Composite (PMC) Reinforcement Particles The dispersed phase is equiaxed. Fibers The dispersed phase has large length to diameter ratio Structural Composed of 2-dimensional sheets or panel of different materials in forms of laminar or sandwich. Classification
Background image of page 6
Older Technology The concept of composite materials is ancient. An example is adding straw to mud for building stronger mud walls Other common composites: Concrete : cement mixed with sand and aggregate Reinforced concrete : steel rebar in concrete Fiberglass : glass strands in a resin matrix
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Large- Particle Composites The particle diameter : few microns. Particles restrain the movement of matrix phase. Particles carry a major portion of the load. The particles are used to increase the modulus and decrease the ductility of the matrix. Particle reinforced composites are much easier to make and less costly than fiber reinforced composites . For PMCs, particles are added to the melt in an extruder or injection molder during polymer processing. For MMCs, reinforcing particles are added to a molten metal before it is cast . 8
Background image of page 8
Strengthened Composites Particles size: 10 to 100 nm in diameter. Particles help the matrix resist deformation to make the material harder and stronger. Similar mechanism as precipitation hardening : interfere with dislocation movement (recall Chapter 9) Matrix bears the major portion of load Particles like oxides do not react with the matrix or go into solution at high temperatures so the strengthening action is retained at elevated temperatures. 9
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 40

MSE227-Chapter15-Spring 2010 - MSE 227Chapter 15 Composites...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online