Chapter 13: Composites

Question 1

The supposition, often valid, that new properties, better properties, better property combinations, and/or a higher level of properties can be fashioned by the judicious combination of two or more distinct materials.

Answer 1

Principle of Combined Action

Question 2

The phase in a composite or two-phase alloy microstructure that is continuous or completely surrounds the other (or dispersed) phase.

Answer 2

Matrix Phase

Question 3

For composites and some two-phase alloys, the discontinuous phase surrounded by the matrix phase

Answer 3

Dispersed Phase

Question 4

The Upper bound of a large-particle composite’s modulus of elasticity is equal to ———.

• Em+ Ep
• EmVm + EpVp
• (EmVm)/((VmEp)+(VpEm))

Answer 4

EmVm+EpVp

Question 5

A ferment is a group of composites that combines a ———and a ———.

• Metal, polymer
• Ceramic, metal
• Ceramic, polymer

Answer 5

Ceramic, Polymer

Question 6

Small carbon black particles are used to reinforce modern rubber because carbon black has a———than reinforcing materials.

• higher tensile strength
• higher modulus of elasticity
• stronger adhesive bond

Answer 6

Stronger adhesive bond

Question 7

A composite in which the dispersed phase is in the form of a fiber (I.e., a filament that has a large length-to-diameter ratio).

Answer 7

Fiber-reinforced Composite

Question 8

The ratio of tensile strength to specific gravity for a material

Answer 8

Specific Strength

Question 9

The ratio of elastic modulus to specific gravity for a material.

Answer 9

Specific Modulus (specific Stiffness)

Question 10

A type of particle-reinforced composite in which particle-matrix interactions cannot be treated on atomic level; the particles reinforce the matrix phase

Answer 10

Large-Particle Composite

Question 11

A means of strengthening materials in which very small particles (usually 0.1 um) of a hard, inert phase are uniformly dispersed within a load-bearing matrix phase.

Answer 11

Dispersion Strengthening

Question 12

The properties of a multiphase alloy or composite material are a weighted average (usually on the basis of volume) of the properties of the individual constituents

Answer 12

Rule of Mixtures

Question 13

A composite materials. The most common ferments are the cemented carbides, composed of an extremely hard ceramic bonded together by a ductile metal such as cobalt/Nickel

Answer 13

Cermet

Question 14

A composite material consisting of aggregate particles bound together in a solid body by a cement

Answer 14

Concrete

Question 15

Concrete that’s reinforced (or strengthened in tension) by the incorporation of steel rods, wires, or mesh

Answer 15

Reinforced Concrete

Question 16

Concrete into which compressive stresses have been introduced using steel wires or rods.

Answer 16

Prestressed Concrete

Question 17

The lengthwise dimension. For a rod or fiber, in the direction of the long axis

Answer 17

Longitudinal Direction

Question 18

A direction that crosses (usually perpendicularly) the longitudinal or lengthwise direction

Answer 18

Transverse Direction