7 Aircraft Structural Materials

Question 1

1. How do you work harden a piece of metal?

Answer 1

By cold working the metal.

Question 2

2. Describe the primary difference between a thermosetting and a thermoplastic resin.

Answer 2

A thermosetting resin doesn’t soften when heated and chars or burns rather than melting. Thermoplastic resins become soft and pliable when heated, and harden when cooled.

Question 3

3. Explain how thermoplastic and thermosetting resins are commonly used in modern aircraft.

Answer 3

Plexiglass is a thermoplastic resin commonly used for windshields and windows. Thermosetting resins are most often used as the matrix material in composite structures.

Question 4

4. Name one of the types of resin commonly used as a matrix material for aircraft composite laminates.

Answer 4

Polyester resin or Epoxy resin.

Question 5

5. What are some of the materials that are commonly used as the reinforcing component in a composite structure?

Answer 5

Fiberglass, Aramid (Kevlar), Graphite (Carbon) fiber, linen and paper.

Question 6

6. What are the reasons that alloy steel that is responsive to heat treatment is usually less suitable for welding?

Answer 6

It may become brittle and lose its ductility in the area of the weld.

Question 7

7. Give one advantage of pre-preg materials, other than saving time in the construction or repair of composite components.

Answer 7

1. Pre-preg fabrics contain the correct amount of matrix.
2. The matrix material evenly and completely permeates the reinforcing fibers.
3. The matrix has the resin and hardener in the correct proportions.