MEPX
Chapter 8 of 10All chapters
  1. 1Describing a material
  2. 2Structure decides behaviour
  3. 3Metals
  4. 4Ceramics and polymers
  5. 5Composites
  6. 6How materials fail
  7. 7Processing changes properties
  8. 8Choosing a material
  9. 9Modern materials
  10. 10Materials and sustainability

Chapter 8 of 10

Choosing a material

The engineering decision.

The constraints

Required properties, cost per unit and per kilogram, available shapes, manufacturing route, environment, lifetime and disposal. The best material on one axis is rarely the right answer.

  • Specific strength, meaning strength per weight, decides aerospace choices.
  • Availability and lead time defeat many technically superior options.

Selection charts

Plotting one property against another shows which families can even reach a target, before cost narrows it further. It turns a vague search into a bounded one.