Читать книгу Metal Oxide Nanocomposites - Группа авторов - Страница 68

Composites are generally utilized in applications which demands for light weight and high performance. Following are their advantages over traditional materials:

1 1. Composite materials possesses the part integration capabilities which otherwise not possible in metallic counterparts which can be replaced by a single composite component.

2 2. Composite materials exhibit high specific stiffness due to which they are almost one fifth and one half lighter than the weight of steel and aluminum, respectively.

3 3. Composite structures can act as “smart” materials wherein the embedded sensors can monitor the online processes. Such smart composites are generally used to monitor fatigue damage in aircraft structures.

4 4. The composite material possess high specific strength (strength-to-density ratio), which enables the airplanes and automobiles to move faster and with better fuel efficiency.

5 5. Composite materials offer many options of design flexibility and good dimensional stability due to its lower coefficient of thermal expansion (CTE) than metals. For example, the CTE of composites can tuned to zero by selecting suitable materials and lay-up sequence.

6 6. Unlike metals (iron or aluminium), the composites offer high corrosion resistance and does not require special coatings or alloying.

7 7. The composite materials also exhibit high fatigue strength (endurance limit) e.g. the unidirectional carbon/epoxy composite possesses a fatigue strength of ~90% whereas the steel and aluminum alloys fatigue strength only up to ~50% of their static strength.

8 8. Composite materials can easily produce net-shape components thereby eliminating several machining operations and reducing the process cycle time and cost.

9 9. Composite materials can also be utilized in the facile fabrication of complex parts which does not require process of welding or riveting separate pieces, as needed for metals.

10 10. Composite materials can be easily manufactured and assembled which not only minimizes the number of parts in a product but also reduces the assembly and joining time. This in-turn reduces the overall cost.

11 11. Glass-reinforced and aramid-reinforced phenolic composites are utilized in designing aircraft interior panels due to their low smoke and toxicity.

12 12. Composite materials reduce the vibrations to one order of magnitude better than metals and so utilized in airplane and golf clubs.

13 13. By changing the fiber orientation, fiber type, and/or resin systems, the design of the composites can be easily tailored.

14 14. The processing cost of tooling in composites is much lower than that for metals because of lower pressure and temperature requirements.