50
2
2.3.6 Corrosion Resistance
Chemical plant linings, oil industry components of pipes and ducts,
chimneys, grid flooring, staging and walkways, pressure vessels,
processing tanks and vessels, fume hoods, scrubbers and cooling
tower components, assemblies, enclosures, etc. are often made out
of polymeric composites. Resistance to seawater corrosion is an
important property of composites. Japan has developed a CFRP
propeller for the 499-gigaton merchant vessel shown in . Fig. 2.23.
2.3.7 Defence
Airframes, rocket motor liners, satellite components, enclosures
and containers, personnel armour, shipping and transit containers,
simulators, etc. are made out of composites. Light combat aircraft
(LCA) is developed by India and contains more than 40% of the
structural components—by weight—made out of composites. The
wings, vertical tail, and control surfaces of the LCA are made of
CFRP. In an advanced light helicopter (ALH), the nose is made out
of Kevlar-reinforced composites and the tail section made out of
CFRP.  The LCA-Tejas and ALH-Rudra are shown in . Fig.  2.24.
The rotor hub, cockpit, and main and tail rotor blades are made of
carbon fibre-reinforced composites.
The extent of composites used in the structure is about 60% by
area and about 29% by weight.
2.3.8 Marine
Composites are abundantly used in the marine industry. The
major applications of composites are in hulls of boats and yachts;
. Fig. 2.23 Composite propeller for a merchant vessel [42]
Chapter 2 · Advantages and Applications of Polymeric Composites