Aluminium extrusions are today extensively used in the superstructures of ships. Extruded aluminium profiles have become the numero uno choice of the ship designers who want to increase the above waterline size of a vessel but bereft of the usual problems associated with stability. In vessels like hovercraft and other surface skimming vessels, like fast catamarans, aluminium has given has weight advantage to enable the marine architects to extract more from the available power. Advantages of Aluminium Extrusion

• One of the primary advantages of aluminium extrusion process is that it can provide complex hollow shapes an essential requirement in challenging marine applications.
  
  
• By making productive use of aluminium extrusion technology, the amount of welding, can be reduced considerably thus achieving quality and cost benefits.
  
  
• Excellent resistance to Sea water.

Extruded Aluminium Profiles Used in Marine Applications
Some of the common extruded profiles used in the marine applications are described here:


Pleasure Boats
Aluminium extrusion is a trusted and reputed name in the boat building industry. Its profiles in the range of structural or decorative application is a common feature in boats. Large boats ranging from 8-foot long to even yachts are increasingly opting for extruded aluminum profiles while selecting structural and trim applications. The versatility of aluminum extrusion are making this choice to be a perfect match among material, manufacturing process and product specifications. The popular extruded profiles used in boat include include trim for windows, doors, hatch covers, windshields, supports for canvas canopies, spray rails, structural I-Beams, keels etc. Let's see what are the attributes of aluminium extruded profiles that are making the boat manufacturers scour for them:

• Light weight
• Excellent corrosion resistance
• Good strength
• A variety of shapes

Mechanical Properties Of Aluminium Extrusion
Mechanical properties of AA6082 T6 alloy, very popular in aluminium extrusion for use in marine applications is described here:

Extruded AA6082 T6
Thickness range (mm)	-5	5-10	10-30
Longitudinal
0.2% Proof stress (Mpa)	260	260	260
UTS (Mpa)	310	310	310
Elongation A5(%)	10	10	10
Transverse with no extrusion weld
0.2% Proof stress (Mpa)	245	245	235
UTS (Mpa)	290	290	280
Elongation A5(%)	8	8	6
Transverse with extrusion weld
0.2% Proof stress (Mpa)	245	245	230
UTS (Mpa)	290	290	260
Elongation A5(%)	5	8	3