White Paper

5000 series vs. 6000 series

aluminum extrusions
Understanding differences and key performance factors
in marine and other military applications

By: Steve Althardt, Taber Extrusions

 White Paper

Taber Extrusions

Extruded profiles in the 5000 series aluminum alloys, primarily 5083, 5086, 5454 and 5456 continue
to be the materials of choice for both naval marine and military vehicle applications. Today, 5000
alloy marine extrusions are specified by naval engineers for above water assemblies to enhance
overall structure integrity, extend service life and reduce overall maintenance costs. Extrusions made
in 5083 alloy also can be processed to a Class 1 armor specification that is used in military vehicle
applications, offering ballistic resistance in critical components.

Taber Extrusions with facilities in Russellville, Arkansas and Gulfport, Mississippi is the only US
domestic extruder to have developed the expertise to meet the stringent technical requirements of
5000 series alloys while maintaining consistent supply for some of the US military’s premier programs
for nearly forty years. Taber casts billet, extrudes and processes all materials domestically to assure
compliance with the Buy American requirements for US military applications. Taber has also received
approval from the American Bureau of Ships (ABS) to directly certify 5083, 5086 and 5454 alloys.

The 5000 series alloys exhibit superior ductility, formability and corrosion resistance with 1mechanical
properties approaching those of 6000 series alloys in T6 tempers. Most marine assemblies are
fabricated using traditional welding processes. As such, the integrity of the structure is only as good
as the strength in the weld affected areas. The 5000 series alloys lose far less strength versus 6000
alloys when subjected to the heat associated with a traditional welding process. The temperatures
produced by traditional welding processes are sufficient to anneal or weaken the extrusions in the
affected areas, in essence making the weld affected areas the “weak link” of the component.

An alloy/temper combination such as 6061-T6 when annealed loses 42% of its ultimate strength and
54% yield strength while a 5000 series alloy/temper combination such as 5083-H111 loses less than
3% ultimate and 33.3% yield strength. This is attributed to the alloy’s high magnesium chemistry
and strain hardened temper versus the heat-treated and artificial age practice requited for T-tempers
associated with 6000 series alloys. In critical areas of a ship that bear heavy loads, shipbuilders have
fabricated large structural shapes by welding cut 5000 aluminum plate into configurations such as
angles, channels, tees and I-beams. Taber Extrusions, by utilizing their 8,600-ton extrusion press can
produced one piece, 5000 alloy extrusions in circle sizes up to 19 inches, eliminating the costs
associated with the welding and fabrication of cut plate. This not only is a cost reduction, but the one
piece extrusion produces a part that is mechanically superior as the extruded section maintains its
properties throughout as opposed to the welded and fabricated sections that exhibit a loss in
properties in the weld affected areas.

5000 series vs. 6000 series aluminum extrusions | Understanding differences and key performance factors in marine and other military applications
By: Steve Althardt, Taber Extrusions
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Taber Extrusions

The charts below compare 6061 and 5083 alloys for loss of mechanical properties in weld affected
areas when using traditional welding processes. Note that 5083 alloy loses less than 3% of its
Ultimate Tensile Strength compared to a 42% drop in 6061 alloy.

6061 ALLOY (values shown are ksi) 5083 ALLOY

Another critical element of naval marine design is service life. Corrosion of materials on vessels in
constant operation in a salt water environment plays a key role in both service life and overall
maintenance costs. 2Marine extrusions made in 5000 series alloys outperform 6000 series in
corrosion resistance by 7% (per ASTM G67) and tested at a full one level higher on exfoliation test
scales (per ASTM G66).

The use of 5000 alloy extrusions in military vehicles, particularly 5083, provides for the production of
vehicles that can move quickly while providing armored protection for the operators. Two all-aluminum
vehicles using 5083 extrusions are the Bradley Fighting Vehicle and the M113 Armored Personnel
Carrier. The M113 was the first vehicle to use aluminum armor that made the vehicle much lighter
and stiffer than earlier vehicles. These vehicles benefit from many of the same attributes of 5000
series extrusions exhibited in marine applications including improved strength in weld affected areas
and corrosive resistance. In addition, some 5083 extrusions are processed to a Class 1 Armor
specification that provides ballistic protection for the vehicle. Class 1 extrusions may be subjected to
ballistic testing to assure compliance with MIL-DTL-46083.

The use of the Friction Stir Welding process has gained in popularity with prime naval marine
contractors. This patented process joins two pieces of metal, butted together, using a spinning tool
run longitudinally in the seam to join them without introducing a third material. This process

5000 series vs. 6000 series aluminum extrusions | Understanding differences and key performance factors in marine and other military applications
By: Steve Althardt, Taber Extrusions
3
 White Paper

Taber Extrusions

generates considerably less heat than the traditional welding processes and as such the metal in the
weld affected zones maintains a higher percentage of the original mechanical properties.
Another positive result is a significant reduction in metal distortion allowing for much tighter tolerances
for flatness across wide assemblies. Taber Extrusions has worked closely with Friction Stir Link
of Brookfield, Wisconsin to develop the use of ultra-wide, integrally stiffened panel sections made
from 5000 series tee extrusions. This material is now in use in new, high-tech ships including the
Littoral Combat Ship (LCS). The smooth, flat surface of the ship’s superstructure, made possible by
using friction stir welded panels, is a key element in the ship’s stealth-like characteristics.

The use of 5000 series alloy extrusions in marine and military vehicle applications offers multiple
advantages over the more common 6000 series soft alloys. Taber Extrusions has focused on the
production of 5000 series alloys and has gained the expertise required to meet the stringent
manufacturing and processing requirements of these alloys. Taber is considered the industry leader
for specialty products, including 5000 series extrusions for use in many major military programs.

1
The chart below lists the Mechanical Properties for 5000 Series Alloys for Extruded Wire, Rod, Bar and Profiles
– per Aluminum Standards and Data 2009.

Mechanical Property Limits - 5000 SERIES ALLOYS - Extruded Wire, Rod, Bar & Profiles
TENSILE STRENGTH - ksi

ULTIMATE YIELD
Alloy/ Specified Elongation
Area
Temper Thickness Percent
min max min max
5083-H111 up thru 5” up thru 32 40 24 12
5083-H112 up thru 5” up thru 32 39 16 12
5083-O up thru 5” up thru 32 39 51 16 14
5086-H111 up thru 5” up thru 32 36 21 12
5086-H112 up thru 5” up thru 32 35 14 12
5086-O up thru 5” up thru 32 35 46 14 14
5454-H111 up thru 5” up thru 32 33 19 12
5454-H112 up thru 5” up thru 32 31 12 12
5454-O up thru 5” up thru 32 31 41 12 14
5456-H111 up thru 5” 42 26 12
5456-H112 up thru 5" 41 19 12
5456-O up thru 5” 41 53 19 14

2
Results shown were from tests conducted by an independent third-party laboratory in which 5083 extrusions were
compared to 6082 extrusions per ASTM G66 and ASTM G67 specifications.

5000 series vs. 6000 series aluminum extrusions | Understanding differences and key performance factors in marine and other military applications
By: Steve Althardt, Taber Extrusions
4
 White Paper

Taber Extrusions

Key Contact:

Steve Althardt
Sales Manager, Taber Extrusions
email: salthardt@taberextrusions.com

5000 series vs. 6000 series aluminum extrusions | Understanding differences and key performance factors in marine and other military applications
By: Steve Althardt, Taber Extrusions
5