Aluminum WELDING.
Section 2.
ED'S MIG EQUIPMENT RECOMMENDATIONS FOR COST
EFFECTIVE
PULSED ALUMINUM
WELDS.
OTC Daihen and Fronius make the best pulsed MIG power sources available for both
stainless and aluminum welds on "thin gage" or "high volume"
applications. The OTC equipment is much lower cost and the most cost effective pulsed MIG equipment. At the time this was written, OTC provided superior pulsed MIG output characteristics than comparative North American pulsed MIG equipment and when I figured I needed electronics as part of a MIG weld, then OTC was my choice..
Note:
For more weld equipment data see weld equipment section. Click here.
ALUMINUM
WELD TIPS AND DATA:
Warning:
To avoid cracks. Mixing alloys as typically occurs in welding dissimilar aluminum
alloys can increase the crack sensitivity. When selecting the aluminum filler
metal, examine the base alloy and filler alloy combination and avoid a final mix
of alloys high in both Mg and Cu content.
Poor
wire feed is the prime cause of wire burn back to the contact tip.
In
contrast to the 5xxx series, the 4xxx filler metals typically have lower ductility
and less shear strength in fillet welds, these wires will also have more wire
feed issues than the same size 5xxx wires.
The
5xxx filler metals provide the highest weld strength for none heat treatable alloys.
Magnesium 0.5 to 3% provides a weld which is crack sensitive. The Al - Mg alloys
with less than 3% Mg can be welded with the Al - Si 4xxx alloys as the magnesium
silicides increase ductility and increase the crack sensitivity.
For
optimum wire feed, use minimum amount of brake on wire spool.
To
feed the soft alum wire, use rigid, hard plastic instead of softer nylon.
For
inlet - outlet guides ensure nylon or teflon is used.
To
minimize the wire tension effects on the soft alum wire, use U groove drive rolls,
with
chamfered edges. Use minimum wire feed tension.
Manual
welding aluminum with a traditional MIG torch and an 0.046 wire, use a conventional
10 foot torch with a plastic liner.
If
a robot is used and the wire feed control is mounted on the robot, a push pull
system is
not necessary if an Alcotech or similar MIG wire controlled tension,
dee-reeler is utilized.
ALUMINUM
WELD TIPS AND DATA:
-
Use
higher flow rates for MIG welding Aluminum 40 - 60 cfhr for argon. For helium
argon mixes, 50 - 100 cuft/hr. If you use an argon flowmeter and a helium mix
and set at 40 cuft an hr you may get 50% more gas than you need. For helium argon
mixes use a flow meter designed for helium.
-
Avoid
rigid clamps on fixtures, use minimum restraint to avoid cracking.
-
With aluminum weld heat buildup in the part is rapid consider your weld sequence
carefully, do the thin
parts or gaps first. Consider the use of heat quench components on your fixtures
in close proximity
to the welds.
Excess
restraint on aluminum fixtured parts can result in longitudinal cracking.
Increasing
the weld size will decrease the opportunity for longitudinal cracks.
To
reduce aluminum transverse cracks reduce weld heat input. Lower parameters and increase
weld travel rates.
To
reduce crater cracks use a back step technique, and with a robot use lower weld
data for the crater fill data.
To
minimize center line cracking ensure sufficient convex fillet throat and use low
voltage.
To
increase weld penetration, increase wire feed rate, use the lowest possible voltage,
lower weld speed.
Weld
technique and craters: With aluminum welding, crater cracking is the cause of
many crack influenced weld / part failures. Crater cracks results from the concave
thin weld ends and the high thermal expansion and contraction of the aluminum
as the weld end cools and tears apart.
Welders should buildup craters
to form a convex or mound shape. As the weld cools, the increased weld mass from
the convex shape of the crater weld will compensate for contraction forces. Use
the crater fill data equipment options, a back step technique or start and stop
the weld at the weld completion.
ALUMINUM
WELD TIPS AND DATA:
Pulsed
MIG is especially suited to aluminum weld applications 0.040 to 0.100. For alum parts Over >4 mm, traditional MIG spray
transfer
should provide superior fusion and less porosity.
In
contrast to MIG welding steels, the pulsed MIG process provides real welding benefits.
The lower, attainable
pulsed spray current reduces weld burn-through and the lower
pulsed current with high conductivity - lower melting temperatures means you can use larger wires. Also with pulse less weld smoke and less ozone is generated
Pulsed
MIG ideal for vert up welds, however with aluminum spray transfer can also be used dor all position welds.
With aluminum avoid
weld weaves use stringer beads for multi-pass welds.
With aluminum use
the largest wire sizes to avoid feed problems. Consider 0.046 the smallest practical alum weld wire.
Wire
sizes smaller than 0.046, < 1.2 mm can cause wire feed problems.
Use
an helium argon mix for alum applications thicker than 6 mm and for applications which require
more weld penetration. Best helium mix, 60 helium 40 argon, Note it's important to
keep sufficient argon for it's cleaning action on the surface alum oxides.
Use
the largest size nozzle to ensure complete gas coverage of the weld.
If
wire burn back - contact tip issues occur, consider using the next size contact tip or drill your tips 0.01
larger than the origional tip bore.
To avoid
robot start issues, run the wire in at a faster wire feed rate than the weld wire
feed rate.
As
aluminum weld starts and weld ends can have lack of weld fusion, its beneficial
to add to the length of the welds and with a robot. At the weld starts,
use seperate wire feed - voltage data and techniques to
deal with these concerns.
When
the aluminum is anodized, silicon in the 4xxx alum wires can make the weld appear
darker. A change to a 5xxx wire will improve the appearance.
.
MORE ALUMINUM
WELD TIPS AND DATA:
Use
Austenitic (300 series) stainless for back up bars or clamp materials close to
the aluminum welds.
>
2XXX
- 7XXX aluminum, watch out for start / stop weld cracks, consider run on run off
tabs.
For
base alloys with sensitivity to hot cracking such as 2xxx, consider 4xxx filler
such as 4145 or 4047. These alloys have a very low weld solidification temperature.
A filler with a very low weld solidification temperature ensures the weld solidifies
last after the base metal has solidified and reached its max
strength.
5XXX
aluminum, max preheat / interpass temp 150F 65C to avoid cracks.
With
aluminum alloys with 3.5 - 5.5 Mg to avoid cracking don't preheat over 250F (120C).
With
aluminum alloys with 3.5 - 5.5 Mg to avoid cracking ensure max interpass temp
is 300F 150C.
The
common 6xxx heat treatable alloys lose approx. half their strength after welding.
Post weld heat treat can improve the strength, if post heat considered ensure
the filler is designed for the heat treatment.
Filler
4643 is for welding 6xxx alloys that require post heat treatment to attain improved
strength.
Filler
5180 is used for the 7xxx series. It responds to heat treatment.
To
lower HAZ cracks, use filler with the same or lower melt temp as base metal.
To
prevent weld cracks, filler should have higher alloy content than the base metal.
4XXX
- 5XXX is more crack sensitive when weld contains 0.5 to 2 % Si - Mg.
On
thin alum sheet ER4047 is an alternative to ER4043.
5XXX
or 6XXX pipe may also use ER5656
5183
or 5556 may be used instead of ER5356.
Don't
use 5356 - 5183 5556 5654 for high temperature applications >150 F as stress
corrosion cracking can occur. Consider alloy 5554 as
it contains less than 3%
Mg.
Be
aware of trying to repair the none weldable alum grades. Those high cost alum
components found on aircraft, hang gliders, boats or sports equipment etc may
contain exotic alloys that can lead intergranular micro cracks and failure if
heat is applied.
MORE ALUMINUM
WELD TIPS AND DATA:
As
thermal conductivity is very high for alum, the first 1/4 (6 mm) of the weld should
provide a lack of weld fusion concern. That concern is increased when the aluminum
components are >3 mm. The thicker the part, the greater the heat sink. The
lack of weld fusion is typical in the first 6 mm of the weld. If your aluminum
welds are >3mm and subject to stress or fatigue, the following points will
help in improving weld start fusion and weld crater issues. Some
alum weld equipment provides a hot start feature which will enable you to set
more weld current for the start.
With
robots you can increase your arc start times and set a separate, higher weld parameter
weld schedule for the first 6 mm of the weld.
If you need a weld three
inches long on a part subject to stress, the designer would be wise to make the
weld three and a half to four inches long to compensate for weld start / stop
issues.
To
minimize the effects in the aluminum weld crater from the high thermal expansion
and weld shrinkage (5 - 7%), try the following.
If purchasing new MIG
weld equipment ensure it has a a good crater fill feature which lowers the current
in a controlled manner over a minuscule time period at the end of the weld. Those
TIG welders who have used the weld current foot controls to ramp down the weld
current at the crater will be aware of the crater benefits when applied to a MIG
weld.
If your robot weld equipment does not provide the current ramp
down feature, then set a separate weld schedule to commence for the last 6 mm
of the weld. This weld schedule would either provide a lower wire feed and voltage
than the weld , or the schedule would have the same wire feed setting as the weld
with 2 to 6 lower volts than the weld voltage.
If your parameter control
at the crater does not leave a convex weld, use the back step technique in which
you get to the end of the weld and then come back 6mm with a lower parameter setting.
Due
aluminum's higher thermal conductivity, lower melting temperature and lower electrical
resistivity than a steel, the alum MIG wire wire stick out is is extremely sensitive
to current and voltage changes. This is one reason instability issues are a concern
with the pulsed MIG process.
Warning:
To avoid cracks. Mixing alloys as typically occurs in welding dissimilar aluminum
alloys can increase the crack sensitivity. When selecting the aluminum filler
metal, examine the base alloy and filler alloy combination and avoid a final mix
of alloys high in both Mg and Cu content.
IF YOU USE
ROBOTS FOR ALUM WELDS,
ARE YOU AWARE OF THE FOLLOWING?
IF
YOU HAVE A FULL UNDERSTANDING OF ALUMINUM AND ROBOT WELD PROCESS CONTROLS, YOU
COULD USE SEPARATE WELD PARAMETER SCHEDULES IN A SINGLE WELD TO OVERCOME MANY
OF THE UNIQUE ALUMINUM HEAT RELATED WELD AND WELD START ISSUES?
IF THE WELD HEAT IS
BUILDING UP DURING THE WELD, WHEN YOU GET TO THAT POINT USE A SEPARATE, LOWER DATA WELD SCHEDULE.
IF YOU HAVE WELD START
ISSUES, USE A HIGHER WIRE FEED RUN IN WELD SCHEDULE AT THE START.
|
Question from Deborah. Mr. Craig, I am in the process of preparing WPS's for welding Aluminum
Bus ASTM B 236 gr 1350 . As AWS does not list this
material in D1.2, nor does the ASME BPV Section II B I have purchased the Material
Spec from ASTM
My question is in regards to the PQR Test requirements. D1.2
Table 3.4 calls for Tensiles and Side bends. Would the tensile property limits
as set forth in B 236 for the material be the criteria for the weld tests ( PQR
Record)? We will be welding 2" thick members using 1100 filler. Thanks Deborah
Robinson
Ed's Answer: The 1100 filler is a good match for electrical
conductivity, however you will get far better weldability and weld properties
from a 4043 wire for your 1350 aluminum applications. Irrespective of the weld
wire used, as the part is 2 inches thick I would use MIG and use a 60 helium 40
argon mix As for the best weld process of course you can TIG weld with argon but
to speed the job up consider high energy MIG spray transfer, with 045 wire. As
for the procedure set the wire in the spray mode, (data available in this section)
Remember with this applications it's all about attaining consistent weld penetration.
What ever process you use first pre-qualify the weld. You should weld a small
section and cut it and check the weld fusion profile attained. Regards Ed
Question:
Ed when we liquid penetrant the "TIG" aluminum welds, in the heat affected
zone (HAZ), we sometimes see evidence of micro cracks. What
can we we too prevent this?
Ed's
Answer. The micro cracks in the HAZ are frequently caused by excess weld heat
(CURRENT) or by the High Frequency (HF) intensity. A reduction in either the GTAW
weld current, an increase in weld speed, or a reduction in the TIG, HF intensity
should eliminate the micro crack problems in the alum HAZ.
ALUMINUM
WELD TIPS - DATA:
For
optimum aluminum welds, focus on the above "optimum wire feed /amp"
data.
For welding > 1/4 consider the 062 wire with traditional spray transfer. With
regular spray transfer travel speeds much greater than pulsed can be attained,
>50 ipm are attainable. Also from a weld penetration and arc stability perspective
spray can be superior to pulsed.
To
improve weld fusion at arc starts consider these techniques. With manual MIG welding
use a shorter wire stick out and a back hand technique for the weld starts. With
a robot use hot start data, combined with back hand and a shorter WSO at the arc
start.
If
welding less than 3 mm, first choice would be the pulsed process, however short
circuit can also be used.
-
If you use a spool gun or regular MIG gun and you don't know the wire feed setting
you are using, remember, it's important to always be aware of the wire feed rate.
Check the wire feed rate by how much wire comes from the gun in 10 seconds, then
to make weld parameter, wire feed adjustments, adjust the wire feed in increments
of 10%.
Use
the optimum amps for the wire diameter selected. If you are setting pulsed current,
the typical opt pulsed range will be the optimum amps minus approx. 30 - 60 amps.
If welding aluminum vertical up with 0.046 wires and a traditional CV power source
set the vert up welds with a wire feed of 280 ipm (11 o'clock traditional
feeder) 140 amps 23 volts.
If welding short circuit set the weld volts between 14 and 17 volts. Listen to
arc sound, if soft plop sound lower volts till crisp consistent crackle sound,
if harsh crackle with spatter increase weld volts till crisp consistent crackle
sound.
Adjust
the spray arc length with a voltage adjustment so the arc length is at its lowest
and the weld transfers without disrupting the weld causing weld spatter. To
lower the arc length lower the voltage.
ALUMINUM SPRAY TRANSFER MIG WELD DATA:
Weld
Wire Size
|
Spray
Wire Feed
Range
ipm |
Spray
Amps |
Spray
Volts |
Spray
Parameters.
|
0.030
|
500-750 |
95-150 |
22-24 |
Amps
110 -130
Opt Wire feed
500 - 675 ipm
22 volts
|
0.035
(1mm)
|
400-700
|
120-200 |
23-24 |
Amps 150
Opt Wire feed
500 ipm
23 volts
|
|
285-600 |
140-270 |
23-25 |
Amps 170 -230
Opt Wire feed
370 - 450 ipm
24 volts
|
|
220-410 |
190-350 |
26-28 |
Amps 275
Opt Wire Feed
300 ipm
26/27 Volts.
|
To
set an optimum pulsed MIG weld start out with the very low end of the spray recommendations.
Note:
Spray data provided will work as a start point for most alum wire grades. For those one
pound spool guns with vague wire feed settings, measure the wire feed rate as
it exits the gun. For alum welding application, if you don't know the spray or
pulsed weld volts, start at 23 weld volts.
|
.
METRIC
CONVERSION
WIRE FEED inch/min to mm/sec = x 0.42.
.
.
.
ALUMINUM HOW MANY POUNDS OF MIG
WIRE REQUIRED PER WELD SIZE?
Aluminum
1/8 3.2 mm fillet = 0.092 lb/ft 0.03 kg/m
Aluminum
3/16 4.8 mm fillet = 0.026 lb/ft 0.04 kg/m
Aluminum
1/4 6.4 mm fillet = 0.05 lb/ft 0.07 kg/m
Aluminum
3/8 9.5 mm fillet = 0.06 lb/ft 0.09 kg/m
Aluminum
butt weld 13 mm plate 60 degree single V = 0.3 lb/ft 0.43kg/m
Aluminum
butt weld 18 mm plate 60 degree single V = 0.4 lb/ft 0.66kg/m
Aluminum
butt weld 25 mm plate 60 degree single V = 0.82 LB/FT 1.2kg/m
Aluminum
butt weld 38 mm plate 60 degree single V 1.7 lb/ft 2.6 kg/m
Aluminum
butt weld 50 mm plate 60 degre single V 2.8 lb/ft 4.2 kg/m
ALUMINUM
"ipm" FEED RATE TO WELD DEPOSITION RATE:
030
0.8 mmwire, ipm x 0.004 = lb/hr
035
0.9 mmwire, ipm x 0.0056 - l/hr
046
1.2mm wire, ipm x 0.0099 = lb/hr
052
1.4mm wire, ipm x 0.012 = lb/hr
062
1.6mm wire, ipm x 0.017 = lb/hr
093
2.4mm wire, ipm x 0.0415 = lb/hr.
ALUMINUM "m/min"FEED RATE
TO WELD DEPOSITION RATE:
0.8mm
wire, m/min x 0.07 = kg/hr
1
mm wire, m/min x 0.09 = kg/hr
1.2
mm wire, m/min x 0.16 = kg/hr
1.4
mm wire, m/min x 0.23 = kg/hr
1.6
mm wire, m/min x 0.306 = kg/hr
2.4
mm wire, m/min x 0.74 = kg/hr
1990:
A MESSAGE FROM ED TO THE MANUFACTURERS OF ALUM MIG WIRES
1990. For decades Aluminum wire manufacturers have provided 0.035 - 0.046 - 0.062 alum
wires. If the major aluminum weld wire manufacturers employed good weld process control
individuals and employed weld wire marketing managers that actully understood the weld issues that occur with aluminum MIG welds, when the pulsed MIG process
was introduced, they would have developed an 0.052 (1.4mm)
aluminum filler wire.
An 0.052 1.4 mm aluminum MIG wires would be ideal for many, robot, pulsed
automotive applications which to day use the smaller 0.046 wires and have wire
feed and burnback issues. As with many of the MIG issues that face this industry,
this is just another case of process and application apathy / ignorance by the
companies who make weld consusmables. I wonder if there is an aluminum wire marketing
person out that can finally offer the alum welding industry something that will
actually provide practical welding benefits.
.
.
Aluminum Filler Metal Selection |
ALUMINUM
ALLOY
|
FILLER
METAL SELECTION
AWS A5-10. Use first choice. Confirm choice with wire manufacturer
|
Aluminum
2011 / 7075/ 7178 Wrought Alloys
|
Welding not
recommended
|
Aluminum
Casts - 242 / 520 / 535 / 705 / 707 / 710 / 711 / 713 / 771
|
Welding not
recommended
|
Aluminum
1060 to 319- 333 - 354 -355 - 380
|
Use
4145 or 4043
|
Aluminum 1060 to 413
- 443 - 444 - 356 - 357 - 359 -
|
Use 4043 or 4047
|
Aluminum
1060 to 514 / 5454 / 5154 / 5254 /
|
Use 4043 - 5183 - 5356
|
Aluminum
1060 to 7005/7939/712/6070/
5052/5652
|
Use 4043 - 4047
|
Aluminum
1060 to
6061 / 6063 / 6101 /6151
6201/ 6951/
|
Use 4043 - 4047
|
Aluminum
1060 to 5456
5086 / 5083
|
Use 5356 - 4043
|
Aluminum
1060 to 5005
5050 / 1100 / 3003
|
Use 1100 - 4043
|
Aluminum
1060 to 3004
|
Use
4043
|
Aluminum
1060 to 1060
|
Use
1260 - 1060
|
Aluminum 1060 to 2014
/ 2024
|
Use
4145
|
Aluminum 1100 and 3003
to 319 - 333 354 - 355 - 380
|
Use 4145 - 4043
|
Aluminum
1100 and 3003 to 413 - 443 - 44 -356 - 357 - 359 - 6067
|
Use 4043 - 4047
|
Aluminum
1100 and 3003 to 514 - 5545 - 5154- 5254 - 5052 - 5652
|
Use 4043 - 5183
|
Aluminum
1100 and 3003 to 6951
|
Use 4043 4047
|
Aluminum
1100 and 3003 to 1060
|
Use 1260 - 4043
|
Aluminum
1100 and 3003 to 5456 - 5086 - 5083
|
Use 5356 - 4043
|
Aluminum
1100 and 3003 to 2014 - 2024 -2219
|
Use 4145
|
Aluminum
1100 and 3003 to 5005 - 5050 - 3004
|
Use 4043 - 5183
|
Aluminum
1100 and 3003 to 1100 -
3003
|
Use 1100 - 4043
|
|
|
Aluminum
2014 and 2024 to 319 - 33 -354 - 355 - 380
|
Use 4145 - 2319
|
Aluminum
2014 and 2024 to 413 - 443 - 444 - 356 - 357 - 359
|
Use 4145
|
Aluminum
2014 and 2024 to 6067- 6061 - 6063 -6101 - 6151 -6201 -6951
|
Use 4145
|
Aluminum
2014 and 2024 to 2219 - 2014 - 2024 -
|
Use 4145 - 2319
|
Aluminum
2090
|
Use 2319 - 4047- 4145
Note limited crack sensitivity
|
Aluminum 2219 to 319
- 333- 354 - 355 - 380
|
Use 4145 - 2319
|
Aluminum
2219 to 413 - 443 - 444 - 356 - 357 - 359 -
|
Use 4145 - 4043
|
Aluminum
2219 to 514 7005 - 7939 - 712
|
Use 4043 - 4047
|
Aluminum
2219 to 6070 - 6063 - 6101 - 6151 - 6201 - 6951
|
Use 4043 - 4145
|
Aluminum
2219 to 5456 - 5086 -5083
5005 - 5050 3004
|
Use 4043
|
Aluminum
2219 to 5154 - 5254 - 5052
5652
|
Use 4043 - 4047
|
Aluminum
2219 to 2219
|
Use 2319
|
Aluminum
2519 - T87 to 2519 - T87
|
Use 2319
|
Aluminum
2519- T87 to 5083 H131
|
Use 4043
|
Aluminum
5005 - 5050 - 3004 to 319
333 - 354 - 355 - 380
|
Use 4043 - 4047
|
Aluminum
5005 - 5050 3004 to 413 -443 - 444 - 356 - 357 - 359 -
|
Use 4043 - 4047
|
Aluminum
5005 - 5050 3004 to 514 - 5154 - 5254
|
Use 5654 - 5183
|
Aluminum
5005 - 5050 3004 to 7005 - 7939 - 712 - 5083
|
Use 5356 - 5183
|
Aluminum
5005 - 5050 3004 to 6070 - 5052 - 5652 - 5005 - 3004 -
|
Use 4043 - 5183
|
.
Aluminum
5005 - 5050 - 3004 to 6061 - 6101 - 6063 - 6151 - 6201 -6951-
|
Use
4043 - 5183
|
Aluminum
5005 - 5050 - 3004 to 5456 - 5086 - 5083 -
|
Use
5356 - 5183
|
Aluminum
5005 - 5050 - 3004 to 5454 - 5154 - 5254 -
|
Use
5654 - 5183
|
Aluminum
5005 - 5050 - 3004 to 3004
|
Use
4043 - 5183
|
Aluminum
5052 - 5652 to 319 - 333 - 354 - 355 - 380
|
Use
4043 - 4047
|
Aluminum
5052 - 5652 to 413 443 - 444 - 456 - 357 - 359
|
Use
4043 - 5183
|
Aluminum
5052 - 5652 to 514 - 5454 - 5154 - 5254 -
|
Use 5654 - 5183
|
Aluminum
5052 - 5652 to 7005 - 7039 - 712 - 5086 - 5083
|
Use
5356 - 5183
|
Aluminum
5052 - 5652 to 6070 5456
|
Use
5366 - 5188
|
Aluminum
5052 - 5652 to 6061 - 6063 - 6101 - 6151 - 6201 - 6951
|
Use
5356 - 5183
|
Alum 5083 |
Use 5556 - 5183 |
Aluminum
5083 to 413 - 443 - 440 - 356 - 357 - 359 - 514 - 6070 - 5454
|
Use
5356 - 5183
|
Aluminum
5083 to 7005 - 7939 - 712 - 5456 - 5083
|
Use
5183 - 5356
|
Aluminum
5083 to 6061 - 6063 - 6101 -6151 - 6201 -6951
|
Use
5356 - 5183
|
Aluminum
5083 to 5154 - 5254 - 5086
|
Use
5356 - 5183
|
Aluminum
5083 to 5083
|
Use
5183 - 5356
|
Aluminum
5083 to 6070
|
Use
5356 - 5183
|
|
Use 5556 - 5183 |
Aluminum
5086 to 413 - 443 - 440 -356 - 357 - 359
|
Use
5356 - 4043
|
Aluminum
5086 to 514 - 7005 - 7939 - 712 - 6070 - 6061 - 6063 - 6101
|
Use
5356 - 5183
|
Aluminum
5086 to 6151 - 6201 - 6951- 5456 - 5086
|
Use
5356 - 5183
|
Aluminum
5086 to 5454 - 5154 - 5254 -
|
Use 5356 - 5183
|
Aluminum
5154 5254 5454 to 413 - 443 - 444 - 356 - 357 - 359 -
|
Use
4043 - 5183
|
Aluminum
5154 5254 to 514 - 5454 -
|
Use
5654 - 5183
|
Aluminum
5154 -5254 - 5454 to 700 - 7939 - 712 - 6070 - 6061 -6063
|
Use
5356 - 5183
|
Aluminum
5154 -5254 - 5454 to 6101 - 6151 - 6201 - 6951 - 5456 -
|
Use
5356 - 5183
|
Alum 5456 and 5383
|
Use 5556 - 5183 |
Aluminum
5454 to 5454
|
Use
5554 - 4043
|
Aluminum
6061 - 6063 - 6101 - 6201 -6151 - 6951 to 319 - 333 - 354 - 355 - 380 -
|
Use
4145 - 4043
|
Aluminum
6061 - 6063 - 6101 - 6201 -6151 - 6951 to 514 - 7005 - 7939 - 712
|
Use
5356 - 5183
|
Aluminum
6061 to 60XX
|
Use
4043 - 5183
|
Aluminum
7004 to 1060 - 1100 1350 - 3003 -5052 - 5083 - 5086
|
Use
5356
|
Aluminum
7004 to 5454 - 6061 - 6063 - 6351 -7004
|
Use
5356
|
Aluminum
7005 - 7039 - 712 - to 319 - 333 - 3544 - 355 - 380 - 413 - 443 - 444 - 356-79
-
|
Use
4043
|
Aluminum
7005 - 7039 - 712 to 514
|
Use
5356
|
Aluminum
7005 - 7039 - 712 to 7005 7939 - 712
|
Use
5039
|
Aluminum
514 to 413- 443- 444 - 356 - 357 - 359
|
Use
4043 5183
|
Aluminum
514 to 514
|
Use
5654 - 5183
|
Aluminum
413 - 443 - 444 - 356 - to 319 - 333 - 354 - 355 - 380
|
Use
4145 - 4043
|
Aluminum
413 - 443 - 444 - 356 to 413 443 - 4444 - 356 - 357 - 359
|
Use
4043 or same as base
|
Aluminum
356 - 357 - 359 - to 319 - 333 - 354 - 355 - 380
|
Use
4145 or same as base
|
6061-T6 Aluminum Weld Questions:
Question: We weld 6061-T6, with 4043 wire. While trying to
establish the weld procedure qualification for a groove weld, we have been unable
to attain the minimum tensile strength as required by the 97 AWS structural weld
code DI.2-97. The weld integrity appears fine, however the transverse tension
tests are failing in the HAZ, at unacceptable, AWS specified strength loads.
Ed's
reply: This is a common problem
with the heat treatable 6xxx alloys. The lack of acceptable strength in this heat
treated aluminum alloy is usually caused by "weld overheating" of the
base metal. 6061-T6 gets its strength through solution heat treatment and is also artificially
aged. This aluminum alloy is heated to 990F, which dissolves the alloy elements
magnesium and silicon into magnesium sillicide into a super saturated solution.
Quenching in water follows to trap the resulting elements in a supersaturated
solution. The material is then reheated in the 300F range and held for a predetermined
time, (this is aging). The aging is carried out to precipitate some of the compounds
/ elements out of the supersaturated state to improve the mechanical properties.
The 6061-T6 alloy in the unwelded condition will have an approx. tensile strength
of approximately 45 ksi.Welding
disturbs the carefully controlled heat treatment and the 6061-T6 minimum tensile
is reduced to approx. 24 ksi. When welding, multi-pass welds or high weld heat
can dramatically lower the aluminum tensile strength. When welding the 6061 T6
alloys with either 4xxx or 5xxx filler metals, to meet the code, minimum tensile
strength requirements, ensure you comply with the "minimum" base metal
thickness requirements, its beneficial to use a thicker plate as this provides
a greater heat sink for the weld qualification test. Ensure compliance with the
heat treatment and holding time. For info go to the AWS Structural Weld Code.
WELDING
6061-T6, THINK HEAT REDUCTION:
* The MAX preheat and "interpass temp" is 250F,
do not weld on this part till the
temp is below 200F. *
If possible if using fixtures, give consideration to copper components that can
be attached near the weld to act as a "heat sink".
* When
MIG welding use the highest possible weld travel rates with the lowest possible
weld voltage.
* Use stringer beads rather than weaves, the weld speed
will be quicker with stringers.
* Do not use helium in the gas mix, unless
it's essential. .
6061-T6
WELDS AND HEAT.
If welding with 6061-T6, and
the parts are subject to heat consider 5554 / 4047 / 4043 filler. If 5356 / 5556
or 5183 is used sensitization of magnesium in the metals can result in stress
corrosion or part failure.
6061-T6 WELDS AND
COLOR.
If welding with 6061-T6 and this wire is used on parts that
require good color match after anodizing. Consider 5356. MIG wires 4XXX would
after anodizing produce grayish looking welds.
6061-T6
WELDS / STRENGTH and POST WELD HEAT TREATMENT.
If using this 6061-T6 filler
metals to weld critical applications and applications that have multi-pass or
extensive welds in a localized zone, its likely you will require a post weld solution
heat treatment and artificial aging in order to restore the application strength
in the weld proximity and return the application to the -T6 temper properties.
With applications such as this its logical to be concerned about the weld wire
selection and mechanical strength of the "weld" after post weld heat
treatment. Remember that the 5183 - 5356 -5556 filler alloys are non-heat treatable
alloys which can undergo negative changes when subjected to heat treatment. The
4043 filler alloy, is also non-heat treatable, however when this weld has dilution
with the base metal the resulting weld properties can respond to the heat treatment.
Consider for post heat treat applications using the 4643 MIG or TIG wires, as
these weld consumables are heat treatable and can provide a weld of comparable
strength to that of the base material.
6061
WELDS AND CRATER CRACKING.
To
reduce crater cracking with 6061 alloys try welding with 4047 which in contrast
to 4043, the 4047 weld wire freezes more quickly reducing the potential for hot
cracking. Also consider weld equipment that provides a good crater fill program.
6063-T6
TIG Weld Question.
Ed,
we pulsed TIG weld 6063-T6 electronic cabinets. We weld the boxes in the inside
and outside edges and are experience weld cracking. If required we weld with 4043
filler, however when welding the outside welds we use no filler. How can we reduce
the weld cracks.
Ed's reply. The
aluminum magnesium silicon 6xxx alloys are crack sensitive due to the magnesium
silicide. The best way to reduce the TIG weld cracking sensitivity with 6xxx alloys
is to use filler metal. The filler metal will dilute the weld with the magnesium
if 5xxx filler is used , or with silicon if 4xxx filler metals are utilized. If
MIG welding use vee preps or large throat fillet welds to ensure that sufficient
weld filler metal is used.
T6
/ 6063 - T52 MIG Weld Question.
Ed, When welding 6063-T6 to
6063-T52 which alloy will give the best strength. I believe that 4043 has the
least crack sensitivity but the lowest strength, however I don't know the difference
between 5356 and 5556. I need to have the best as-welded strength for minimum
fillet sizes.
Ed's reply. For butt welds
the 4043 and 5556 provide similar results. When using these wires and welding
butt weld on the alloys discussed you would expect the parts to fail in the HAZ
rather than in the welds. For fillet welds on these aluminum alloys go with the
5356 wire, it will provide the strongest fillet welds.
2008:
Question: Ed we
are TIG welding a 6061 fabrication,the parts are 1/8 to 3/8. Most of the welds
are are made with a 5356 wire with the TIG process. The distortions on the fixtured,
clamped parts can be from from 1/16 to 1/4. We are considering changing to pulsed
MIG PROCESS DO YOU SEE THIS AS A SOLUTION. Thanks. Frank Givens.
.
Welding
6061 with MIG or four times slower with TIG and
BELIEVE
IT OR NOT, THE WELD DISTORTION WILL BE SIMILAR, see next photo.
Ed's
Answer to the 6061weld distortion question. There
are a number of issues going on on with your application.
Think about what
that high strength 5053 fillet weld does to that much lower strength, 6 mm, 6061,
6 mm metal during the 5356 weld shrinkage and solidification stage.
I
firmly believed that if I used the pulsed MIG process that welds four times faster
than the TIG process, that irrespective of the metal or filler metal utilized,
the end result had to be less weld distortion. Then I put the weld helmet on and
welded the above parts and my theory was shot to pieces. I tacked some parts on
one side and other parts both sides. Before welding the vertical parts was set
with a square. I then made 4, two inch stitch welds with the pulsed MIG process
on one part and the TIG process was used on the other part for comparison.
The
results led to the conclusion that the amount of weld heat or the weld heat time
really did not matter?
Also
on these parts to minimize hot cracking and reduce weld distortion, I would use
the pulsed MIG process and 4043 filler metal with straight argon. As to minimizing
distortion you will need to use more braces and offset and possibly pre-bend part
to compensate and lets face it, with the time saved from the MIG process, you
can use that time to get the big hammer out and do what many welders do best.
After
welding with TIG and MIG, (part photo above), the weld distortion was the same
on both the tacked
and none tacked parts
6061
AFTER WELDED WITH TIG and MIG 5053.
.
.
Data
on Aluminum Alloys |
Welding is not recommended
on alum casts 242 - 520 - 535 - 705 - 707 - 710 - 711 - 713 - 771, Check filler
recommendations at the bottom of this site with alum wire manufacturer to ensure
color match, crack resistance, strength, ductility, or corrosion resistance. Also
clarify if heat treatment required.
None
Heat Treatable are used in the
strain hardened (WORK HARDENED) condition to improve the alloys mechanical properties.
While welding, the weld heat will return the HAZ to its annealed condition. This
condition typically reduces the strength in the HAZ area.
Heat
Treatable alum alloys are often
in the T-4 or T-6 condition, solution heat treated and naturally aged, or solution
heat treated and artificially aged. These metals after heat treat provide optimum
mechanical properties. Weld heat (time and temperature) will change these properties.
Typically the result of a weld is a partial anneal and an overaging affect.
The bottom line, the reduction in mechanical properties of the heat treated
alum alloys is greatly affected by the "time and temp" of the weld.
Minimum preheat, low weld parameters, welds made at high speeds, stringer rather
than weaves, along with low weld interpass temperatures can minimize the heat
effects, however you will experience a considerable loss in the tensile properties
in the HAZ adjacent the weld.
|
1XXX
Series Aluminum Alloys Min 99% Aluminum. None Heat Treatable. Ultimate tensile
10 - 27 ksi. Selected for superior corrosion resistance. Typically welded with
matching alloy or 4xxx filler.
|
Alloy |
Designation |
Alloy Content / Description |
1XXX
99% min alum. None Heat Treat.
1050
|
UNS
A91050
ASTM B 491
UNI 4507
Italy P-ALP99.5
USA/UK/Japan/ISO/
Germany = Al 99.5
|
99.5%
Alum
|
1050-H16
|
|
Tensile
19 ksi 130 MPa
Yield 18ksi 125 MPa
|
1060
|
UNS
A91060
ASTM B209
SAE J454
AMS 4000
|
99.6%
Alum
Melts 1195F
|
1060-H14
|
|
Tensile
14 ksi
Yield 13 ksi
|
1100
|
UNS
A91100
AMS 4001
ASTM B209
SAE J454
ISO/Germany AL99.0
|
99%
Alum + 0.12 Cu
Melts 1190F
This series used for cooking containers food
and chemical handling
|
1100-H16
|
|
Tensile
21 ksi
Yield 20 ksi
|
1100-O
|
|
Tensile
13 ksi
Yield 5 ksi
|
1XXX
AND 3XXX WELDED WITH ER1XXX POTENTIAL FOR EXCESS POROSITY ON COMPONENTS > 6
mm CONSIDER 60 HELIUM 40 ARGON
|
|
2XXX
Aluminum Alloys Aluminum Copper, Heat Treatable.Ultimate Tensile Strength 27 to 62 ksi.
High strength high performance alloys often used in aero space. Some are none
weldable as susceptibility to hot cracking or stress corrosion cracking. For the
weldable grades these are typically welded with high strength 2xxx filler metals,
or 4xxx
|
2011
|
|
welding
not recommended
|
2014
|
Germany
AlCuSiMn
Italy P-AlCu4.4 Si/Mn/Mg
UNI 3581
|
93.5%
Alum
Si 0.8
Cu 4.4 - Mn 0.8 - Mg 0.5
Melts 950F - 510C
|
2014 -O
|
|
Tensile
27ksi
Yield 14 ksi
|
2014-
T4
|
T-4
or T-6 = solution heat treated and naturally aged or solution heat treated
and artifically aged. Weldiing the
T-4-6 parts effects the mechanical properties.
Typically an anneal and overage effect reducing tensile strength especially in
HAZ.
To minimize erffects
low preheats and low interpass temp
|
Tensile
62 ksi
Yield 42 ksi
|
2024
|
UNS
A92024
AMS 4007
SAE J454
Germany AlCuMg2
Ittaly PAlCu4.5Mn
UNI 3583
|
93.5
Aluminum - Cu4.4
Mg 1.5 - Mn 0.6
Melts 935F 500C
Higher strength
than 1XXX
Used for Aircraft component, hardware, rivets, wheels etc.
NOTE
NOT WELDABLE
if weld susceptable to stress corrosion cracking after welding
that can cause delayed failures.
|
2024-T4 - T351
|
|
Tensile
68 ksi
Yield 47 ksi
|
2024
- O
|
|
Tensile
27 ksi
Yield 11 ksi As this alloy contains a small amount of Mg the hot cracking
potential in the grain boundary area is increased. Use lowest heat input avoid
mult-pass welds.
|
2036
|
UNS
A92036
|
96.7
Aluminum
Cu 2.6 - Mg 0.45 - Mn 0.25
Melts 1030F
|
2036 - T4
|
|
Tensile
49 ksi
Yield 28 ksi
|
2048
|
|
94.8
Alum - Cu 3.3 - Mn 0.4
Mg 1.5
Tensile 66 ksi 455 MPa
Yield 60 ksi
|
2090
|
|
Li
1.9 - 2.6 - Cu 2.4 - 30
Zr 0.08 - 0.15
|
2219
|
|
93
Aluminum
Cu 6.3 - Mn 0.3 Ti-V-Zr
Melt range 1010 - 1190F
543 - 620C.
With the Cu above 4.5% hot cracking snsitivity decreased
|
2219-T81
|
|
Tensile
66 ksi
Yield 51 ksi
|
2219-O
|
|
Tensile
25 ksi
Yield 11 ksi
|
2219-31-351
|
|
Tensile
52 ksi
Yield 36 ksi
|
|
|
|
3XXX
Aluminum Series Aluminum - Manganese.
None
Heat Treatable Ultimate Tensile 16 to 41 ksi. Moderate strength, good corrosion
resistance, good for high temp use. Typically welded with 1xxx - 4xxx - 5xxx
|
3003
|
Germany
AlMnCu
UNI 7788
Italy P-AlMn1.2Cu
|
98.6 Alum - Cu
0.12 - Mn 1.2
Good Forming
Good Weldability
Used For Food Handling
Air conditioning or heat
exchangers.
Melt 1190F
|
3003-O
|
|
Tensile
16 ksi
Yield 6 ksi
|
3003-H14
|
|
Tensile
22 ksi
Yield 21 ksi
|
3003-H18
|
|
Tensile
29 ksi
Yield 27 ksi
|
3004
|
Germany
AlMn1Mg1
Italy PAlMn1.2Mg
|
97.8
Aluminum
Mn 1.2 - Mg 1
Melt Range 1165 - 1205F
630 - 650C
|
3004-O
|
|
Tensile
26 ksi
Yield 10 ksi
|
3004
- H34
|
|
Tensile
35 ksi
Yield 29 ksi
|
Weld
Note: POTENTIAL FOR EXCESS POROSITY ON COMPONENTS > 6 mm CONSIDER 60 HELIUM
40 ARGON
|
4XXX
Aluminum Series Aluminum - Silicon,
Heat Treatable and None Heat Treatable. Ultimate tensile strength 25 - 55
ksi. Silicon reduces lower melting temp, improves fluidity, often used for weld
electrodes. If the 4xxx contains magnesium or copper instead of silicon these
alloy are usually heat treatable and used when the welds will be subject to post
weld heat treat.
|
4032
|
|
85%
Aluminum
Si 12.2 - Cu 0.9
Mg 1.0 Ni 0.9
|
4032-T6
|
UNS
A994032
|
Tensile
55 ksi 380 MPa
Yield 46 ksi 315 MPa
|
|
|
|
5XXX
Aluminum Aluminum - Magnesium range 0.2 to 6.2%.
None
Heat Treatable. Ultimate tensile strength 18-51 ksi. These readily weldable alloys
have the highest strength of the none heat treatable alum alloys.
|
5005
|
Italy
PAlMg0.8
UNI 5764 - 66
|
99.2
Aluminum - Mg 0.8
Melt 1170F
Similar to 3003
|
5005-H16
|
|
Tensile
26 ksi
Yield 25 ksi
|
5005-O
|
|
Tensile
18 ksi
Yield 6 ksi
|
5050
|
|
98.6
Aluminum - Mg 1.4
Used for Appliance Trim,
Auto oil and gas lines
Melt Temp 1155 - 1205F
620 - 650C
|
5050-H34
|
|
Tensile
28 ksi
Yield 24 ksi
|
5050-O
|
|
Tensile
21 ksi
Yield 8 ksi
|
5052
|
Germany
AlMg2.5
Italy P AlMg2.5
A low strength alum alloy
|
97.2
Aluminum - Mg 2.5-Cr 0.25
Melt Range 1125 - 1200F
605 - 650C
Air Conditioners,
Heat Exchangers, Aircraft Fuel Lines, Fuel Tanks Street Lights, Appliances
|
5052-O
|
|
Tensile
28 ksi
Yield 13 ksi
|
5052
- H34
|
|
Tensile
38 ksi
Yield 31 ksi
|
5056
|
UNS
A95056
Germany AlMg5
Italy P-AlMg5
UNI 3576
|
95.5
Aluminum - Mg 5
Mn 0.12 - Cr 0.12
Wire products, Screens
|
5056 - H18
|
|
Tensile
28 ksi
Yield 13 ksi
|
5056
-O
|
|
Tensile
42 ksi
Yield 22 ksi
|
5083- 5 Mg is the highest strength non-heat-treatable
alloy in commercial use. 5083 provides good formability and weldability. 5083
has excellent tensile strength in the weld zone as a result of its as-rolled properties. 5083 is
used for ships hulls and the construction of tactical military vehicles. 5083 is also used in highly stressed welded assemblies, cryogenic vessels, dump
truck boxes and storage tanks.5083 has excellent resistance to corrosion.
|
5086
|
UNS
A95086
Germany AlMg4Mn
Italy P AlMg4.4
UNI 5452-64
|
95.4 Aluminum - Mg 4.0
Mn 0.4 - Cr 0.15
Melt 1085F. Used for
medium
strength applications, marine tanks, trucks. This alloy has good weldability and
is more formable than alloy 5083. As this alloy is resistant to stress corrosion
cracking and exfoliation, it also has wide application in the marine industry.
Corrosion resistance is excellent.
|
5086-O
|
|
Tensile
38 ksi
Yield 17 ksi
|
5086
- H32-
116 0 117
|
|
Tensile
42 ksi
Yield 30 ksi
|
5154
|
Germany
AlMg3.5
|
96.2
Aluminum Mg 3.5-Cr 0.25
Melt 1100
Tanks, trailers, trucks, pressure vessels
|
5154-O
|
|
Tensile
35 ksi
Yield 17 ksi
|
5154-H36
|
|
Tensile
45 ksi
Yield 36 ksi
|
5454
|
Germany
AlMg2.7Mn
Italy P-AlMg2.7Mn
High strength alum alloy with elevated temp applications
|
96.3
Aluminum Mg 2.7
Mn 0.8 Cr 0.12
Car wheels
Suitable for temperature
applications due to limit on Mg
|
5454-O
|
|
Tensile
36 ksi
Yield 17 ksi
|
5454-H36
|
|
Tensile
49 ksi
Yield 40 ksi
Melt Range 1115F - 1195F
600 - 650C
|
5456
|
UNS
A95456
|
93.9 Aluminum Mn 0.8
Cr 0.12 - Mg 5.1
Medium strength truck, structural
and marine.
Melt 1055F
|
5456
- O
|
|
Tensile
45 ksi
Yield 23 ksi
|
5456-H321-116
|
|
Tensile
51 ksi
Yield 27 ksi
|
5457
|
|
98.7 Aluminum
Mg 0.3 Mn 0.3
Melt range 1165- 1210F
630 - 655 C
|
5457-O
|
|
Tensile
19 ksi
Yield 6 ksi
|
5457
-H25
|
|
Tensile
19 ksi
Yield 7 ksi
|
5457-H28
|
|
Tensile
30 ksi
Yield 27 ksi
|
Metric
Conversion of Filler Strength. ksi x 6.894 = MPa
Aluminum
Alloy |
Designation |
Alloy Content / Description |
5652
|
|
97.2
Mg 2.5 - Cr 0.25
Melt range 1125 1200F
605 - 650C
|
5652 - O
|
|
Tensile
28 ksi
Yield 13 ksi
|
5652-H32
|
|
Tensile
33 ksi
Yield 28 ksi
|
5652-
H34
|
|
Tensile
38 ksi
Yield 31 ksi
|
5657
|
|
99.2
Aluminum Mg 0.8
Melt 1175F
|
5657-
H-28-38
|
|
Tensile
28 ksi
Yield 24 ksi
|
5657-
H25
|
|
Tensile
23 ksi
Yield 20 ksi
|
|
|
|
6XXX Aluminum Series Aluminum Magnesium Silicon,
(magnesium
silicides for heat treatment).
Ultimate
tensile 18 - 58 ksi. Fabtication, Extrusions. These alloys are solidification
crack sensitive, dont weld without filler metal. Typically welded with 4xxx
and 5xxx
|
6005
|
Germany
AlMgSi0.7
|
98.7
Aluminum Si 0.8 Mg 0.5
|
6005
- T1
|
|
Tensile
25 ksi
Yield 15 ksi
|
6005
- T5
|
|
Tensile
38 ksi
Yield 35 ksi
|
6351
|
|
97.8
Aluminum Si 1.0
Mn 0.6 Mg 0.6
|
6351 - T4
|
|
Tensile
36 ksi
Yield 22 ksi
|
6351
- T6
|
|
Tensile
45 ksi
Yield 41 ksi
|
6061
|
Germany
AlMgSiCu
UNI 6170-68
Italy P - AlMg1SiCu
|
98.5
Aluminum Si 0.7
Mg 0.8
6061 is a heat-treatable grade widely used
in light to medium strength structural applications. such as aircraft, marine,
furniture,
air conditioning and heat exchanger components.These alloys have
good corrosion resistance and weldability and possesses good formability in the
0 to T4 tempers.
6061 loses appreciable strength when welded and it
is replaced by the 5000 series alloys where afterweld strength is a prime consideration.
|
6XXX
IS OFTEN MANUFACTURED AS EXTRUDED COMPONENTS
|
6061-O
|
|
Tensile
18 ksi
Yield 8 ksi
|
6061-T6-651
|
|
Tensile
45 ksi
Yield 40 ksi
|
6061-T4-451
|
UNS
A96061
|
Tensile
35 ksi
Yield 21 ksi
|
6063
|
|
98.9
Aluminum Si 0.4 Mg 0.7
Tube, pipe, hardware
|
6063-O
|
|
Tensile
13 ksi
Yield 7 ksi
|
6063-T6
|
|
Tensile
35 ksi
Yield 31 ksi
|
6066
|
|
95.7
Aluminum Si1.4
Cu 1 - Mn0.8 Mg 1.1
|
6066-O
|
|
Tensile
22 ksi
Yield 12 ksi
|
6066-T4-451
|
|
Tensile
52 ksi
Yield 30 ksi
|
6070
|
|
96.8
Aluminum Si 1.4
Cu 0.28 Mn 0.7 Mg 0.8
|
6070-O
|
|
Tensile
21 ksi
Yield 10 ksi
|
6070-T4
|
|
Tensile
46 ksi
Yield 20 ksi
|
6151
|
|
98.2
Aluminum Si 0.9
Mg0.6 - Cr 0.25
Forgings auto parts
|
6151-T6
|
|
Tensile
32 ksi
Yield 28 ksi
|
6205
|
|
98.4 Aluminum
Si 0.8
Mn 0.1Mg 0.5 - Cr 0.1
Zr 0.1
|
6205-T1
|
|
Tensile
38 ksi
Yield 20 ksi
|
6205-T5
|
|
Tensile
45 ksi
Yield 42 ksi
|
6262
|
|
96.8
Aluminum Si 0.6 Cu 0.28. Mg 1- Cr 0.09 - Bi 0.6 - Pb 0.6
|
6262 - T9
|
|
Tensile
58 ksi
Yield 55 ksi
|
6351
|
|
97.8
Aluminum Si 1.0
Mn Mg 0.6
|
6351-T4
|
|
Tensile
36 ksi
Yield 22 ksi
|
6463
|
|
98.9 Aluminum
Si 0.4
Mg 0.7
|
6463-T1
|
|
Tensile
22 ksi
Yield 13 ksi
|
7XXX
Aluminum Aluminum Zinc. Heat Treatable.
Ultimate tensile strength 32 - 88 ksi.
Provide the highest strength aluminum alloys aircraft, auto, sports equipment.
Some weldable some unweldable. Often welded with 5xxx alloys.
|
7005
|
Al
- Zn - Mg alloys
|
93.5
Aluminum Mn 0.45- Mg1.4 Cr 0.13- Zn 4.5 - Ti 0.04- Zr0.14.
Resists hot
cracking better than
Al - Zn - Mg - Cu alloys such as 7075. Usually welded
with 5356 enough magnesium to prevent cracking. Avoid 4043 as the Si can make
the welds brittle.
|
7005-O
|
|
Tensile
28 ksi
Yield 12 ksi
|
7005-T53
|
|
Tensile
57 ksi
Yield 50 ksi
|
7075
|
Germany
AlZnMgCu1.5
Italy P - AlZn5.8MgCu
UNI 3735
|
90
Aluminum Cu 1.6 Mg 2.5 Cr 0.23 Zn 5.6
High sttrength Aircraft and structural
Melt 890 - 1175F
Unweldable, if welded stress corrosion cracks can occur,
(delayed cracking potential)
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7075-O
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Tensile
38 ksi
Yield 15 ksi
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7075-T6
T651
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Tensile
83 ksi
Yield 73 ksi
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7178
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welding
not recommended on this wrought alloy
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7475
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90.3
Aluminum Si 1.5 Mg 2.3 Cr 0.22 Zn 5.7
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7475-T61
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Tensile
76 ksi
Yield 67 ksi
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Warning:
To avoid cracks. Mixing alloys as typically occurs in welding dissimilar aluminum
alloys can increase the crack sensitivity. When selecting the aluminum filler
metal, examine the base alloy and filler alloy combination and avoid a final mix
of alloys high in both Mg and Cu content.
ALUMINUM
5xxx SERIES AND STRESS CORROSION (SS) CRACKING:
Question:
Ed what is stress corrosion cracking and how does it effect the 5xxx series aluminum
grades?
Answer: Stress corrosion cracking and part failure can occur from
an accelerated form of corrosion material in an application subject to tensile
stresses. The alum alloys subject to this form of corrosion are
2xxx series.
5xxxx
series that contain more than 3% magnesium.
7xxx series.
The 5xxx series
of alum has a magnesium content of 1 to 5%. The common 5 xxx series alloys with
> 3% magnesium which have been work hardened, can be sensitive to grain boundary
precipitation in select locations. The precipitation typically can occur if the
application is held at prolonged periods at moderate temperatures typically between
150 and 350F. In this temp range precipitate can form that are anodic to the alum
magnesium matrix leading to the corrosion issues. At temperatures above the 350F,
the grain boundary changes shape and reduces the potential for the formation of
SCC. The bottom line, the 5xxx alloys with > 3% magnesium should not be used
for elevated temperature applications.
It's important to note that there
are specific 5xxxx alloys designed specifically for elevated temp applications.
Alloys such as 5454 welded with 5554 have 2 to 3% magnesium making the suited
to elevated temp applications.
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