Where theworld gathers for metal finishing
Q&As since 1989
-----
Fatigue strength and Hardness of EN 6060, T66 - F22
Q. I work for an automotive supplier.
We supply a latching base plateau made from extruded AL alloy, EN-AW-6060, T66, hardened to F22. We had a failure/breakage and are looking now for property data, specifically Brinell hardness range and fatigue strength and fatigue curves. If someone could get me that information or guide me to a website (subscription sites are fine) I would really appreciate it.
Thank you in advance
1st tier automotive - Rochester Hills, Michigan
2003
A. The original manufacturer of the aluminum should be able to give you some or all of that data. But any data is averages of the material that was tested. Extrusions may not vary as much as castings, but will vary wildly in strength, even when cut from the same extrusion. Has to do with the uniformity of the mix and the extrusion process itself. You may have to go to a stronger alloy.
James Watts- Navarre, Florida
2004
A. 6061 T6 is much stronger than 6060 aluminum which you may know but has a grey appearance compared to 6060 - of course there are so called aircraft aluminum parts difficult to extrude but very strong in the 7XXX series. Not sure if you are extruding a shape then milling the finished part then T6 temper or purchasing flat plates pre-tempered.
1. The verification of temper can be done with a variety of testing methods - the simple chart [at left] tells you what to expect.
A simple hand held machine that measures temper on flat stock is a Webster (for 6060 expect about a Webster 12 to 13 or Brinell 70 to 75) - the ranges are included in the chart for tensile, hardness using all the various scales and alloy family.
2. There are several aspects to strength and hardness...if the plate was purchased - you should get a certificate to define the actual temper and F22 (220 MPa is fair strength for 6060 alloy... EN AW 6060 Rm = 215 MPa - fair strength means that someone actually performed a tensile test on your fabricated sample as many things can go wrong such as wrong temper in the temper oven, poor homogenization and poor extrusion conditions with badly formed weld lines and so forth - yet fabricators go through their process and report without testing (hopefully you have actual data that makes this mute). However, there is 100% correlation to a good hardness reading and strength expected.
3. As you may know, the elongation for 6060T6 is fairly low at 6%- so if your latch is expected to bend a great deal - not possible.
4. A stronger alloy such as EN AW 6061 can give you more resistance to bending and higher loads up to a T6 F31 and elongation up to 12% and may be more capable in your application. Again the Webster is 15 to 17 and Brinell (10 mm ball 500 kg load) over 90 for 6061.
Hope this helps.
Minth Group - Farmington Hills, MI, USA
Q, A, or Comment on THIS thread -or- Start a NEW Thread