Summary for astm f2111 iga testing Discussion
IGA/EGP testing to ASTM F2111 is the focus of this question about how to run and interpret intergranular attack testing on 2024-T851 aluminum. The poster says the standard seems contradictory: it calls for mounting the specimen in a round metallographic mount, yet also says to examine the surface covered by the mount. The poster is also unsure how to measure pit depth when a microscope image appears only 2D. No technical answer is provided in the excerpt. The only response shown is a site note from the forum, reminding readers that the space is for camaraderie and sharing rather than free consultancy, and that some readers do not engage with anonymous posters. A partial, cut-off mention of a “3D Microscope on Amazon or” appears, but no usable guidance is included in the source excerpt.
IGA = Inter Granular Attack
EGP = End Grain Pitting
Q. Hi,
I have been trying to perform ASTM F2111 intergranular attack testing on 2024T851 aluminium. I am a bit confused as to how to interpret the specification as it asks me to mount the specimen in a round metallographic mount, but then asks me to examine the surface that has been covered by the mount.
Additionally, the spec wants me to look at the width and depth of the pits, but when I place it under the microscope I get a 2D image. I can measure length and width but depth is not possible.
If anyone can help I would appreciate it as I am at my wit’s end.
Kind Regards,
Gavin Darwen [fictitious]
– Blackburn Lancashire
September 13, 2023
This is a meeting place for camaraderie & sharing, not a free consultancy. So some readers don’t engage with anonymous posters.
A. A classical way of measuring depth on an optical microscope is to use focus: focus on the top surface, and then on the base of the pit, and use the difference in focal height to work out the depth.
This requires only a calibrated fine-focus knob with some graduations. World’s most accurate method? No, but for many cases it is plenty sufficient.
There are also these days plenty of 3-D measuring microscopes (optical or laser based). These will create a 3-D surface map and let you take measurements from it (2D/3D). More pricey but a reasonable investment if you’re going to be doing a lot of this sort of work.
Jenna Tong
– Melbourne, Australia