Home /
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989


IGA/EGP testing to ASTM F2111

IGA = Inter Granular Attack
EGP = End Grain Pitting

Q. Hi,
I have been trying to perform ASTM F2111 [affil link] 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
- Blackburn Lancashire
September 13, 2023

Ed. note: Since 1989 we've strived to build a legacy of aloha & camaraderie incompatible with anonymity; everyone is welcome to read anonymously, but is asked to use their real name & town when posting :-)

3D Microscope

(Affil. Link - as an Amazon Associate, finishing.com earns from qualifying purchases)

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 3D measuring microscopes (optical or laser based). These will create a 3D 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
September 18, 2023

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA