×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Wrinkled/textured metal surface after test.
3

Wrinkled/textured metal surface after test.

Wrinkled/textured metal surface after test.

(OP)
Hello all,

Upon testing some electro-polished metal test specimens, axially and in tension, the smooth electro-polished surface changes dramatically to a wrinkled or textured surface, why?

I can't seem to find anything that explains this effect on the internet, including academic papers and these forums. It is likely that I don't know the correct terminology. My guess at this point is that the change is due to the grains deforming/twisting/slipping and thus disrupting the originally smooth surface. References to papers or other resources to help explain this effect is most welcome.

The parts are small, roughly 0.2 mm square cross section and are cut from tubing with a 3 mm outer diameter. The material is 316 stainless steel with a grain size print call out of > or = to 8 per ASTM E112.

A picture is attached to illustrate. The tab (on the left) shows the original surface while the small area (on the right) shows the deformed surface.

Thank you for any help you can provide.
acspain

RE: Wrinkled/textured metal surface after test.

2
It is well known that the free surfaces of metals become rougher during plastic
deformation. Many studies show the influence of strain, grain size, stress
mode and texture on surface roughness characteristics.
The surface roughness is found to increase linearly with
strain and depends linearly on grain size The
roughness increment is not very dependant onthe stress state
whereas texture has been found to have a great influence on
the roughness.7–9 Most of these studies are aimed at
A number of studies have shown that
plastic deformation roughens a surface by introducing
slip bands within grains and strain incompatibilities
between grains.

O. Wouters, W. P. Vellinga, R. van Tijum and J. T. M. de Hosson:
Acta Mater., 2005, 53, 4043–4050.
M. R. Stoudt and R. E. Ricker: Metall. Trans. A, 2002, 33A, 2883–
2889.
Y. Z. Dai and F. P. Chiang: J. Eng. Mater. Technol. Trans. ASME,
1992, 114, 432–438.
M. Baydogan, M. A. Akoy, E. S. Kayali and H. Cimenoglu: ISIJ
Int., 2003, 43, (11), 1795–1798.
R. Mahmudi and M. Mehdizadeh: J. Mater. Process. Technol.,
1998, 80–81, 707–712.
Y. Z. Dai and F. P. Chiang: Mech. Mater., 1992, 13, 55–57.
O. Wouters, W. P. Vellinga, R. van Tijum and J. T. M. de Hosson:
Acta Mater., 2006, 54, 2813–2821.
Y. S. Choi, H. R. Piehler and A. D. Rollett: Metall. Trans. A, 2004,
35A, 513–524.
R. Becker: Acta Mater., 1998, 46, (4), 1385–1401.
I. Shimizu, T. Okuda, T. Abe and H. Tani: JSME Int. J. Ser. A,
2001, 44A, (4), 499–506.

RE: Wrinkled/textured metal surface after test.

Luder's lines
http://www.advantagefabricatedmetals.com/metalform...
from the non uniform straining of the surface.

Or Orange peal, that has to do with dislocation slip in coarse grained structures.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources