Breathe easy! No registration or passwords; no maddening pop-up or floating ads :-)

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


Aluminium Wire Rod Surface Problem

Q. I work in an Aluminium smelter in Eastern India. We have an aluminium hot rolling mill supplied by Properzi. In some of the coils, a hard & black layer is getting formed. The black layer is not on the full coil but in patches. This is creating difficulty in wire drawing process. The drawing dies are getting prematurely damaged due to this. The black layer is getting generated during storage. The problem is more common during the rainy season.

Manasa Mishra
- Nagar, Orissa, India

A. Have you tried to characterize the black coating as to organic or inorganic? Does it burn?, does it leave a residue upon ignition? What is its melting point? Have you charted the occurrence of the black coating along a time line for a year? with * for date the aluminum was poured, and # for date the coil was drawn.


or something like that. This might be helpful even if you can get a sample of the wire to a university for analysis.

tom & pooky   toms signature
Tom Pullizzi
Falls Township, Pennsylvania

A. It's due to oxidation, long exposure to moisture.
1) Check your machine after quenching: water should not get carried with rod.
2) Don't pack hot coil
3) Check your storage area

Rebel 55
Student - India
May 8, 2023

Ed. note: We've been building a legacy of aloha & camaraderie here that is incompatible with anonymity;
everyone is welcome to read anonymously, but is asked to only post with their real name :-)

(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, Pine Beach, New Jersey, USA