Grain Microstructure

1. Does the grain microstructure change if platinum is being remelted for so many times?
2. Do you think adding virgin material to the scrap will improve grain microstructure?
3. Based on your experience, after how many remelts you think we should start adding virgin material?

Hello There,

Wow, we are sure getting a lot of exotic metallurgical requests this year such as Zinc Wire Manufacturing, Zinc Wire Drawing Lubricants, Platinum-Iridium Drawing Issues, Molybdenum Wire Drawing and now Metallurgical Grain Structure Issues with Platinum.

I am not a metallurgical engineer and certainly not an expert in the metallurgy of platinum so I suggest you contact the following:

International Platinum Group Metals Association
Schiess-Staett-Strasse 30
80339 Munich, Germany

Telephone: (+49) (0)89 519967-70
Fax: (+49) (0)89 519967-19
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Website: www.ipa-news.com/en/

One of their core objectives is to generate and promote factual information on platinum so your questions should be right in line with their objective.Please let us know how you make out with the IPGMA. Thank you.

YanQing,

It depends on what you mean by improving the grain structure. Over succesive remelts of scrap the material will pick up impurities and get less pure so additions of virgin material would generally be required to maintain the desired purity of the material rather than improving the grain structure.

The amount of cold work and annealing will have the greatest effect on the grain structure although purtity will have some effect in that very pure material will recrystallise easier than dirtier material. So if a small refined grain structure is prefered it would be beneficial to not have a very high starting purity and just blend in virgin material to maintain the minimum purity required.

Mike