Octo-Alloy, also called Ashtadhatu, is a traditional alloy to produce religious idols, ornaments and sculptures in indian subcontinent. My question regarding the alloy is
- According to wikipedia,( https://en.wikipedia.org/wiki/ Ashtadhatu ), the alloy consists of gold, silver, copper, lead, zinc, tin, iron and antimony or mercury . Does this alloy consisting of so many dissimilar metals undergo phase separation during casting? Are there any research papers available about microstructure of this alloy, or about phase separation prevention of this alloy?
- Again, some ornaments, especially bangles made of this alloy are made in forms of two interwinning wires of different color. Which metals are incorporated into which wire?
- Where can I get credible Archeometallurgical and contemporary methods of casting (temperature, composition, time)and metalworking ( embossing, scribing) of this alloy? Was this work of a jeweler, a sculptor or a metallurgist?
- Is there any possibility that the alloy is a high-entropy alloy? Have there been any research on molecular dynamics simulation of high entropy alloy of these particular alloying elements? I have not found any in interatomic potential repository
- Had there been any research on MEDICAL (NOT ASTROLOGICAL) benefit of using octo-alloy( more specifically its self-disinfecting capability and heavy metal poisoning hazard)?
I suspect that the term octo-metal comes from the number of metals [8 (octo)] that you listed. The alloy bears a similarity to an alloy called Ashbury metal that is a form of pewter that was used for cutlery. It is 14% Sb, 2% Cu, 1% Zn, 3% Ni and 80 % Sn. Perhaps an artisan or craftsman started with a form of this alloy and added others to get a desired look or properties. Unfortunately, I do not know of any resource that would answer your questions. I suspect it is difficult to find samples to study because of its rarity and religious nature.
You have raised a very attractive querry.You may get clarification and understanding on some points raised in your querry by approaching prof b s murty, director iit hyderabad. He has a book on high entropy alloys and is an ex-student of eminent metallurgist&material scientist Prof.S Ranganathan of iisc bangalore.
Definitely not a "High Entropy Alloy" as the term is misleading. At low temperatures the enthalpy term dominantes the alloy behaviour and the entropy term is negligible. Now the preferred term is Multi Principal Component Alloy. Maybe this alloy is one of those (you don't give a composition so some elements may be minor additions) but certainly it will phase separate as do most MPCA's, hence they cannot be called high entropy alloys. If there is any significant lead and mercury in it I would stay well away from it from a health perspective. Alloys of transition metals and Group III-V tend to form compounds so I would expect significant compound formation on solidification for this alloy.
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