Tuesday, July 24, 2018

1181. Ancient Indian Metallurgy.

We have an industry in Bengaluru catering to Electrical Motor and Transformer industries. Our main raw material is Electrical Steel which is special steel alloy having magnetic properties. This iron alloy becomes special with the addition of Silicon which has got the properties to make the alloy produce specific magnetic properties. Silicon is an abundant element on Earth next only to oxygen. Though Silicon is not found free in nature it occurs chiefly as silicon dioxide and as silicates. Handful of sand from the beach has by mass 47% of Silicon in the form of Silica. The variation in Silicon content in the metallurgy of this special steel alloy enables us to get better electrical parameters when used in the appliances like motors and transformers. 

Initially when we were new to this field we found it difficult to understand about this steel. Our practical knowledge was limited due to the overloaded theoretical knowledge got from books and lecture on this alloy. We had read about these metals in our Material Science class when in college but had never seen one. It was here I understood that theory was different from practical; it was tough to get the appropriate steel from the traders to suit to our client’s requirement. At one instance, we had a client who was a vendor to the Electronics and Radar Development Establishment of the Defence Research & Development Organization. He required a particular core section for a transformer and we assured him of getting him the core section. It was an R & D project for him too and I would take the samples to his unit in the morning and by evening he would call me and say that the core has not met the required electrical parameters. We ended up giving 19 samples. It was very difficult for us to get the perfect electrical steel grade to match their requirement. Finally we did pin point the required raw material to supply to the client who made transformers for DRDO. That is when my interest towards material science got a push, internet and various books on metallurgy caught my attention. From ferrous to non ferrous my interest grew. 

Metallurgy is not a new topic for us as our ancients were experts in it. My post yesterday mentioned about iron cast of Bhimasena done by Sri Krishna, one of my readers was surprised and wanted to know if the art of casting was known during Mahabharata times. 

“Lohakarma Shastra” (Metallurgy) was done by the process of Secana (Pouring of Metal). In fact metals were mentioned in Vedas much before Mahabharata and Ramayana. Rig Veda mentions about Hiranya (Gold) and Ayas (Iron), (Note: we call magnet “Ayas-Kanta”', Iron-Lover as magnet attracts iron). Atharva Veda talks about Rajata (Silver), Trapu (Tin) and Sisa (Lead). There are many literature from Siddhas who were proficient in handling Avityaja (Mercury). They have a secret formula to solidify mercury which has medicinal benefits.

In our ancient texts like Mahabharata and Agni Puranas there is a reference of a word “Taila Dhauta” that is done to the arrow heads. Taila in Sanskrit is oil, Dhuta is wash. In today’s world we make the iron alloy brittle by a treatment. The process involves heating the iron alloy at high temperature and immediately immersed the white hot alloy in oil at room temperature; this process is called “hardening.” The iron alloy hardens by losing its resilience quality making it brittle. Arrow heads and sword edges need to be brittle. 

We had artisans who could make mirrors out of metal. Even though we do not have the evidence to prove our hold on metallurgy, we can know that our ancients were well-versed in handling metals in the past.

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