New analysis of ancient metallurgical slag heaps at the archaeological site of Ujjayini (modern Ujjain) has uncovered evidence of highly specialized nickel-bronze production dating back to the 6th century BCE. The study reveals that ancient smiths employed a multi-stage smelting process to achieve a specific nickel content that improved the hardness and corrosion resistance of the tools produced.
This discovery pushes back the timeline for specialized non-ferrous alloying in Central India, predating the Mauryan Empire's industrial expansion. The researchers believe these high-performance alloys were used primarily for specialized medical and surgical instruments, as evidenced by the refined chemical purity of the samples found near ancient forge sites.