Studies on an Ancient Aircraft Material – Panchaloha

Abstract

This paper reports the preparation and characterization of Panchaloha, an ancient aircraft material, described in the ancient Sanskrit text Bharadwaja’s Vymanika Sastra (BVS). The alloy composition was deciphered as a leaded brass. Liquid metallurgy using coal fired blower fitted furnace was employed for preparation of the specimens and they were characterized for density, tensile properties, hardness, electrical conductivity and microstructure. The specimens were found to be golden yellow in colour and the percentage of lead in the alloy varied between 6 and 7 %. Experimental density was 6 % less than the theoretical density (8.88 g/cc). Ultimate Tensile Strength was 168.6 MPa and the specimens were found to be fairly ductile with 9.5 to 11 % elongation. The electrical conductivity was in the range of 25 to 33 % of pure copper even with the presence of high amount of lead in the alloy. Uniformly distributed microporosity was the main feature of the microstructure. Thus most of the properties of the alloy specimens were found to be in conformance with the descriptions in Bharadwaja’s Vymanika Sastra.