METHODS FOR MANUFACTURING MAGNESIUM DIBORIDE (MGBâ‚‚) SUPERCONDUCTOR WIRE COVERED IN STAINLESS STEEL (SS) USING POWDER-IN-TUBE (PIT) TECHNIQUE THROUGH OPTIMIZATION OF CRITICAL TEMPERATURE (Tc) AND CRITICAL CURRENT DENSITY (Jc) AS WELL AS A STAGED COLD DRAWING PROCESS

Abstract

This invention discloses a method for manufacturing stainless steel (SS)-sheathed magnesium diboride (MgB₂) superconducting wires based on a powder-in-tube (PIT) technique adapted through a multistep cold drawing process to optimize the critical temperature (Tc) and critical current density (Jc). A mixture of magnesium (Mg) and boron (B₂) powders is introduced into a SS tube, followed by end-to-end compaction to prevent oxidation, and then progressively reduced in size to a final diameter of 3.0–3.5 mm. Sintering at 800°C and annealing to 1000°C results in a dominant MgB₂ phase with low porosity and high grain connectivity. This method results in a 3.5 mm diameter wire reaching a critical onset temperature of 39.44 K, and a 3.0 mm diameter wire having a critical current density of 10₂ A / cm² at a 1 Tesla field.This invention provides high-quality MgBâ‚‚ superconducting wire with superior mechanical strength and economical production process, suitable for cryogenic applications, lossless energy transmission, and industrial magnetic devices.