Formation of Mg2Si inclusions in in situ SiC doped MgB2 wires made from variable concentration of large micrometer-size Mg powder by continuous method

Abstract

In the continuously manufactured SiC doped in situ MgB2 wire made from 100-150 μm size Mg powder and nanosized Boron, there is formation of the Mg2Si micro-inclusions in the body of the wire in addition to elongated Mg2Si inclusions three orders of magnitude larger by volume, localized in position of original elongated Mg ribbons. Provision of excess of Mg powder up to 15% was conducted in aim to satisfy full use of the B particles and reduction of large Mg2Si inclusions. Microstructural reflectivity and EDAX SEM analysis of phase formation in the wire prove that complex solid-liquid reactions in Mg-Si-C-B systems take place during the first few minutes of reactive diffusion processes. Result of the Jc(B, T) characteristic is provided to discuss the influence of SiC doping on conductor characteristics in magnetic field. Analysis of the influence of Mg2Si inclusions on artificial pinning mechanisms is discussed in conjunction with possible improvements in product, process and performance.