In in situ sintering, B and Mg reacts to form MgB2 phase, lower dense bulk material is generally obtained due to the volatility of magnesium. In order to improve mass density of the bulk and improve inter-connectivity between MgB2 grains, we have developed Infiltration and Growth (IG) technique.  In this IG process, Boron precursor pellets of varying characteristics are infiltrated with liquid Mg to obtain dense bulk MgB₂. These IG samples typically contained MgB₂ with minor quantities of residual Mg. To aid inflitration and eliminate continuous Mg channels, we have adapted reactive wetting concept in which thermodynamically least stable AlB₂ was introduced to B precursor prior to infilatration of liquid Mg. This approach leads to a more uniform infiltration process, with reduced residual Mg, thereby enabling fabrication of near-net shaped high performance of MgB₂ bulk superconductors. Such samples showed homogeneous critical current density, J_c, and higher trapped magnetic flux, suggesting high degree of uniformity in MgB₂ phase formation.

Keywords: MgB2 bulk, Trapped magnetic fields