Composites consisting of Mg and MgB2 phases were fabricated by liquid-metal infiltration following two routes. First, a preform of MgB2 powders was pressure infiltrated at 800 °C with liquid Mg, which was subsequently solidified. Second, a preform of B powders was pressure infiltrated with liquid Mg at 700 °C, resulting in partial, in situ formation of the MgB2 phase. Subsequent annealing at 95...