Molybdenum has been used for booster and primary electrodes in the glass melting industry since the 1960s, experience has shown that purity & metallurgical structure can have an effect on the life & performance of the electrode. Impurities & porosity in the molybdenum can cause adverse coloration & gas bubbles in the glass whilst impurities in the glass can cause erosion & corrosion of the electrodes. Fine grained material exhibits a greater resistance to corrosion but is prone to sagging, especially in the case of side & bottom entry electrodes. Ideally, the grains should be large & elongated along the electrode axis. Electron beam melted & forged electrodes are premium products that offer higher purity than conventional powder metallurgical material combined with a coarse elongated grain structure ensuring long life & stability in service.
