Structural, thermal, and chemical properties of boron oxide-doped molybdate glass for use as a lead-free low-temperature sealing material

Abstract

For lead-free low-melting sealing materials, the boron oxide alkali molybdate glass system was investigated with different boron oxide contents between 0 and 8 mol%. The glasses were characterized using differential scanning calorimetry, and infrared spectroscopy, and by their dissolution rates and densities. As the boron oxide contents increase, the glasses maintain their low temperature properties (Tg under 175°C), and new network formers of [BO3] triangular units and [BO4] tetrahedral units appear. The glasses possess MoO4, MoO6, BO3 and BO4 groups as basic structural units, and existing weak Mo-O-Mo bridge bonds convert into strong Mo-O-B bridge bonds. As a result, chemical durability is improved.