The influences of cations on the properties of Y-Mg-Si-Al-O-N glasses

Two series (A and B series) of oxynitride glasses were prepared by melting batches at 1580 degrees C for 3 h under local CO reducing atmosphere in a Si-Mo-heated resistance furnace. Nominal compositions of A and B series glasses in equivalent percent (eq.%) are (28-x)Y:xMg:48Si:24Al:830:17N and (28-x)Y:xMg:56Si:16Al:830:17N (x = 0, 7, 14, 21), respectively. The influences of Mg/Y and Al/Si ratios on the properties such as glass transition temperature (T-g), crystallization temperature (T-c), knoop hardness (H), three-point bending strength (sigma) and chemical durability in 20%HF were investigated. At the same time, the relationship between these properties and the structures of the glasses were discussed. At constant ratio Si/Al/O/N, T-g decreases nonlinearly but glass leaching ratio increases linearly with increasing Mg/Y ratio. However, H and sigma increase first and then decrease as the Mg/Y ratio increases. When the Y/Mg/O/N ratio is constant, T-g decreases slightly but H and a increase slightly as the Al/Si ratio increases. (C) 2008 Elsevier B.V. All rights reserved.