Synthesis and studies on microhardness of alkali zinc borate glasses

Abstract

The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi2O+yNa2O+80B2O3 (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li2O and Na2O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO4/2)- into (BO3/2)-. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category. � 2014 AIP Publishing LLC.