Nano- and micro-indentation studies on lithium borate–barium bismuth niobate glasses

详细信息    查看全文

• 作者：Kaushik Das ; C. Karthik ; K.B.R. Varma ; U. Ramamurty
• 关键词：Crystallization ; Glass– ; ceramics ; Mechanical properties ; Fracture ; Hardness ; Indentation ; Microindentation ; Borates
• 刊名：Journal of Non-Crystalline Solids
• 出版年：2008
• 出版时间：15 August 2008
• 年：2008
• 卷：354
• 期：32
• 页码：3793-3798
• 全文大小：1223 K

文摘

The structure and mechanical properties of multifunctional lithium tetra-borate based glasses and glass–ceramics of the system (100 − x) Li₂B₄O₇₋x(BaO–Bi₂O₃–Nb₂O₅) with x = 10, 20 and 30 in molar ratio, have been characterized. Nano- and micro-indentation techniques were employed to evaluate the elastic modulus, hardness and toughness of the as-cast and annealed glasses. These were complemented with detailed structural investigations using X-ray diffraction, microscopy (optical, scanning electron and high resolution transmission electron microscopies) and nuclear magnetic resonance spectroscopy. These investigations reveal a smooth variation of the mechanical properties with composition except for the composition corresponding to x = 20. This deviation has been attributed to subtle changes in the glass-structure due to amorphous phase-separation and heat-treatment-assisted nano-crystallization.