Solubility and Dissolution Mechanism of Nitrogen and Carbon in Oxide Melts

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 11555194
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Metal making engineering
• Research Institution: Kyushu University
• Principal Investigator: NAKASHIMA Kunihiko Kyushu University, Graduate School of Engineering, Associate Professor, 工学研究院, 助教授 (10207764)
• Co-Investigator(Kenkyū-buntansha): MORI Katsumi Kyushu University, Graduate School of Engineering, Professor, 工学研究院, 教授 (80037754)
• Project Period (FY): 1999 – 2001
• Keywords: Al_2O_3-Y_2O_3-SiO_2 melts / Y-Al-Si-O-N glass melts / nitrogen solubility / viscosity / oxynitride glass / Vicker's hardness / ビッカース硬度

Research Abstract

The viscosity and the solubility of nitrogen using silicon nitride (Si_3N_4) as a source of nitrogen for Al_2O_3-Y_2O_3-SiO_2 melts have been systematically examined. The effects of nitrogen content on viscosity for Y-Al-Si-O-N melts have been also examined. Microhardness of oxide and oxynitride glasses in these systems have been measured.
The viscosities of Al_2O_3-Y_2O_3-SiO_2 melts decreased, and the solubility of nitrogen into the oxide melts increased with increasing Y_2O_3 content. These results could be explained that yttrium ion is a network modifier and the amount of non-bridgeing oxygen increases in the melts.
The viscosities of Y-Al-Si-O-N glass melts and Vicker's hardnes of oxynitride glasses remarkably increased with increasing nitrogen content. These results implied that the trivalent nitrogen substitutes for bivalent oxygen to produce a more tightly linked network and most of the nitrogen is linked to three silocons.