Physical and chemical properties of the heat resistant diamond compacts from diamond-magnesium carbonate system
Physical and chemical properties of the heat resistant diamond compacts from diamond-magnesium carbonate system
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DOI：
10.1016/0921-5093(96)10111-8
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发表时间：
1996-05
期刊：
影响因子：
6.4
通讯作者：
M. Akaishi;S. Yamaoka
中科院分区：
文献类型：
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作者：
M. Akaishi;S. Yamaoka
研究了粒度为20 ~ 30 μm的天然金刚石粉末与碳酸镁在7.7GPa、1800-2450 °C的高压高温下的烧结行为。使用碳酸镁作为烧结剂，在7.7GPa的条件下在高于2200 °C下合成具有均匀微观结构的良好烧结的金刚石，其具有67 GPa的努普硬度。通过将充分烧结的金刚石热盐酸处理15.5小时，未证实碳酸镁的显著挤出或溶解。真空中在900-1400 °C之间热处理30 min后，压坯内部和表面均未观察到石墨化或裂纹。高于1300 °C处理的压块的努普硬度降低至55 GPa，而低于1100 °C处理的压块的努普硬度不变。
The sintering behaviour of natural diamond powder with a grain size from 20 to 30 μm was investigated at high pressure and high temperatures of 7.7 GPa and 1800–2450 °C with magnesium carbonate. A well sintered diamond, with a homogeneous microstructure, was synthesized under conditions of 7.7 GPa at above 2200 °C using magnesium carbonate as a sintering agent, which had a knoop hardness of 67 GPa. By the hot hydrochloric acid treatment of the well sintered diamond for 15.5 h, a marked extrusion or dissolution of the magnesium carbonate was not confirmed. Neither graphitization nor crackings were observed in and on the compact after the heat treatment between 900–1400 °C for 30 min in the vacuum. Knoop hardness of the compact treated above 1300 °C decreased to 55 GPa while those treated below 1100 °C were unchanged.