温度对铁基预合金粉腐蚀泡沫化人造金刚石微粉的影响

采用铁基预合金粉对粒径为40~50μm的人造金刚石微粉进行腐蚀泡沫化处理。研究了不同温度对金刚石微粉表面形貌、颗粒直径、比表面积和孔容积的影响,并对腐蚀图案的各向异性和泡沫化机理进行分析。结果表明:当金刚石和预合金粉质量比为1∶2时,800℃处理的金刚石表面出现明显的腐蚀坑。随着处理温度升高,金刚石泡沫化程度先增大后减小,当处理温度为1 000℃时,金刚石泡沫化效果最好;此时,金刚石的比表面积和孔容积最大,分别为7.322m2/g和0.012mL/g。在腐蚀泡沫化过程中,金刚石发生了石墨化。

Influence of Temperature on Etching and Foaming Behavior of Synthetic Diamond Powder by Iron-based Pre-alloyed Powders

Synthetic diamond powder with size of 40-50 μm was etched using iron-based pre-alloyed powder.Effect of temperature on the surface morphology, particle size, specific surface area and void ratio of the processed diamond was investigated.The anisotropy of etch pits and the foaming mechanism were also analyzed.Results showed that when the mass ratio of diamond to iron-based pre-alloyed powder was 1∶2, etch pits were formed on diamond surface at 800 ℃.With the increase of temperature, the foaming extent of diamond first increased, and then decreased, while the particle size of processed diamond decreased.At 1 000 ℃, the foaming effect was the optimum, and the diamond exhibited a loose and porous structure.At this time, the specific surface area and pore volume value reached the maximum, which were 7.322 m2/g and 0.012 mL/g, respectively.During the diamond foaming process, phase transformation from diamond to graphite occurred.