以碳纳米管为外加碳源爆轰合成聚晶金刚石

To study the phase transformation mechanism of carbon nanotubes during detonation, synthesis experiments were carried out using direct detonation method with carbon nanotubes as the additional carbon source. The detonation product was chemically purified. X-ray diffraction (XRD) was used to characterize the purified product, and it was found that the product consisted of diamond. The purified product was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and after in-depth analysis, it was found that the carbon nanotubes transformed into diamond through solid in situ phase change during the detonation process. Multiple cores were observed on a carbon nanotube to form crystals at the same time. When adjacent crystals came into contact, crystal boundaries were formed, limiting growth in specific directions to form polycrystals. Depending on the circumferential, radial and axial dimensions of the formed diamond crystals, as well as the number and position of the crystals in the formed polycrystals, polycrystalline diamond particles of different shapes such as tubes, flakes, and blocks were obtained.