Generally speaking, under a microscope, the flake diamond micro powder has low strength, strong block cutting force and good quality; coarse diamond micro powder is easier to judge. A good diamond micro powder is observed under a microscope and has good transparency and its core is transparent. Surrounded by black outlines, bad diamond micro powder is all black.
Ultra-fine diamond micro powder refers to diamond micro powder with a particle size of less than 1.5 μm. It needs to be immersed in cedar oil for observation, magnified by 1600 times. Conventional glycerin sample preparation is difficult to observe and easy to agglomerate; the quality of ultra-fine diamond powder can be distinguished from imaging. But it requires more practice and observation. Another advanced method is to use a differential thermal analysis instrument to judge the initial oxidation temperature of the diamond powder. Because the instrument is relatively expensive, it is not suitable for promotion in industrial production.
In order to solve this problem, a new type of dispersant can be used to solve the problem of dispersion of ultrafine diamond powder, and the microscope can be immersed in oil to achieve clear imaging. Scanning electron microscope observation of ultrafine diamond powder and nano-diamond powder is very clear, and the size measurement is accurate. However, the surface of the diamond powder particles needs to be sprayed with a metal film to observe, so that the structure and crystal appearance of the diamond powder are not clear, and it is difficult to judge the quality level of diamond micro powder. From this perspective, traditional biological microscope observation still has great advantages.
In addition, through the innovation of sample preparation of diamond micropowder crystals, color images are taken, and the quality of diamond micropowder is judged according to the color of the graph. In order to avoid the displacement of the diamond micro powder in the dispersant, and to take a clear image, a new sample preparation method is used to fix the diamond micro powder, and the real diamond micro powder image is taken under the biological microscope.