Occurrence of airborne silicon carbide fibers during industrial production of silicon carbide.
分析了碳化硅生产车间的空气粉尘，发现其中含有α碳化硅纤维，80%的纤维直径小于0.5微米、长度大于5微米，三个工厂的纤维浓度均低于1根/立方厘米。
Airborne dust from the production of silicon carbide has been analyzed for particle morphology and composition. Fibers of alpha silicon carbide were identified by scanning electron microscopy (SEM) combined with energy dispersive X-ray spectrometry (EDS) and transmission electron microscopy (TEM) with selected area electron diffraction techniques (SAED). Micrographs taken at high magnification revealed several stacking periods along the fiber axis, and one or more of the polytypes 2H, 4H, or 6H could be distinguished. Preliminary investigations applying SEM showed that 80% of the fibers had diameters of less than 0.5 micron and a length greater than 5 micron. Fiber concentrations were examined by the counting of stationary and personal samples in an optical phase contrast microscope. The fiber levels in the three plants investigated were low and less than 1 fiber/cc of air (10(6) fibers/m3). Dust samples from the handling of raw material, including recycled material, contained up to 5 fibers/cc (5 X 10(6) fibers/m3).