| Laser, as a heater, had been used to preparate nano- materials in the past years, because of its instant nonequilibrium output of energy and speedy heat up the materials which were irradiated by laser beam. When the laser irradiated on the nano-materials, the energy of laser took on gradient distribution in the three dimensional space of laser irradiation so that materials of gradient distributed structure were got.In-situ growth of SiC nano-whiskers by direct laser irradiation on SiC nano-particles was investigated in this paper. Process parameters of laser and steady growth conditions of SiC nano-whiskers by laser irradiation were researched. The main work accomplished and conclusions got were presented as follows:1. Laser energy model of gradient distribution was established after laser beam was simplified to gauss beam. The influence of laser parameters including laser spot diameter, laser power and scanning speed on SiC nano-particles was analyzed with reference to the experiment result.2. Laser spot diameter was calculated in theory. With the calculationg formula, laser spot diameter could be determined if the height of laser head was got.3. Temperature field of the irradiation layer was established and analyzed, which could be used to research the temperature of whisker growth.4. The experiment of laser irradiation was made out with the method that the laser and surface irradiated are upright. The microstructures of the sample got by laser irradiation were studied in detail with scanning electron microscopy.5. Helical, reticular and claviform whiskers were got through in-situ growth on SiC nano-particles. Some of the whiskers queued in one order, some collected disorderly like spherality or floccule and some collected in one order like beard.6. Growth process of three kinds of whisker was researched. And the effect of laser parameters and three binders which was PVB, PVA and CMC on the growth of whiskers was analyzed.
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