Usually, it is a preparation method of ultrafine powder that uses gas or materials to prepare gas, causes physical or chemical reaction in the gas state, and condenses and grows up to form particles in the cooling process. The gas phase reaction method methods of Chang can be divided into gas phase decomposition method, gas phase synthesis method and gas-solid reaction method. Non oxide ultrafine powder, such as metal carbide, nitride and boride, which are difficult to prepare by liquid phase method, can be prepared by controlling the gas phase method.
No classification at present.