The invention relates to a method for preparing a corrosion-resistant and wear-resistant tantalum composite coating, which includes the following steps :(1) the vapor deposition reactor and all pipes are flushed and drained by inert gas; (2) Put the material to be deposited into the gas phase deposition reactor after treatment; (3) Vacuum pump is used to vacuum the vapor deposition reactor and heat the reactor at the same time; (4) The tantalum halide is heated to 50 250℃ in the evaporator, and the tantalum halide gas is carried into the reactor with carrier gas, and N2 and H2 are passed into the reactor at the same time, and the reaction takes 0.5 to 5 hours. (5) When N2 is stopped and H2 is continued, the reaction continues and tantalum coating is formed on the surface of the material. (6) Take out the sedimentary sample. The invention has the advantage of depositing dense tantalum coating on stainless steel and ceramic valves, bearings, pipe fittings and other commonly used industrial parts, which improves the corrosion resistance of the parts and significantly prolonging the service life of the parts.
Tantalum is a refractory metal with high melting point (2996°C, second only to W and rhenium Re), high high temperature strength, low thermal expansion coefficient, good electrical conductivity, weldability and high corrosion resistance (comparable to platinum at room temperature). Tantalum is deposited on valves, pipe fittings, heat exchangers, chemical reaction vessels and other components of metal or non-metal materials to form a few microns to a few millimeters thick. This kind of tantalum coating has good corrosion resistance, and is widely used in electronic and electrical, chemical, aerospace, medical and health and military fields. At present, the most common methods for preparing tantalum coatings are physical vapor deposition (PVD) and chemical vapor deposition (CVD). The common method of physical vapor deposition is sputtering. Sputtering method is characterized by easy chemical composition control and relatively good adhesion of the deposited coating to the substrate, but the coating obtained by sputtering method has more microcracks, poor mechanical properties and relatively high cost. Moreover, plasma sputtering is suitable for short - range deposition, and it is difficult to deposit complex shape parts. These characteristics limit the application of physical vapor deposition sputtering to a certain extent.
Chemical vapor deposition halide tantalum metal tantalum is usually used as the source, the hydrogen reduction of halogenated tantalum metal tantalum, generated under ordinary conditions required for the reaction temperature is about 1000-1200 ° C, however, due to the reaction temperature is too high, more than the stainless steel and many other heat resistant temperature of substrate material, makes the application of chemical vapor deposition of metal tantalum is limited by many.
