Carbide coating based on high-melting-point metal and preparation method thereof

Abstract

The invention provides a carbide coating based on high-melting-point metal and a preparation method thereof.The method comprises the steps: preheating a high-melting-point metal workpiece to obtain a pretreated metal workpiece; drying an anhydrous chloride inorganic salt, melting the salt in an inert atmosphere, adding CaC2 to dissolve so as to obtain a molten salt in a molten state; and by taking a graphite electrode as a cathode and the pretreated metal workpiece as an anode, putting the graphite electrode and the pretreated metal workpiece into the molten salt, carrying out electrolysis in a constant current density or constant voltage electrolysis mode, taking out the anode after electrolysis is completed, and cleaning and drying the anode to obtain the carbide coating based on the high-melting-point metal. The high-melting-point metal workpiece serves as the anode, the anhydrous chloride inorganic salt molten salt serves as an electrolyte, CaC2 is added to serve as a carbon source, the anode is subjected to oxidation reaction, carbon ions lose electrons to generate carbon atoms and chemically react with a base material, the tantalum carbide coating is generated on the surface, the carburizing efficiency is high, cracks are not prone to being generated, and the self-cleaning degree is high.

Description

technical field [0001] The invention relates to the technical field of electrochemistry, in particular to a carbide coating based on a high-melting point metal and a preparation method thereof. Background technique [0002] Due to its high melting point, high hardness, and good chemical stability, metal carbides have broad application prospects in aerospace, optical components, alloy strengthening, electrical contact of electronic devices, and biomedicine. Low coefficient of thermal expansion, good electrical and thermal conductivity. The dense film layer can ensure that the substrate has excellent chemical and physical properties, which effectively improves the performance and service life of engineering components. Furthermore, when cemented carbide powders are incorporated into metal-based materials, the mechanical and chemical properties of the host structure can be significantly enhanced. [0003] Traditional and novel methods, such as carbothermal reduction, contact ...

AI Technical Summary

Problems solved by technology

[0005] However, some metals with high melting point and strong passivation are materials that are difficult to carburize. Generally, a high temperature is required for the carburization reaction to occur, and the generated carbides will hinder the further infiltration of carbon elements, which limits the carburization layer. The thickness and carburizing efficiency are low. In various carburizing methods, the temperature of ordinary gas carburizing is too high, which is easy to cause uneven structure, and the carburizing speed is low

On the other hand, the carburized layer on the surface of high-melting point metals often needs to withstand strong corrosion environment, long-term high temperature and repeated thermal shock, which is easy to cause the carburized layer to be not dense, and the bond with the matrix is ​​unstable, and it will be easy to Crack and fall off

Images