Tantalum and tantalum alloy have the advantages of high melting point, good corrosion resistance, excellent high temperature strength, good machining performance, weldable performance, low plastic/brittle transition and excellent dynamic mechanical properties. It is widely used in electronics, weapons, chemical industry, aerospace industry and space nuclear power system and other industries. It is an ideal structural material working in the environment of 1600 ℃~1 800 ℃. Although tantalum and tantalum alloy have excellent mechanical properties at high temperature, their oxidation resistance is poor at high temperature. Molybdenum will accelerate oxidation to Ta205 above 500℃. Due to the above characteristics, the application of tantalum and tantalum alloy is severely restricted. It is very important to expand the application scope of tantalum and tantalum alloy to improve its high temperature resistance and oxidation resistance. There are two main methods to protect tantalum and tantalum alloy against high temperature and oxidation resistance: 1. Surface coating against high temperature and oxidation resistance protection 2. Alloying against high temperature and oxidation resistance protection.
Although the alloying method can improve the antioxidant properties of tantalum and tantalum alloy, the precondition is that the amount of alloying elements must reach the critical value to protect the matrix. At the same time, it will have a great influence on other properties of the matrix, especially the mechanical properties of the matrix at high temperature.
Surface coating can have lower oxygen permeation ability at the same time, good chemical and physical compatibility and stability, low volatility, good thermal expansion coefficient matching and combining ability, high temperature self healing ability and cannot affect tantalum alloy base material original advantages such as good mechanical properties is solve tantalum alloy high temperature mechanical properties and oxidation resistance of the best method.
So far, the surface high temperature antioxidant coating systems of tantalum and tantalum alloy materials that have been studied mainly include precious metal high temperature antioxidant coating, ceramic high temperature antioxidant coating and composite antioxidant coating. The new research progress of various high temperature antioxidant coatings of tantalum and tantalum alloy are summarized in the following.
