Research Status And Development Trend Of Titanium Alloy Corrosion At Home And Abroad

Titanium alloys are difficult to process, which restricts their application to a certain extent. The emergence of titanium alloy corrosion processing technology will further broaden the application prospects of titanium alloys. At present, in foreign countries, titanium alloy corrosion processing has been used as a general processing method to reduce the quality of aircraft structure, and corrosion processing technology has been developed rapidly.

Titanium alloy corrosion processing technology is a new technology developed in the 1950s. In the 1970s, the subject of chemical corrosion processing has been reported in relevant literature in developed countries, and my country has been paying attention to this research field since the 1980s. Due to patents and confidential content, there are few reports and books in this area. In the early days, the most widely used titanium etching solution in the United States was a mixed solution based on hydrofluoric acid and chromic acid, and a mixed solution of hydrofluoric acid and nitric acid was used in the United Kingdom. However, chromic acid-containing solutions are generally not used in foreign countries. In addition to the inherent pollution due to its high cost, the more important thing is that hydrogen embrittlement will occur when using this solution, resulting in poor mechanical properties of the processed materials.

There is a certain gap between domestic and foreign developed countries in the application of titanium alloys. The number of titanium alloy parts used is limited, and the titanium alloy corrosion processing technology has not yet had a complete industrial chain and is in its infancy. Due to the needs of national defense, researchers in our country have begun to pay attention to the research on the corrosion processing of titanium and its alloys. The research on the corrosion processing technology of TC1 and TC4 titanium alloys by Nanchang Aviation University is relatively mature. It has the characteristics of low environmental pollution and low surface roughness value. The common corrosion processing fluids in China are hydrofluoric acid type, hydrofluoric acid-nitric acid type, hydrofluoric acid-chromic acid type and silicofluoric acid type.

At present, titanium alloy corrosion processing technology has been applied in a small amount of production in China, mainly in aero-engine factories and main engine assembly plants and other companies that use titanium alloys. As an auxiliary processing method, it has not been widely used.