With the widespread use of titanium alloys in power systems, their excellent specific strength, heat resistance, corrosion resistance, and low-density properties have revolutionized the aviation, aerospace, naval, and chemical industries. However, surface protection of titanium alloys is particularly important during processing, assembly and use, as titanium alloys are extremely sensitive to surface damage and have a number of inherent weaknesses.
Weaknesses and risks of titanium alloys
Titanium alloys face a variety of potential risks during processing and use. Its blades are susceptible to damage during machining and polishing, and damage to surface integrity can significantly reduce the fatigue performance of the part. In addition, titanium alloys are poorly resistant to contamination and susceptible to galvanic corrosion when in contact with certain metals. Its low hardness, poor wear resistance, and sensitivity to hot salt stress corrosion are characteristics that are more likely to cause serious accidents in power systems, especially when serving in the marine environment.
Titanium alloy processing process protection requirements
In order to ensure the integrity and performance of titanium alloy parts, a series of protective measures need to be taken during processing. First of all, the cutting process should use rigid machine tools, cutting tools, and special tooling with low vibration and strong rigidity. The surface of the workpiece shall not have active metal plating to prevent galvanic corrosion. The cutting depth should exceed the thickness of the cold work hardening layer, and the tool needs to have wear resistance and high thermal hardness.
Surface protection during heat treatment of titanium alloys
Heat treatment of titanium alloy is a key step to eliminate residual stress and improve performance. In the heat treatment process, the surface of titanium alloy should never have contaminants such as oil, fingerprints and so on. Heat treatment fixtures need to be made of stainless steel or high-temperature alloys, and the surface needs to be kept clean. For finishing titanium alloy parts, heat treatment must be carried out in a vacuum furnace or under argon protection to prevent oxidation.
Protection against hydrogen embrittlement in chemical processing of titanium alloys
Hydrogen embrittlement is a common risk in chemical processing of titanium alloys. To prevent hydrogen embrittlement, it is necessary to use effective anti-hydrogen coatings during the heat treatment processing of titanium alloys, and to remove hydrogen promptly after treatment. Hydrogen is an extremely hazardous impurity in titanium alloys with a small diffusion coefficient that does not easily escape from the coating, so strict measures are needed to prevent excessive hydrogen absorption.
Summarize
Surface protection of titanium alloys in power systems is a crucial task. By adopting appropriate processing and heat treatment measures, as well as the use of effective anti-hydrogen coatings, the risks of titanium alloy parts during processing and use can be significantly reduced, ensuring the stability and reliability of their performance.
