Ti-6Al-4V titanium alloy, as an important part of the titanium alloy TC4 material, has won a wide range of applications for its excellent comprehensive mechanical and mechanical properties. Its high strength and moderate density make it a significant advantage in various engineering applications.
The strength sb of TC4 titanium alloy reaches 1.012GPa, while its density g is 4.51g/cm3, making the ratio of strength to density sb/g reach 23.5. This value is much higher than that of alloy steel, which shows its excellent strength and lightweight characteristics.
The low thermal conductivity of titanium alloys is due to their crystal structure and chemical composition. Compared with iron, the thermal conductivity of titanium alloy is only 1/5 of that of iron. in TC4 titanium alloy, its thermal conductivity is 1/10/7.955W/m-K, further proving its good thermal insulation performance.
In addition, the coefficient of linear expansion and specific heat capacity of TC4 titanium alloy also show their unique characteristics. The coefficient of linear expansion is 8.6*10-6°C (0-100°C) and the specific heat is 0.612j/g-°C. These properties make the titanium alloy susceptible to deformation during machining, and special attention is required to control the machining temperature and stress.
In terms of elastic properties, the modulus of elasticity E of TC4 titanium alloy is 110GPa, which is about 1/2 of that of steel. this makes the titanium alloy maintain good elasticity when subjected to large deformations, and provides a broad design space for engineering applications.
In addition, TC4 titanium alloy has good corrosion resistance. Working in humid atmospheric and seawater media, its corrosion resistance is much better than stainless steel. Strong resistance to pitting, acid corrosion, intergranular corrosion. It also has good corrosion resistance to alkali, fluoride, chlorine, nitric acid, hydrochloric acid and other organic substances. However, it should be noted that titanium has poor corrosion resistance to oxidized oxygen and chromium salt media.
Titanium alloys also maintain their good mechanical properties at low temperatures. For example, the TA7 titanium alloy retains some plasticity at low temperatures. Therefore, titanium alloy is also an important low temperature structural material.
It is worth mentioning that titanium alloy also has a large chemical activity. It reacts strongly with O, N, H, CO, CO2, water vapor, ammonia and other chemicals in the air. This property makes titanium alloys prone to adhesion when in contact with friction surfaces.
In order to improve the surface properties of titanium alloys, researchers used ion injection technology for surface modification. The experimental results show that the microhardness of the titanium alloy treated by ion injection increases, the coefficient of sliding friction is significantly reduced, and the wear resistance is effectively improved. In order to further understand the modification mechanism, the researchers used X-ray photoelectron spectroscopy to analyze the injected and uninjected samples and obtained satisfactory results.
