Analysis of Mechanical and Heat Treatment Properties of Ti-6AL-4V Titanium Alloy

TC4 titanium alloy, also known as Ti-6Al-4V alloy, is an α+β type titanium alloy widely used in aerospace, Marine, medical and other fields. It has excellent comprehensive mechanical properties and heat treatment properties. This paper will analyze its mechanical properties and heat treatment properties.

Mechanical properties of TC4 titanium alloy
TC4 titanium alloy has high strength and good plasticity at room temperature. Its tensile strength can reach 900-1100 MPa, yield strength is 800-950 MPa, elongation is between 10% and 15%, and fracture toughness is also good. The density of Ti-6Al-4V alloy is approximately 4.43 g/cm³, which is much lower than that of steel. Therefore, it has an advantage in applications with strict weight requirements, such as aero engines.

TC4 alloy has excellent fatigue performance and strong corrosion resistance, especially suitable for high-strength and corrosion-resistant environments. Its elastic modulus is approximately 110 GPa, which is lower than that of steel. Therefore, in some applications, it can reduce the stiffness requirements of the structure.

2. Heat treatment properties of TC4 titanium alloy
TC4 titanium alloy can improve its mechanical properties and microstructure through different heat treatment processes. Common heat treatment processes include annealing, quenching and aging treatment.

Annealing treatment
Annealing treatment is usually carried out at 700-800℃, with the aim of reducing residual stress and improving the plasticity of the material. After annealing treatment, the tensile strength of TC4 titanium alloy has decreased, but its ductility has increased, making it suitable for applications with high ductility requirements.

(2) Quenching treatment
The quenching treatment temperature of TC4 titanium alloy is generally 930-950℃. After water cooling or air cooling, a martensitic structure will be formed, significantly enhancing the material's strength. At this point, the tensile strength can reach over 1100 MPa, but the toughness will decline somewhat.

(3) Aging treatment
After quenching, TC4 titanium alloy is usually subjected to aging treatment, with a temperature range of 480-600℃. After aging treatment, the hardness and strength of the alloy are further enhanced, making it particularly suitable for structural components that require high strength.

3. The influence of heat treatment on the microstructure of TC4 alloy
Different heat treatment processes have a significant influence on the microstructure of TC4 alloy. Annealing treatment will generate a relatively uniform α+β phase; While quenching treatment forms needle-like martensite; Aging treatment is conducive to the formation of precipitation strengthening phases, and these structural changes directly affect the mechanical properties of the alloy.

4. Summaryv TC4 titanium alloy has become one of the preferred high-performance structural materials due to its excellent mechanical properties and adjustable heat treatment performance. By rationally choosing the heat treatment process, its strength, toughness and plasticity can be significantly improved to meet the demands of different application fields.