Analysis of Physical Properties and Coefficient of Linear Expansion of Titanium Grade 7 alloy

Titanium Grade 7 alloy, a titanium-palladium alloy, is widely used in the chemical industry, aviation and other fields. It is widely recognized for its superior corrosion resistance and strength. Understanding the physical properties of Titanium Grade 7 alloy is crucial for its application. This article will conduct a detailed analysis of its physical properties and linear expansion coefficient.

1.Density and strength
The density of Titanium Grade 7 alloy is approximately 4.51 g/cm³, which is at a relatively low level compared to other titanium alloys. This low-density characteristic makes Titanium Grade 7 alloy an ideal choice for lightweight materials, especially suitable for fields such as aerospace where weight requirements are strict. The strength of Ti-0.2Pd Titanium alloy is moderate, with a tensile strength that can reach 500-600 MPa, and it has good mechanical properties.

2. Thermal Conductivity and Electrical Resistivity
The thermal conductivity of Titanium Grade 7 alloy is relatively low, approximately 16 W/m·K, which results in a smaller thermal expansion in high-temperature environments and enables it to maintain a stable size and shape. The resistivity of Titanium Grade 7 alloy is relatively high, about 0.00055 Ω·cm, indicating that it is not outstanding in electrical conductivity and is suitable for use as a structural material in non-conductive environments.

3. Coefficient of linear expansion
The linear expansion coefficient of Titanium Grade 7 alloy is relatively low, approximately 8.6×10^-6/°C (within the range of 20-100°C). This low linear expansion coefficient results in less structural deformation in environments with temperature variations, making it suitable for high-temperature and high-pressure working conditions, such as nuclear power and chemical equipment. Compared with aluminum alloys (aluminum's linear expansion coefficient is about 23.1×10^-6/°C), the thermal expansion performance of Titanium Grade 7 alloy is more superior, which is beneficial for extending the service life of equipment.

4. Corrosion resistance performance
Due to the addition of palladium, Titanium Grade 7 alloy has excellent corrosion resistance in corrosive environments such as strong acids and strong alkalis. In chemical solutions such as hydrochloric acid, nitric acid, and sulfuric acid, it shows an extremely low corrosion rate and is widely used in marine engineering and petrochemical industries.

Conclusion:
Titanium Grade 7 alloy plays a significant role in fields such as chemical engineering and aerospace due to its excellent corrosion resistance, low linear expansion coefficient and moderate physical strength. Its low density and stable thermal properties make it an ideal choice for high-performance engineering materials.