Industrial pure titanium and titanium alloys have the characteristics of corrosion resistance, high temperature resistance and high specific strength. Because of the addition of other alloying elements, titanium alloys have more diverse properties and wider uses than industrial pure titanium.
1. Corrosion resistance
Titanium and titanium alloys have good corrosion resistance in different media and different temperature conditions. Especially in seawater, the corrosion resistance is better than that of aluminum alloy, stainless steel and nickel-based alloys.
The corrosion resistance of titanium comes from passivation. In the atmosphere or in an aqueous solution, the surface of titanium will immediately form a well-protected oxide film (passivation film). This layer of oxide film has a very good healing property, after mechanical damage can be quickly (<0.1s) healed to form a new film. At temperatures below 315℃, the oxide film of titanium always maintains this characteristic.
2. High temperature resistance
Industrial pure titanium and titanium alloys can maintain good strength and performance under high temperature environment. Pure titanium is slightly lower and can be stable in service below 350℃; The operating temperature of titanium alloy can reach 500℃ or even higher.
3. High specific strength
Industrial pure titanium and titanium alloys have high specific strength. Specific strength refers to the ratio of strength to density of a material. High specific strength means that the material is strong and light in weight. Such features are popular in the aerospace industry.
Aircraft or spacecraft commonly used materials are stainless steel, nickel-based alloys and aluminum alloys. Compared with stainless steel and nickel-based alloys, titanium alloys are about half as dense and lighter; Compared with aluminum alloy, which can only work below 200℃, titanium alloy is more resistant to high temperature. The advantages are obvious.
