Titanium pipe is a new type of metal material, which has completely replaced traditional iron pipes and steel pipes in some aspects. So, what is it that allows it to spread so quickly and replace traditional tubes?
1. The specific strength of titanium tube is high. The density of titanium alloy is generally about 4.5g/cm3, which is only 60% of steel, and the strength of pure titanium is close to the strength of ordinary steel, and some high-strength titanium alloys exceed the strength of many alloy structural steels. Therefore, the specific strength (strength/density) of titanium alloy is much greater than that of other metal structural materials, and parts with high unit strength, good rigidity and light weight can be produced. At present, titanium alloys are used in the engine components, skeletons, skins, fasteners and landing gear of aircraft.
2. The thermal strength of titanium tube is high. The operating temperature is hundreds of degrees higher than that of aluminum alloy, and it can still maintain the required strength at medium temperatures, and can work for a long time at a temperature of 450~500 °C. These two types of titanium alloys still have high specific strength in the range of 150°C~500°C, while the specific strength of aluminum alloys decreases significantly at 150°C. The operating temperature of titanium alloys can reach 500°C, while aluminum alloys can reach below 200°C.
3. The corrosion resistance of titanium tube is good. Titanium alloy works in humid atmosphere and seawater medium, and its corrosion resistance is much better than that of stainless steel, and its resistance to pitting, acid etching, and stress corrosion is particularly strong, and it has excellent corrosion resistance to alkali, chloride, chlorine organic matter, nitric acid, sulfuric acid, etc.
4. The low temperature performance of titanium tube is good. Titanium alloys can still maintain their mechanical properties at low and ultra-low temperatures. Titanium alloys with good low-temperature properties and very low interstitial elements, such as TA7, can maintain a certain plasticity at -253 °C. Therefore, titanium alloy is also an important low-temperature structural material.
5. The chemical activity of titanium tube is large. Titanium has great chemical activity and produces strong chemical reactions with O, N, H, CO, CO2, water vapor, ammonia, etc. in the atmosphere. When the carbon content is greater than 0.2%, hard TiC will be formed in the titanium alloy, and when the temperature is high, the hard surface layer of TiN will also be formed by the interaction with N, and when the carbon content is above 600°C, titanium will absorb oxygen to form a hardened layer with high hardness, and a brittleness layer will also be formed when the hydrogen content increases. Titanium also has a high chemical affinity, and it is easy to adhere to friction surfaces.
6. The thermal conductivity of titanium tube is small and the elastic modulus is small. The elastic modulus of titanium alloy is about 1/2 of steel, so its rigidity is poor, easy to deform, and it is not suitable to make slender rods and thin-walled parts, and the rebound amount of the machined surface is very large during cutting, which is about 2~3 times that of stainless steel, resulting in severe friction, adhesion, and bonding wear on the flank surface of the tool.
Titanium tube is deeply loved by people from all walks of life because of its light weight, easy to use, good performance, small density and other advantages, and is widely used. It plays an important role in aircraft engines, rockets, and missiles.