Titanium and aviation are inextricably linked. In 1953, the DC-T engine pods and fire walls produced by Douglas Company were first made of titanium, thus revealing the history of titanium aviation applications. Since then, titanium has been used in aviation for more than half a century. Titanium is widely used in aviation because it has many valuable characteristics suitable for aircraft applications. Today we're going to talk about why we have to use titanium for aerospace materials.
High strength: 1.3 times of aluminum alloy, 1.6 times of magnesium alloy, 3.5 times of stainless steel, the champion of metal materials.
High thermal strength: the service temperature is several hundred degrees higher than that of aluminum alloy, which can work for a long time at the temperature of 450 ~ 500℃.
Good corrosion resistance: acid resistance, alkali resistance, atmospheric corrosion, especially strong resistance to pitting corrosion, stress corrosion.
Good low temperature performance: Titanium alloy Ta7 with very low interstitional elements can maintain a certain degree of plasticity at -253℃.
Chemical activity is big: chemical activity is very high when high temperature, produce chemical reaction easily with the gas impurity such as hydrogen in air, oxygen, generation hardened layer.
Small thermal conductivity and elastic modulus: the thermal conductivity is about 1/4 of nickel, 1/5 of iron and 1/14 of aluminum, while the thermal conductivity of various titanium alloys is about 50% lower than that of titanium. The elastic modulus of titanium alloy is about 1/2 that of steel.
Titanium alloys can be divided into heat-resistant alloys, high-strength alloys, corrosion-resistant alloys (Titanium-Molybdenum, Titanium-Palladium alloys, etc.), cryogenic alloys and special functional alloys (titanium-iron hydrogen storage materials and Titanium-Nickel memory alloys).
Although titanium and its alloys have a short history of application, they have won many honorable titles due to their superior performance. The first to win the title is "space metal". Its light weight, high strength and high temperature resistance, especially suitable for the manufacture of aircraft and various spacecraft. About three-quarters of the world's titanium and titanium alloys are used in the aerospace industry. Many parts originally made of aluminum alloy have been made of titanium alloy.
