The comprehensive performance of titanium alloy ranks first among aviation metal materials , it is the best choice for improving the performance of military aircraft.
On the one hand, the development of military aircraft shows a "lightweight" trend, that is, the structural weight coefficient continues to decrease. Compared with structural steel, under the condition of equal strength, the density of titanium alloy is small, which is only equivalent to 56.25% of structural steel; On the other hand, with the continuous improvement of the flight speed of military aircraft, the temperature of the fuselage surface during high-speed flight continues to increase, and the requirements for the high-temperature resistance of fuselage materials continue to improve. The service temperature of aluminum alloy and magnesium alloy is generally below 300 ℃, while the working temperature of titanium alloy can reach 500-600 ℃.
Therefore, taking the US military aircraft as an example, from the third generation F-16 to the fourth-generation F-22, the amount of titanium alloy used in the military aircraft fuselage increased from 2% to 41%.
Titanium alloy replaced aluminum alloy and became the main material of the F-22 fuselage.
|
Alloy type
|
Bending strength(Mpa) |
Elastic modulus(104 Mpa)
|
Density(g/c) M3 |
specific strength(Mpa/g/cm3)
|
Specific stiffness (104 Mpa/g/cm3) |
|
High strength titanium alloy
|
1646 |
11.76 |
4.5 |
366 |
2.61 |
|
Superhard aluminum alloy
|
588 |
7.154 |
2.8 |
210 |
2.55 |
|
Heat resistant aluminum alloy
|
461 |
7.154 |
2.8 |
165 |
2.55 |
|
High strength magnesium alloy
|
343 |
4.41 |
1.8 |
191 |
2.45 |
|
High strength structural steel
|
1421 |
20.58 |
8 |
178 |
2.57 |
|
Ultra high strength structural steel
|
1862 |
20.58 |
8 |
233 |
2.57 |
