Application of titanium in American spacecraft

Astronauts can ride in the sealed cabin. The inner skin is welded with pure Titanium Sheet with a thickness of 0.25mm. The rib for reinforcement is ti-5al-2.5sn titanium alloy extrusion, which has medium mechanical strength. Part of the skeleton ring is made of Ti-6Al-4V alloy, and the inner skin plate is welded on it. Ti-6Al-4V is one of the most widely used titanium alloys. It is a very comprehensive alloy. It not only has high mechanical properties, but also can be used at 480 ℃ for a long time. It has high heat resistance, good weldability and excellent air tightness of the weld, which is very beneficial to regulating the pressure in the cabin. This kind of spacecraft is launched by Atlas rocket. Many structural parts of the rocket, such as reinforcing ring and connecting ring, are made of titanium alloy. Composition of ti-5al-2.5sn alloy: al4.5-5.75, sn2.0-3.0, fe0.50, c0.08, n0.05, h0.020, O0.20.

The spacecraft must slow down when re entering the atmosphere. This task is completed by four circular rockets loaded with solid fuel. Each rocket has two Ti-6Al-4V welded titanium alloy semi-circular spheres, with a material thickness of 1.0mm and a deviation of + 0.17mm, - 0.01mm. The oxygen cylinder in the passenger compartment is made of Ti-6Al-4V or ti-13v-11cr-3al titanium alloy. The oxygen cylinder has a volume of 2.5L, a pressure of 2059mpa and a mass of 160kg.

The tower structure of the launch traction system is made of titanium alloy. The liquid hydrogen container and conduit of the command module and machinery module and the low-temperature container of the lunar module are made of Ti-6Al-4V alloy. The container in the descending part of the lunar module needs to have greater plasticity, so it is made of ti-5al-2.5sn alloy[ Apollo spacecraft has more than 40 pressure vessels, about 85% of which are made of titanium alloy. Nitrogen tetroxide, helium, nitrogen and fuel containers are made of Ti-6Al-4V and ti-5al-2.5sn alloys. Because ti-5al-2.5sn alloy has high toughness at - 252.7 ℃, liquid hydrogen and supercritical helium containers are made of this alloy.

The space shuttle is a means of transportation between the ground and the space station, so it is also called the space ferry. It is required to be used for many times, preferably up to 100 times or more. When it enters the atmosphere, the temperature of the upper half of its fuselage and wing can reach 180 ℃ - 815 ℃. Therefore, the components of some parts need to be made of heat-resistant titanium alloy, for example, Ti / B-Al composite material for the upper body frame, tail, the wing beams and ribs are made of titanium alloy. The oil pressure piping is Ti-3Al-2.5V alloy seamless pipe, which reduces the mass of the system by more than 40%. In order to reduce the sensitivity to fatigue fracture and improve the service life of the system, the forming and assembly of various pipe fittings are automated.