This is a highly professional and cutting-edge field. Unlike thick plates or forgings used for main structural components, the application of titanium alloy foils (typically referring to ultra-thin strips with a thickness of no more than 0.1mm) is more focused on functionality, lightweighting and system integration.
The multi-layer insulation structure is the most classic and important application of titanium alloy foil in spacecraft.
Working principle: When a spacecraft is in orbit, the side facing direct sunlight is extremely hot, while the side in the shade is extremely cold. MLI is like an "insulating blanket" or "life-saving blanket" for spacecraft, used to keep the instruments and equipment inside the cabin within a stable temperature range. It is composed of dozens or even hundreds of extremely thin (usually 5-20 microns) titanium alloy foils or aluminum foils, with each layer separated by sparse mesh materials, which greatly reduces heat exchange through thermal radiation and conduction.
Extremely low thermal emissivity: The titanium foil with its surface treated has a very low thermal emissivity coefficient and can efficiently reflect thermal radiation.
High melting point and stability: Compared with plastic films, titanium foil can withstand higher temperatures (for example, in low Earth orbit or areas close to engines) and will not release air to contaminate sensitive optical equipment.
Resistance to atomic oxygen erosion: Atomic oxygen (AO) exists in low Earth orbit (LEO), which can erode many organic materials. A stable protective layer of titanium oxide forms on the surface of titanium foil, which has excellent resistance to atomic oxygen erosion.
Application parts: Widely used for the external wrapping of various satellites, space probes, manned spacecraft, as well as insulation of cryogenic fuel storage tanks.
