For a long time, the materials used in the pressure-resistant shell sonar shrouds and piping systems of our naval vessels are basically carbon steel, aluminum alloy, and stainless steel. It is worth noting that Russia (the former Soviet Union) also used these conventional materials, but then most of them switched to titanium alloys, and the final application effect was good.
For example, the K166 nuclear submarine built at the end of 1968, its hull, piping system and a large number of other devices and machinery are made of titanium alloys. And in the early 1970s, the A-class attack nuclear submarine, which attracted worldwide attention, was the smallest nuclear submarine in the world at that time with the smallest tonnage (underwater displacement of 3120t), the fastest sailing speed (underwater maximum speed of 41kn), and the deepest dive. (The diving depth is 700m, the limit diving depth is 750m), the most advanced nuclear submarine is also constructed using titanium alloy as the main material.
Russia and Ukraine have skilled labor and sophisticated test equipment, and have produced many types of underwater vehicles, such as MIR2, URAN-1, MASK-2, etc. Among them, advanced shells such as titanium alloys derived from spacecraft Materials technology is their forte.
In addition to Russia and Ukraine, other countries have also carried out research in the field of titanium alloy applications. The United States began the research and application of titanium alloy submersibles in the 1960s. The "Sea Cliff" submersibles built in 1981 and 1982 were equipped with observation and manipulation cabins made of titanium alloys. The main structures of the "Nautilus" submersible developed by France in 1985, the Japanese "Deep Sea 6500" survey submersible, the "Jiaolong" manned submersible and the "Orange Shark" autonomous underwater vehicle independently developed by my country Components are made of titanium alloy.
Titanium alloys have also made new breakthroughs in the research field of large-scale and deep-dive vehicles in my country. Due to its good mechanical properties, long service life and low maintenance costs, the application of titanium alloys in submarines has obvious advantages, especially for the shell materials of large diving depth equipment, which not only need to have both extremely high strength and good toughness, In addition, it needs to have better anti-corrosion, sound transmission, non-magnetic and other comprehensive characteristics, so the research and application of high-performance titanium alloy materials is the main development trend, and there have been certain technological breakthroughs.
Dalian University of Technology Wang Lei et al. proposed a cylindrical synchronous permanent magnet thruster used in underwater robots. The isolation sleeve is made of titanium alloy materials. Hu Ren of Zhejiang University determined that titanium alloys are used as water-resistant materials through the analysis of the pressure resistance of different materials. The pressure-resistant shell material of the glider, the 7000m deep-sea glider sealing head end cover supported by the pilot project of the Chinese Academy of Sciences is also made of titanium alloy.
Titanium alloys have outstanding performance in the field of manned deep diving. The "Deep Sea Warrior" manned submersible independently developed by my country has a maximum working depth of 4500m, and the "Jiaolong" manned submersible has successfully submerged 7000m. "No." manned submersible successfully won the "Fourth Pole of the Earth" in the Mariana Trench, with a bottom depth of 10909m. The pressure shells of these types of submersibles are made of high-strength titanium alloy materials, and other main structures are also made of titanium alloy materials. It can be said that titanium alloys have played a huge role in the current field of new underwater vehicles in my country, and will also play a positive role in the research and development of high-performance vehicles in the future.