Titanium tube and titanium alloy tube are mainly used in military industry. Paw is not used in bicycle manufacturing for the time being, and then noble and complex chemical processes are carried out. Pure titanium means nothing because it's too soft. To make it useful, titanium is extremely difficult to extract because it has to be isolated. It must be added another metal as an assistant. Of course, the premise of all this is to do it according to the nature of titanium itself. So titanium is usually called an alloy with special properties. From a general point of view, titanium's inferior quality lies in its high strength, high mass ratio (high strength, but light weight), good corrosion resistance, small non-magnetic thermal expansion and thermal conductivity coefficient, high impact toughness (known as metal reducibility by some domestic car drivers) and high fatigue resistance index. In data science, titanium alloy is called allotrope metal because it can show different crystal shapes, such as hexagon or cube. The main difficulty is that titanium is very sensitive to the loss caused by friction. For example, in high speed, if titanium is used in industry, the chain will wear a piece of pure titanium flywheel, just like the reaction produced during welding. If you want to use such a chemical example to explain it, you will understand it more simply, but not to scare people. Although the hexagonal crystal structure of titanium makes its properties excellent, the temperature can change the structure (here is the chemical change, and the physical changes such as thermal expansion and heat conduction do not belong to the same category) because of this reason, titanium is called the saturated crystal structure, because there cannot be a little impurity, even a small content in this titanium alloy. Otherwise, there will be cracks in the welding line of titanium pipe.