Titanium has been discovered for more than 200 years since the end of the 18th century. However, due to its high melting point and very active chemical properties, it is difficult to make pure titanium with good plasticity. Titanium ingot must be smelted in vacuum, and the manufacturing process is complicated in the process of smelting, so that titanium and its alloy cannot be widely used in industrial production and industrial construction for a long time. With the continuous development of science, technology and economy, further exploration and research have been made on the materials involved in the development of aerospace, thus promoting the rapid development of the titanium industry. The metal properties of titanium and titanium alloy determine the main application and development of titanium alloy. To sum up, titanium and titanium alloy mainly have the following metal characteristics:
Firstly, compared with other composite materials, titanium is characterized by low density and high strength. Its density is just between aluminum and iron, but titanium alloys are much stronger and more ductile than aluminum and steel.
Second, titanium alloy in the process of use and the degree of temperature is relatively wide, so in the process of processing and use, when the temperature down to 200 ℃, it can still maintain the original shape, while in the state of high temperature processing or in high temperature environment in use process, it is under high temperature can reach 500 ℃, thus it can be seen, in the heat degree is much higher than aluminum and magnesium alloys. It may be further developed if, during use and processing, environmental pollution caused by oxidation can be avoided or prevented at higher temperatures.
Thirdly, titanium and titanium alloy also have excellent corrosion resistance, especially in seawater and atmospheric environment, which makes the application of titanium and titanium alloy in ships and aircraft have greater competitiveness.
Fourthly, titanium has very high chemical properties, and it is very vulnerable to pollution problems caused by hydrogen, oxygen and nitrogen in the process of high-temperature processing, which makes it subject to constraints and restrictions in the smelting and processing process, thus making the production cost relatively high.
Fifthly, compared with other composite materials, titanium alloy has poor thermal conductivity and relatively low anti-wear performance. As a result, in the working process of cutting, can not avoid due to the workpiece and tool temperature rise caused by the phenomenon of sticky knife.