Titanium is an important structural metal developed in the 1950s. Titanium alloys are alloys based on titanium with other elements added. Titanium alloys are widely used due to their high strength, good corrosion resistance, and high heat resistance Used in various fields. Many countries in the world have realized the importance of titanium alloy materials, and have successively researched and developed them, and have obtained practical applications. From the 1950s to the 1960s, it was mainly to develop high-temperature titanium alloys for aircraft engines and structural titanium alloys for airframes. A batch of corrosion-resistant titanium alloys was developed in the 1970s. Since the 1980s, corrosion-resistant titanium alloys and high-strength titanium alloys have been further developed. development of. Titanium alloy is mainly used to make aircraft engine compressor components, followed by rocket, missile and high-speed aircraft structural parts.

Titanium and titanium alloys have many excellent characteristics, mainly reflected in the following aspects:

1. High strength. Titanium alloy has high strength, its tensile strength is 686-1176MPa, and the density is only about 60% of steel, so the specific strength is very high.
2. High hardness. The hardness HRC of the titanium alloy (annealed state) is 32-38.
3. Low elastic modulus. The elastic modulus of titanium alloy (annealed state) is 1.078 × 10－1.176 × 10MPa, which is about half of steel and stainless steel.
4. Excellent high and low temperature performance. At high temperatures, titanium alloys can still maintain good mechanical properties, their heat resistance is much higher than aluminum alloys, and the working temperature range is wider. At present, the working temperature of new heat-resistant titanium alloys can reach 550-600 ℃; at low temperatures However, the strength of the titanium alloy is increased compared to that at room temperature, and it has good toughness. The low-temperature titanium alloy can maintain good toughness at -253 ° C.
5. Titanium has strong corrosion resistance. Titanium quickly forms a thin and dense titanium oxide film in the air below 550 ° C, so its corrosion resistance is superior to most stainless steels in oxidizing media such as the atmosphere, seawater, nitric acid, sulfuric acid, and strong alkalis.