Abstract:

Low density, higher than strength

The density of titanium is 4.51g/cm3, higher than aluminum but lower than steel, copper, nickel, but the specific strength is in the first metal.

Corrosion resistance

Titanium is a very active metal with low equilibrium potential and high thermodynamic corrosion tendency in media. But in fact titanium in many media is very stable, such as titanium in oxidation, neutral and weak reducing media is corrosion resistant. This is because titanium and oxygen have a great affinity, in the air or oxygen-containing medium, titanium surface generates a layer of dense, strong adhesion, inert oxide film, protect the titanium matrix from corrosion. They heal or regenerate quickly even due to mechanical wear. This indicates that titanium is a metal with a strong tendency to passivate. The oxide film of titanium always keeps this property when the temperature of the medium is below 315℃.

In order to improve the corrosion resistance of titanium, surface treatment technologies such as oxidation, electroplating, plasma spraying, ion nitriding, ion implantation and laser treatment have been studied, which enhanced the protective effect of titanium oxide film and obtained the desired corrosion resistance effect. A series of corrosion-resistant titanium alloys, such as ti-molybdenum, ti-palladium, ti-molybdenum and nickel, have been developed to meet the needs of metal materials in the production of sulfuric acid, hydrochloric acid, methylamine solution, high temperature wet chlorine and high temperature chloride. Ti-32 molybdenum alloy is used in titanium castings, ti-0.3 molybdenum-0.8 nickel alloy is used in the environment where crevice corrosion or pitting corrosion often occurs, and ti-0.2 palladium alloy is used in parts of titanium equipment.

Good heat resistance

The new titanium alloy can be used for a long time at temperatures of 600℃ or higher.

Good low temperature resistance

The strength of low temperature titanium alloys TA7 (Ti-5Al-2.5Sn),TC4(Ti-6Al-4V) and Ti-2.5Zr-1.5Mo increases with decreasing temperature, but the plasticity changes little. Keep good ductility and toughness at low temperature of -196-253℃, avoid metal cold brittleness, is the ideal material for low temperature containers, storage tanks and other equipment.

Strong anti-damping performance

Compared with steel and copper, titanium has the longest vibration attenuation time when subjected to mechanical and electrical vibration. The performance of titanium can be used as tuning fork, vibration element of medical ultrasonic crusher and vibration film of advanced loudspeaker.

Non-magnetic, non-toxic

Titanium is a non-magnetic metal and will not be magnetized in a large magnetic field. It is non-toxic and has a good compatibility with human tissues and blood, so it is used in the medical field.

The tensile strength is close to its yield strength

This performance of titanium shows that its yield strength ratio (tensile strength/yield strength) is high, indicating that the plastic deformation of metallic titanium material is poor during forming. As the ratio of yield limit to elastic modulus of titanium is large, the resilience of titanium is large.

Good heat exchange performance

Although the thermal conductivity of titanium is lower than carbon steel and copper, but because of the excellent corrosion resistance of titanium, so the wall thickness can be greatly reduced, and the heat transfer mode of the surface and steam is drip condensation, reducing the heat group, too the surface without scaling can also reduce the thermal resistance, so that the heat transfer performance of titanium is significantly improved.

Low elastic modulus

The elastic modulus of titanium is 106.4GMPa at room temperature, which is 57% of steel.

Breathe in performance

Titanium is a chemically active metal that can react with many elements and compounds at high temperatures. Titanium inhalation mainly refers to the reaction with carbon, hydrogen, nitrogen and oxygen at high temperature.