GR5 titanium alloy, also known as T titanium alloy or 6Al4V, is the most widely used type of titanium metal. It possesses excellent ductility and elongation.
Titanium and its alloys have many advantages such as lightweight, high strength, excellent heat resistance, and corrosion resistance, making them regarded as the "metal of the future" and a promising new structural material. They are extensively used not only in the aerospace and space industries but also in industries such as chemical engineering, petroleum, light industry, metallurgy, and power generation. Titanium can resist corrosion from the human body and is harmless to it, thus finding extensive applications in the medical and pharmaceutical industries. Titanium also exhibits good gas absorption properties and finds wide applications in electronic vacuum technology and high vacuum technology.
The density of metallic titanium is 4.51g/cubic centimeter, higher than aluminum but lower than steel, copper, and nickel, yet its strength ranks first among metals.
Titanium is a very active metal with a low equilibrium potential, indicating a high thermodynamic corrosion tendency in media. However, titanium is stable in many media. In oxidizing, neutral, and weak reducing media, titanium exhibits corrosion resistance. This is because titanium has a strong affinity with oxygen, forming a dense, strongly adherent, and inert oxide film on its surface in air or oxygen-containing media, protecting the titanium substrate from corrosion. Even if mechanically worn, it can quickly self-repair or regenerate. This demonstrates titanium's strong passivation tendency. The oxide film of titanium maintains this characteristic when the medium temperature is below 315°C. To enhance titanium's corrosion resistance, surface treatment techniques such as oxidation, electroplating, plasma spraying, ion nitriding, ion implantation, and laser treatment have been developed, enhancing the protective effect of the oxide film on titanium and achieving the desired corrosion resistance effect. A series of corrosion-resistant titanium alloys such as titanium-molybdenum, titanium-palladium, and titanium-molybdenum-nickel have been developed to meet the needs of metal materials in production environments such as sulfuric acid, hydrochloric acid, methylamine solution, high-temperature wet and high-temperature chloride. For example, titanium castings use titanium-32 molybdenum alloy, titanium-0.3 molybdenum-0.8 nickel alloy is used in environments prone to crevice corrosion or pitting corrosion, and titanium-0.2 palladium alloy is used locally in titanium equipment, all of which have achieved good results.
New titanium alloys can be used for long periods at temperatures of 600°C or higher.
Low-temperature titanium alloys such as TA7 (Ti-5Al-2.5Sn), T (Ti-6Al-4V), and Ti-2.5Zr-1.5Mo have increasing strength with decreasing temperature, but with little change in plasticity. They maintain good ductility and toughness at temperatures ranging from -196°C to 253°C, avoiding metal brittleness, making them ideal materials for low-temperature containers, tanks, and other equipment.
Titanium has the longest self-vibration damping time among metals such as steel and copper when subjected to mechanical or electrical vibrations. This property of titanium can be utilized in applications such as tuning forks, vibration elements in medical ultrasonic crushers, and vibrating membranes in high-end audio speakers.
Titanium is a non-magnetic metal that does not magnetize even in large magnetic fields. It is non-toxic and has good compatibility with human tissues and blood, making it widely used in the medical field.
This property of titanium indicates a high yield strength ratio (tensile strength/yield strength), suggesting poor plastic deformation of titanium materials during forming. The large ratio of titanium's yield limit to its elastic modulus enables it to exhibit significant rebound capacity during forming.
Although the thermal conductivity of metallic titanium is lower than that of carbon steel and copper, its excellent corrosion resistance allows for significant reduction in wall thickness. Moreover, the heat transfer mode between the surface of titanium and steam is dropwise condensation, reducing the heat transfer resistance. The surface of titanium does not scale, further reducing heat resistance, significantly improving the heat transfer performance of titanium.
The modulus of elasticity of titanium is 106.4 GPa at room temperature, which is 57% that of steel.
Titanium is a chemically very active metal that can react with many elements and compounds at high temperatures. Titanium gas absorption mainly refers to reactions with carbon, hydrogen, nitrogen, and oxygen at high temperatures.