Development and application of titanium alloys

Titanium alloy, with its unique physical and chemical properties, has become an indispensable material in many fields such as aviation, aerospace, automotive, chemical and medical. From the initial high-temperature titanium alloys to today's medical titanium alloys, the development and application of titanium alloys continue to make new breakthroughs.
I. Breakthroughs in high-temperature titanium alloys
The world's first successfully developed high-temperature titanium alloy is Ti-6Al-4V, which can be used at temperatures up to 300-350℃. Subsequently, with the advancement of technology, higher temperature titanium alloys have been introduced, such as IMI550, BT3-1 and other alloys using temperature up to 400 ℃, while IMI679, IMI685, Ti-6246, Ti-6242 and other alloys can be in the 450-500 ℃ high temperature and stable work. At present, new high-temperature titanium alloys that have been applied to aircraft engines include IMI829 and IMI834 alloys of the United Kingdom, Ti-1100 alloys of the United States, and BT18Y and BT36 alloys of Russia.
In order to further improve the use of titanium alloy temperature, foreign countries are actively using rapid solidification / powder metallurgy technology, fiber or particle reinforced composite materials and other new technologies to develop titanium alloys that can work at high temperatures above 650 ℃. For example, the U.S. McDonnell Douglas Company has successfully developed a high-purity, high-density titanium alloy using rapid solidification/powder metallurgy technology, which still maintains excellent strength at 760℃.

Second, the rise of titanium aluminum compound-based titanium alloy
Titanium aluminum compound-based titanium alloys, such as Ti3Al (α2) and TiAl (γ) intermetallic compounds, with its high-temperature performance, oxidation resistance, creep resistance and light weight, etc., to become the future of aero-engine and aircraft structural components competitive materials. Currently, there are Ti3Al-based titanium alloys such as Ti-21Nb-14Al and Ti-24Al-14Nb-#v-0.5Mo, which have begun mass production in the United States. And TiAl (γ)-based titanium alloys, such as TAl-(1-10)M (at.%), have also received widespread attention because of their unique properties.
Third, the development of β-type titanium alloy
β-type titanium alloys are characterized by good hot and cold processing performance, easy forging, rolling and welding, and are important materials in aerospace, automotive and other fields. Representative β-type titanium alloys include Ti1023, Ti153, β21S, etc., which not only have excellent mechanical properties and environmental resistance, but also have high strength, high toughness and other characteristics.
Fourth, the innovation of medical titanium alloy
Titanium is non-toxic, lightweight, high strength and has excellent biocompatibility, it is an ideal metal material for medical use. At present, Ti-6Al-4v ELI alloy is widely used in the medical field, but its possible precipitation of vanadium and aluminum ions on the human body may cause harm has aroused the concern of the medical community. For this reason, aluminum-free, vanadium-free, biocompatible titanium alloys are being actively developed. For example, Japan has developed a series of α + β titanium alloys and β titanium alloys with excellent biocompatibility, which are expected to replace Ti-6Al-4V ELI alloys in the future and become the mainstream materials for medical implants.