Main characteristics and uses of titanium materials

Iodine method titanium:

This is high-purity titanium obtained by the iodide method,hence it is called iodine method titanium,or chemically pure titanium.However,there are still interstitial impurities such as oxygen,nitrogen,and carbon,which have a significant impact on the mechanical properties of pure titanium.As the purity of titanium increases,its strength and hardness significantly decrease.The characteristic is that the chemical stability is good,but the strength is very low.

Industrial pure titanium:

The difference between industrial pure titanium and chemical pure titanium is that it contains more oxygen,nitrogen,carbon,and various other elements(such as iron,silicon,etc.),and it is essentially a low alloy content titanium alloy.Compared with chemically pure titanium,its strength is greatly improved due to the presence of more elemental impurities,and its mechanical and chemical properties are similar to those of stainless steel(although compared to titanium alloys,its strength is still lower).

The characteristics of industrial pure titanium are:low strength,good plasticity,easy processing into rows,good stamping,welding,and cutting processing performance;It has good corrosion resistance in the atmosphere,seawater,wet chlorine gas,and oxidizing,neutral,and weakly reducing media.Its oxidation resistance is better than that of most austenitic stainless steels,but its heat resistance is poor and the operating temperature is not too high.

Industrial pure titanium is divided into three grades based on its impurity content:TA1,TA2,and TA3.The interstitial impurity elements of these three industrial pure titanium gradually increase,so their mechanical strength and hardness also gradually increase,but their plasticity and toughness decrease accordingly.

The commonly used pure titanium in industry is TA2,due to its moderate corrosion resistance and comprehensive mechanical properties.TA3 can be used when high requirements are placed on corrosion resistance and strength.TA1 can be used for better molding performance requirements.

αType titanium alloy:

This type of alloy hasαThe single-phase state cannot be strengthened by heat treatment(quenching is the only treatment method),and mainly relies on solid solution strengthening.Room temperature strength is generally lower thanβType andα+βType titanium alloys(but higher than industrial pure titanium)have the highest strength and deformation among the three types of titanium alloys at high temperatures(500℃-600℃),with stable microstructure,good oxidation resistance and welding performance,good corrosion resistance and machinability,but low plasticity(still good thermoplasticity)and poor room temperature stamping performance.The most widely used among them is TA7,which has moderate strength and sufficient plasticity in the annealed state,good welding performance,and can be used below 500℃.When its interstitial impurity elements(oxygen,hydrogen,nitrogen,etc.)are extremely low,it also has good toughness and comprehensive mechanical properties at ultra-low temperatures,making it one of the excellent ultra-low temperature alloys.

βType titanium alloy:

The main alloying elements of this type of alloy are molybdenum,chromium,vanadium,etcβStable elements.It is easy to cause high temperatures during normalizing or gradingβRetain at room temperature to obtain metastableβSingle phase organization,hence the nameβType titanium alloy.

βType titanium alloy can be heat treated and strengthened,with high strength,good welding performance and pressure processing performance;But the performance is not stable enough and the smelting process is complex,so the application is not as good asαTypeα+βTitanium alloys are widely used.

α+βType titanium alloy:

This type of alloy operates at high temperaturesα+βA type of two-phase organization,hence the nameα+βType titanium alloy.It has good comprehensive mechanical properties and can mostly be strengthened by heat treatment(but TC1,TC2,and TC7 cannot be strengthened by heat treatment).It has good forging,stamping,and welding performance,can be machined,and has high room temperature strength.Below 150-500 degrees and with good heat resistance,some(such as TC1,TC2,TC3,TC4)also have good low-temperature toughness and resistance to seawater stress corrosion and hot salt stress corrosion.The disadvantage is that it is not stable enough.

TC4 is the most widely used alloy of this type,accounting for about half of the current production of titanium alloys.This alloy not only has good mechanical properties at room temperature,high temperature,and low temperature,but also has excellent corrosion resistance in various media.It can be welded,cold and hot formed,and heat treated for strengthening;Therefore,it has been widely used in industries such as aerospace,shipbuilding,weapons,and chemical industry.