The density of titanium is 4.5g/cm3, which is 57% of that of steel; Titanium is less than twice as heavy and three times stronger than aluminum. Specific strength refers to the ratio of strength to density, and when compared with different materials, the specific strength of titanium alloys is almost the largest among commonly used industrial alloys. The specific strength of titanium alloy is 3 Five times, 1.3 times that of aluminum alloy, and 1.7 times that of magnesium alloy, making it an essential structural material for the aerospace industry. Comparison of density and specific strength between titanium and other metals. Titanium has a high melting point, poor thermal conductivity and conductivity, similar to or slightly lower than stainless steel. Titanium has superconductivity, and the critical superconducting temperature of pure titanium is 0.38.4K. Titanium metal is a non-magnetic substance.

Titanium alloy is The single-phase alloy composed of phase Solid solution has small density. It is a phase both at ordinary temperature and at higher practical application temperature. It has stable structure, higher wear resistance than pure titanium, and strong oxidation resistance. At 500-600 ℃, it still maintains its strength and creep resistance, can be strengthened by heat treatment, and has good thermal strength and stability, good welding performance, good room temperature, ultra-low temperature, and high temperature performance.

Commercial pure titanium is a dense metal titanium with a titanium content of no less than 99% and a small amount of impurities such as iron, carbon, oxygen, nitrogen, and hydrogen. The impurities that have the strongest impact on the mechanical properties of pure titanium are oxygen, nitrogen, and iron, especially oxygen. The reaction between hydrogen and titanium is reversible, and the main effect of hydrogen on the performance of titanium is "hydrogen embrittlement". It is usually specified that the hydrogen content should not exceed 0.015%, generally containing 0.15% -0.3% oxygen and 0.03% -0.05% nitrogen. Although industrial pure titanium has a dense hexagonal lattice at room temperature, its axis ratio is small (c/a=1.587) and has good processability. Pure titanium has good formability and welding performance, and is not sensitive to heat treatment.

In titanium metal, including titanium plates, titanium rods, titanium tubes, and so on, pure titanium and titanium alloys are included. The significant difference between pure titanium and titanium alloys is that titanium alloys add chemicals such as Al, Mo, Cr, Sn, etc. on top of pure titanium, and it is precisely because of these chemicals that these two titanium metals differ in performance. Below, the editor will focus on the analysis and introduction of pure titanium in terms of classification, performance, and use.

1. Classification of pure titanium:

According to the impurity content, titanium is divided into high-purity titanium (with a purity of 99.9%) and industrial pure titanium (with a purity of 99.5%). There are three grades of industrial pure titanium, represented by the TA+sequence numbers 1, 2, and 3. The higher the number, the lower the purity.

2. Performance of pure titanium:

Ti: 4.507 g/cm3, Tm: 1688 ℃. Having an isomorphic transformation, with a dense hexagonal structure at ≤ 882.5 ℃ α Phase, body centered cubic structure at ≥ 882.5 ℃ β Phase.

Pure titanium has low strength, but high specific strength, good plasticity, good low-temperature toughness, and high corrosion resistance. Titanium has good pressure processing performance but poor cutting performance. Titanium can burn when heated in nitrogen, so argon gas should be used for protection during heating and welding.

3. The use of pure titanium:

The impurity content has a significant impact on the performance of titanium, and a small amount of impurities can significantly improve the strength of titanium. Therefore, industrial pure titanium has high strength, close to the level of high-strength aluminum alloy, and is mainly used for manufacturing petrochemical heat exchangers, reactors, ship parts, aircraft skins, etc. working at temperatures below 350 ℃.