The difference, connection and application of industrial pure titanium and titanium alloy

The density of titanium is 4.5g/cm3, 57% of that of steel. Titanium is less than twice as heavy and three times as strong as aluminum. The specific strength is the ratio of strength to density. When compared with different materials, the specific strength of titanium alloy is almost the largest in common industrial alloys. The specific strength of titanium alloy is 3.5 times that of stainless steel, 1.3 times that of aluminum alloy and 1.7 times that of magnesium alloy, so it is an essential structural material for aerospace industry. Comparison of density and specific strength of titanium with other metals. Titanium has high melting point, poor thermal conductivity and electrical conductivity, similar to or slightly lower than stainless steel, titanium has superconductivity, the critical superconductivity temperature of pure titanium is 0.38.4K. Titanium is a nonmagnetic substance.

Titanium alloy is a phase solid solution composed of single-phase alloy, low density, whether at general temperature or at higher practical application temperature, are a phase, stable structure, wear resistance is higher than pure titanium, strong oxidation resistance. Under the temperature of 500-600 degrees, it still maintains its strength and creep resistance, can be strengthened by heat treatment, has good thermal strength and thermal stability, good welding performance, has good room temperature, ultra-low temperature and high temperature performance.

Commercial pure Titanium is a dense metal titanium with at least 99% titanium content and a small amount of impurities such as iron, carbon, oxygen, nitrogen, and hydrogen. The impurities that most strongly affect the mechanical properties of pure titanium are oxygen, nitrogen and iron, especially oxygen. The reaction between hydrogen and titanium is reversible, and the effect of hydrogen on the performance of titanium is mainly manifested as "hydrogen embrittledness", which usually stipulates that the hydrogen content should not exceed 0.015%, generally containing 0.15%-0.3% oxygen and 0.03%-0.05% nitrogen. Industrial pure titanium is packed hexagonal lattice at room temperature, but its axis is relatively small (C/A =1.587), has good machinability, pure titanium molding and welding performance is good, is not sensitive to heat treatment. In titanium metals, including titanium plates, titanium rods, titanium tubes and so on, both pure titanium and titanium alloys are included. The significant difference between pure titanium and titanium alloy is that titanium alloy is added on the basis of pure titanium such as Al, Mo, Cr, Sn and other chemicals, and it is because of these chemicals that lead to the difference in the performance of the two titanium metals. The following small series focuses on the analysis of pure titanium in classification, performance and use.

1. Classification of pure titanium:
According to impurity content, titanium can be divided into high purity titanium (99.9% purity) and industrial purity titanium (99.5% purity). There are three grades of industrial pure titanium, respectively represented by TA+ serial number 1, 2, 3, the higher the number, the lower the purity.

2, pure titanium performance:
Ti: 4.507g /cm3, Tm: 1688℃. The α phase with dense hexagonal structure is less than 882.5℃, and the β phase with body centered cubic structure is more than 882.5℃.

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 be burned when heated in nitrogen, so titanium should be protected by argon during heating and welding.

3, pure titanium uses:
Impurity content has a great influence on the performance of titanium, a small amount of impurities can significantly improve the strength of titanium, so the strength of industrial pure titanium is high, close to the level of high strength aluminum alloy, mainly used in the manufacture of petrochemical heat exchangers, reactors, ship parts, aircraft skin and so on.