Medical titanium rod The manufacturer introduces that the reaction of titanium alloy materials such as titanium rod and tube in air usually reacts with non-metallic elements such as oxygen, nitrogen and hydrogen. The reaction process is closely related to temperature.

Titanium reacts very slowly with oxygen below 100 degrees in the air, and only the surface will be oxidized at 500 degrees. As the temperature rises, the oxide film on the surface begins to dissolve, and oxygen begins to diffuse into the metal. However, at 700 ℃, oxygen does not enter the inner lattice of the metal. When the temperature is above 700 ℃, the diffusion of oxygen to metal accelerates, and the surface oxide film loses its protection at high temperature.

The reaction of titanium to oxygen depends on the shape and temperature of titanium. Powdered titanium powder will burn or explode violently under the action of electrostatic spark and friction in the air at room temperature. However, titanium is stable in air at room temperature. After being heated in air, the dense titanium begins to react with oxygen. 1、 Oxygen enters the titanium surface through the lattice to form a dense oxide film. The surface of the oxide film can prevent the oxygen from diffusing inward and play a protective role. As a result, titanium remained stable in air below 500 ℃. The color of surface oxide film is related to formation temperature.

Below 200 degrees is silver white, 300 degrees is light yellow, 400 degrees is golden yellow, blue is 500 degrees, 600 degrees is purple, 700-800 degrees is red gray, 800-900 degrees is gray. Under pure oxygen condition, the initial temperature ratio of titanium to oxygen is lower than that in air. Titanium burns in oxygen at about 500-600 ℃. Titanium does not react with nitrogen at room temperature, but it is one of the few metal elements that can burn in nitrogen at high temperature. When the combustion temperature of titanium in nitrogen exceeds 800 ℃, the reaction between titanium and nitrogen is very strong. Titanium reacts with nitrogen to form not only titanium (ti3n, TiN), but also Ti-N solid solution. At 500~550 ℃, titanium begins to absorb nitrogen and form interstitial solid solution; When the temperature exceeds 600 ℃, the nitrogen absorption rate of titanium increases. Nitrogen in the Ti-N solid solution enters the titanium lattice in the form of titanium nitride, and the phase transition temperature of titanium increases. Nitrogen is also a stabilizer of titanium. The solubility (mass fraction) of nitrogen in air is 7% at 1050 ℃ and 2% at 2020 ℃. However, the absorption of nitrogen by titanium is much slower than that of oxygen. Therefore, titanium mainly absorbs oxygen in the air, while nitrogen absorption is secondary.

The content of this article comes from the network. If you have any questions, please contact me to delete it!