Alloying treatment of the surface of titanium tube

After plating palladium on titanium tube, it can be heated by different methods to make the plating layer spread to the surface layer of titanium tube, and form the surface layer of titanium and palladium alloy layer, which can improve the corrosion resistance. Heat diffusion or laser surface remelting are feasible in principle. Using a laser to illuminate the titanium surface to make it quickly melted and condensed, can make the 150 microns of palladium plated film of pre vacuum deposition quickly melt and form palladium alloy. On the surface, the mole fraction of palladium is only 4%. Putting the titanium alloy with the alloying surface into hydrochloric acid solution, three hours later, the mole fraction of palladium can reach 15%. Some people use the method of ion implantation to achieve the palladium alloy of titanium surface.

The palladium alloying of the surface of titanium tube can also be called as a kind of coating, which has the advantages of good bonding strength, wear resistance and corrosion resistance compared with the oxide coating on titanium. Compared with the titanium palladium alloy, the surface content of palladium is high, which saves precious metal palladium, reduces the cost, and has excellent performance. The surface penetration of titanium tube can reduce the hydrogen absorption tendency of titanium. The best alumetizing condition is that make 88% of the aluminum oxide, 4% aluminum fluoride and 8% aluminum powder be mixed and coated on the titanium workpiece, the temperature is 810 degrees. The thickness and the structure of the aluminum layer are dependent on the holding time. Using the infiltration process of aluminum, the short time diffusion can get about 2 mm thick thin coating, which has good bonding strength and does not affect the mechanical properties of the matrix. The coating is mainly composed of titanium oxide phase to form a barrier layer, which is very effective in preventing hydrogen permeation.