Titanium alloys are widely used in aerospace, military industry, civil industry and other fields due to their excellent specific strength, corrosion resistance, good high temperature performance and biocompatibility. However, titanium alloys have relatively low surface hardness and insufficient wear resistance, limiting their application in some specific environments. To improve these properties, researchers have developed a variety of surface treatment techniques to enhance the surface properties of titanium alloys.
1. Surface oxidation treatment
enhances the lubricity of the titanium alloy surface by forming an oxide film, which reduces the adhesion phenomenon during the drawing process.
2. Coating
- Graphite Emulsion Coating
Graphite emulsion is applied prior to hot drawing not only to provide lubrication but also to protect the billet surface from oxidation. Requirements for graphite emulsion include a graphite content of 20-25%, a particle size of 1-3 um, and uniform adhesion to the billet surface.
- Salt and Lime Coating
A salt and lime lubricating layer of specific formulation such as 12% Na2SO4, 12% CaO, 0.3% Na3PO4, 0.2% NaCl and residual water is used, supplemented by a mixture of 75% soap powder and 25% sulphur powder as a solid powdered lubricant.
- Fluorophosphate treatment
After cleaning the surface of billet metal by physical means, the solution is dipped to form a modified covering film on the surface, and then a solid lubricant is applied to obtain a low coefficient of friction and high wear resistance lubrication.
3. Metal film plating
A metal film such as copper, chromium, nickel or tin is plated on the surface of the titanium alloy to reduce direct metal contact during the drawing process and thus reduce adhesion.
4. Boronisation
Put the titanium alloy wire into a mixed solution containing KFB4, BaCl2, NH4NO3 and heat it to boiling and then soak it, take it out and then wash and dry it so that a layer of fluoroborate is generated on the surface of the wire. A layer of aluminium disulphide is also applied to the wire surface as a lubricant during cold piering.
5. Chemical conversion treatment
Through chemical conversion treatment in the titanium alloy surface to form a dense chemical conversion film, this film can be used as a lubricant coating, adsorption of lubricants, so that the wire after multiple drawing surface smooth, no adhesion and skid marks.
6. Lubricant Selection
Selection of suitable lubricants, such as industrial soap powder, graphite milk, and soap powder and other materials of the mixture, should be good with the coating of good wettability, thermal stability is better.
7. Laser Surface Treatment
Laser treatment technologies, including laser cladding, laser surface alloying and laser surface quenching, can be used to improve abrasion resistance, corrosion resistance and hardness by changing the microstructure of the surface layer. The advantage of laser treatment is that it can achieve a significant increase in surface properties without changing the properties of the titanium alloy matrix.
8. Micro-arc oxidation
This is a technique of in-situ growth of ceramic film on the surface of titanium alloys, which can form a layer of ceramic film on the surface of titanium alloys with excellent corrosion and wear resistance. The micro-arc oxidation technology is green and environmentally friendly, which is in line with the sustainable development strategy.
9. Ion injection
By injecting elements such as nitrogen, oxygen and carbon into the surface of titanium alloys, the hardness and wear resistance of the surface can be improved. The thickness of the ion injection layer is usually in the nanometer scale, which can significantly improve the surface properties of titanium alloy.
10. Thermal Diffusion
By diffusing alloying elements into the surface of titanium alloys at high temperatures, an alloyed layer is formed, which improves the surface hardness and wear resistance.
We can provide high quality products, good service and competitive price. We have been committed to producing high quality titanium products such as titanium tubes, titanium wires, titanium plates, titanium strips, titanium rods and other titanium products.
Mob:+8615824687445
E-mail: sales@gneesteel.com
Skype: mmkelly1314
Whatsapp/Wechat: +86 15824687445
