I recommend 150 mL of acetic acid, 37,5 mL of sulfuric acid and 62.5 mL of HF, this solution is very useful to electropolish, and if you only want chemical etching use 55 mL of HNO3, 7.5 mL of HF and 38 mL of deionized water
As chemical etching effectively chemically corrodes metal, titanium’s corrosion resistance presents numerous challenges. Hydrofluoric acid (HF) has been used since to 1960s to etch glass, silicon, and titanium and is usually combined with another chemical to produce an etching or surface treatment solution.
The titanium etching process
Titanium etching works much like traditional chemical etching, the process steps summarised as follows:
Sheet titanium is cleaned then laminated with photoresist (a light-sensitive polymer)
The photoresist is exposed to UV-light, which transfers the CAD image of the component
Areas of unexposed resist are removed (developed) to reveal the raw titanium
The sheet is sprayed with hydrofluoric acid, selectively removing the unprotected titanium
The remaining photoresist is removed (stripped) to reveal the final etched component
Effect of HF on titanium
HF acid treatment of Ti surfaces modifies their chemical composition, which becomes stable after 3 min. of etching.Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time.
Alternative etching for Titanium
Electrolytic etching involves the use of a solution of an electrolyte, an anode, and a cathode to selectively remove the titanium by reverse plating.
While electrolytic etching is cheaper to set up and uses chemicals broadly classified as “safe” to use, the process is difficult to serialise as only smaller sheets can be used, and there is more chance of process variation which affects repeatability.
As chemical etching effectively chemically corrodes metal, titanium’s corrosion resistance presents numerous challenges. Hydrofluoric acid (HF) has been used since to 1960s to etch glass, silicon, and titanium and is usually combined with another chemical to produce an etching or surface treatment solution.
The titanium etching process
Titanium etching works much like traditional chemical etching, the process steps summarised as follows:
Sheet titanium is cleaned then laminated with photoresist (a light-sensitive polymer)
The photoresist is exposed to UV-light, which transfers the CAD image of the component
Areas of unexposed resist are removed (developed) to reveal the raw titanium
The sheet is sprayed with hydrofluoric acid, selectively removing the unprotected titanium
The remaining photoresist is removed (stripped) to reveal the final etched component
Effect of HF on titanium
HF acid treatment of Ti surfaces modifies their chemical composition, which becomes stable after 3 min. of etching.Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time.
Alternative etching for Titanium
Electrolytic etching involves the use of a solution of an electrolyte, an anode, and a cathode to selectively remove the titanium by reverse plating.While electrolytic etching is cheaper to set up and uses chemicals broadly classified as “safe” to use, the process is difficult to serialise as only smaller sheets can be used, and there is more chance of process variation which affects repeatability.