Titanium 6Al-4V Alloy Pickling Process Control

Ti-6Al-4V (and titanium alloy) pickling processes are an important part of the finishing operations required to remove alpha-case, achieve the desired surface appearance, and to ensure other product quality considerations are met, all with minimal hydrogen pickup and uniform removal. Maintaining the pickling rate along with required levels of process constituents (HF, HNO₃ and dissolved metal) is critical in order to achieve the necessary finished product requirements. Examples of a titanium acid pickling process control strategy and results are presented. The process described uses acid bath temperature control, integrated acid analysis, acid dosing, acid circulation, acid filtration and acid purification, in order to maintain values within set limits and to achieve desired pickling rates (removals) while ensuring other additional customer requirements are met