Chemical Etching as a Method of Combatting Adhesive Tool Wear During Severe Plastic Deformation of Commercially-Pure Titanium

摘要

This paper investigates chemical etching as a potential temporary solution to severe adhesive wear experienced during forming of commercially-pure titanium. The aim was to identify contributing factors and experimentally quantify their effects on the etching of CP-Ti and Vanadis 23 tool steel. A comprehensive literature review identified a promising etchant solution, containing 6.5% hydrofluoric acid, 2% formic acid and 2% triethanolamine. A full factorial experiment was designed to test the effects of three factors - hydrofluoric acid concentration, temperature, and time - with statistical analysis to interpret and validate the results. The results confirmed that increasing any of the factors tested leads to a significant increase in titanium dissolution, while only temperature and concentration increases led to a significant increase in steel dissolution. Therefore, a 20°C solution of 3.5% hydrofluoric acid and an etching duration of 35 minutes is recommended for removing adhered titanium without significantly affecting the steel.