Anodic Dissolution of Gamma Titanium Aluminide GE 48-2-2, TNM B1 and TNB V5 Materials using Electrochemical Machining Electrolytes for Aviation Application

Investigation of temperature resistant lightweight materials used in airplane components with higher thermal efficiency gaining importance. These materials possess challenges and replace twice dense nickel (Ni) based super alloys presently found application in aeroplane industry. In this article, anodic dissolution of commercial gamma titanium aluminide (γ-TiAl) alloys; GE 48-2-2, TNM B1 and TNB V5 were investigated. These are potential materials to be used for manufacturing low pressure turbine blades by electrochemical machining. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD confirms the presence of two phases Ti3Al, α2(13.8%) and TiAl, γ (86.2%). SEM shows the porous surface after the anodic dissolution. It has been found that 1 M KBr is the most effective electrolyte for the dissolutionfollowed by NaCl and NaNO3. The effect of temperature, electrolyte concentration, passivation and rotation speed were evaluated. The dissolution potential of TNB V5 found to be high could be due to the presence carbon content which may lead to the high creep resistance in the material.