SURFACE ROUGHNESS CHANGE IN THE HEAT TREATMENT OF Ti-6Al-4V EXTRA LOW INTERSTITIAL ALLOY

The heat treatment improves the casting results structure and changes the alloys microstructure. The fractal dimension of the Ti-6Al-4V Extra Low Interstitial (ELI) alloy changes with the alteration of surface roughness under various heat treatment conditions. This study used three primary raw materials: first-grade Titanium, pure aluminum, and pure vanadium. The SEM images of the sample were translated into topographic data. The Fractal Dimension (FD) calculation results that the surfaces topography appearing throughout the heat treatment temperatures and has fractal features. The Heat Treatment (HT) process shows a close relationship between heat treatment temperature and fractal dimension. Surface roughness after heat treatment at 1050^oC is smoother than at 850^oC and 950^oC.