THE EFFECT OF ELECTRON-BEAM TREATMENT ON THE DEFORMATION BEHAVIOR OF THE EBAM TI-6AL-4V UNDER SCRATCHING

The effect of the continuous electron beam scanning (CEBS) post-treatment on the microstructure, mechanical properties and scratching behavior of the Ti-6Al-4V alloy samples produced by electron beam additive manufacturing was studied experimentally and by using molecular dynamics simulation. It was found that the CEBS post-treatment resulted in the transformation of the microstructure of the samples from the alpha '-martensite into the alpha+ss structure. The evolution of the sample microstructure was shown to provide improved mechanical characteristics as well as enhanced deformation recovery after scratching. A mechanism was proposed based on the results of molecular dynamics simulation, which attributed the improved recovery of the scratch groves after passing the indenter to reversible ss -> a ->ss phase transformations, which occurred in the vanadium alloyed Ti crystallites.