Actual Problems in Machine Building 2018 Vol. 5 No. 3-4

Actual Problems in Machine Building. Vol. 5. N 3-4. 2018 Materials Science in Machine Building ____________________________________________________________________ 112 INFLUENCE OF THE SPECIFIC SURFACE ENERGY OF THE ELECTRON BEAM ON THE THICKNESS OF QUENCHED LAYER OF TITANIUM ALLOY OT4 FORMED BY NON-VACUUM ELECTRON BEAM TREATMENT Ivanov I.V., Ph.D. student, e-mail: i.ivanov@corp.nstu.ru Rudenia E.A., Student , e-mail: katya.rudenya@mail.ru Novosibirsk State Technical University, 20 Prospekt K. Marksa, Novosibirsk, 630073, Russian Federation Abstract Experiments of quenching of the titanium alloy OT4 were carried out by an non-vacuum electron beam. It was found that a primary crystallization processes occurs if specific beam energy is 2.8 kJ/cm 2 . However, melting is occurs and hardened structure is formed if specific beam energy is over than 3.5 kJ/cm 2 . That structure has a high hardness (up to 450 HV), compared to the base material (about 200 HV). The microstructure of the obtained materials was studied by optical metallography. The phase composition was determined by X-ray phase analysis. Keywords electron-beam treatment, quenching, titanium alloys, microhardness