Increasing the technological deformability of titanium alloy during rolling using electric current pulses

The low thermal conductivity of a titanium alloy significantly affects its deformation characteristics, reducing plasticity and making it difficult to uniformly deform the blank, and during cold rolling leads to the formation of cracks in the strips. The effect of electric current pulses introduced into the deformation zone on the deformability of the rolled titanium alloy VT6 has been studied. Rolling was carried out without intermediate annealing. It was found that the use of current pulses increases the deformation by more than 3.5 times. At the same time, microscopic cracks and ruptures do not form. To explain the obtained results on model samples using high frequency accelerometers mounted on them, fast-flowing processes in titanium caused by current pulses were studied. The acceleration of the material surface layers was determined. The amount of current through the sample was controlled by a non-contact sensor. The signals from the sensors were processed on a computer. It was found that the action of current pulses on titanium leads to a mechanical shock response in the metal, which turns into damped vibrations propagating in it in the form of vibroacoustic waves. Shock responses were formed on the leading and trailing edges of the electric pulse in opposite directions. The shock response can be explained by the short-term action of the longitudinal Ampere force in the metal, which arises from the interaction of the emerging radial currents and the intrinsic magnetic field of the current. The amplitude of the metal response linearly depended on the amplitude of the electric pulse and its direction. The response is not caused by the thermal action of the current or the pinch effect. The effect of an electric pulse on metal is in many ways similar tothe effect of ultrasound. The obtained results can be applied in the development of technology for manufacturing thin strips of titanium alloys by pressure.