Optimizing Rational Modes in the Electrodischarge Machining of Parts Made of VT5 Titanium Alloy Based on Solving the Problem of Phase Material Conversion Boundary Displacement

The paper presents results of theoretical studies of the VT5 titanium alloy machinability by the electrodischarge machining method based on solving the thermal problem of the material phase transformation boundary displacement (Stefan problem). It proposes a method for determining parameters of electrical pulses for the VT5 alloy electrodischarge machining in order to increase the process productivity; recommendations are provided for that purpose. Density of the heat flux and its duration were determined necessary for implementation of the VT5 alloy electrodischarge machining process. Dependences were established of the minimum value of the heat flux pulse duration, when the VT5 alloy electrodischarge machining process was possible, and of maximum value of the heat flux pulse duration ensuring maximum removal of the VT5 alloy from the workpiece in one pulse, on the heat flux density. It is shown that for the maximum productivity of the VT5 alloy electrodischarge machining at the heat flux density used, it is necessary to assign effective duration of such a flux. Dependences of the heat flux effective duration on its density were established. Besides, to assign rational modes of VT5 ally electrodischarge machining, relationships were established and provided between the VT5 alloy machinability curves (dependences of the material penetration depth on the pulse duration) and other materials, including those for which rational modes are currently defined