Research on Machining Characteristics of TC4 Low-Pressure Micro-Arc Milling Contact Equivalent Area Method

This paper takes titanium alloy Ti-6Al-4V(TC4) as the research object, establishes the mathematical model of process characteristic parameters (milling depth, milling width, electrode diameter) and milling area, and reveals the mathematical relationship between each characteristic parameter and milling area. Arc milling experiments were carried out to study the effect of milling area on processing current, processing quality and processing efficiency. The results show that: changes in the characteristic parameters affect the material etching rate, resulting in changes in the arc discharge energy, which in turn affects the thickness of the heat-affected layer and the recast layer; the average peak current, surface roughness value and the thickness of the heat-affected layer are positively correlated with the milling area, while the maximum permissible feed rate is negatively correlated with the milling area; under the condition of DC voltage of 20 V, the milling depth is 3 mm, the milling width is 2 mm, and the spindle speed is 1 000 r/min, the surface quality is the best, the surface roughness value is 29.31 μm, the thickness of heat-affected layer is 88.24μm, and the maximum material removal rate is 4 996.2 mm³/min. It is proved that the analysis of the milling area is more helpful for the subsequent arc milling machining process regulation and optimization.