Measurement and control the quality of WEDM in robotized manufacturing
摘要
Electrical discharge machining is used for machining workpieces for aviation, shipbuilding and other technology fields that use difficult-to-process materials. Wire electrical discharge machining is characterized by instability in both quality and performance. This article proposes the measurement of roughness parameters, estimation using a spectral power density and a fractal dimension, as well as control of wire breakage using an acoustic emission. Heat-resistant nickel-based steel specimens were machined in various modes based on a factorial experiment. Spectral analysis of roughness was carried out based the accumulated spectral power. It was found that the roughness is mainly formed by spatial frequencies up to 0.05 μm-1. The calculation of fractal dimension by area-scale method was performed. It was found that the profiles are fractal-like in the scale range of 20–500 μm, and the pulse current affects both Ra and fractal dimension. The Amplitude Transformation Index of the acoustic emission for wire break control is proposed. The results obtained make it possible to increase the efficiency of quality control of wire electrical discharge machining.