Ultrasonic vibration-assisted arc machining of Inconel 718: Achieving concurrent processing efficiency enhancement...

Area of Science:

• Materials Science and Engineering
• Manufacturing Processes
• Surface Engineering

Background:

• Conventional arc discharge machining (EAM) faces a conflict between processing efficiency and surface integrity due to thermal instability.
• Advanced materials require high-integrity manufacturing, which is hindered by the limitations of existing machining technologies.
• Ultrasonic vibration-assisted machining shows promise for improving processing performance.

Purpose of the Study:

• To introduce a novel ultrasonic-arc composite machining (UEAM) paradigm.
• To achieve coordinated regulation of the energy-precision paradox in machining.
• To enhance the manufacturing of advanced materials under extreme conditions.

Main Methods:

• Pulse discharge tests combined with in-situ high-speed photography to analyze plasma channel dynamics in UEAM and EAM.
• Continuous milling discharge tests to verify the processing performance of UEAM.
• X-ray Diffraction (XRD) phase analysis to assess the recast layer composition.

Main Results:

• Ultrasonic vibration reduced plasma breakdown delay by 84.6% and increased discharge frequency by 150%.
• UEAM reduced carbon and oxygen enrichment in the recast layer by 31.36% and 70.73%, respectively, restoring Nickel content to 40.89%.
• Recast layer thickness was reduced by 74.8%, and the formation of brittle phases was significantly inhibited.

Conclusions:

• UEAM provides a general solution for high-precision, low-damage machining of high-temperature alloys.
• The technology achieves coordinated enhancement of element distribution homogeneity and surface integrity.
• A three-level synergistic mechanism involving plasma dispersion, melt pool mass transfer, and solidification control is proposed.