Establishment of microstructure prediction model for ultrasonic vibration machining of tungsten heavy alloy based on continuum mechanics

Ultrasonic vibration-assisted machining (UVAM) is key to ultra-precision machining of tungsten heavy alloys. Revealing the microstructure evolution mechanism of tungsten heavy alloys under ultrasonic vibration is crucial for enhancing ion impact resistance. This study acquired the stress–strain curves of tungsten heavy alloys via Split Hopkinson Pressure Bar tests and determined the parameters of microstructural evolution equation. Subsequently, the established FE model for ultrasonic assisted scratching (UAS) was calibrated, and a microstructure prediction model based on continuum mechanics was formulated. The accuracy of this microstructure prediction model was validated through UAS experiments, achieving dislocation density prediction accuracy of 97.3% and grain size prediction accuracy of 92.6%. Finally, the microstructure prediction model was implemented into the precise control of the microstructure in UVAM tungsten heavy alloys. This methodology not only circumvents the need for extensive machining trials and costly material characterization but also provides a theoretical underpinning for the optimization of UVAM process for ion impact resistance.