ULTRASONIC CNC & BRITTLE CERAMICS

Rotary Ultrasonic Machining (RUM) & Core Drilling Calculator

Calculate acoustic tool acceleration ($a_{\text{max}}$), cutting thrust force reduction percentage, linear diamond grinding speed ($V_c$), and exit breakout offset for Rotary Ultrasonic Machining (RUM) of sapphire, quartz, silicon carbide, and technical ceramics.

1. Input Parameters

Ultrasonic Transducer Frequency (f) [kHz]

Standard resonant frequency (typically 20 kHz or 40 kHz).

Vibration Amplitude (A_pk-pk) [µm]

Peak-to-peak longitudinal acoustic vibration at tool face.

Diamond Core Drill Diameter (D_tool) [mm]

Spindle Rotation Speed (N) [RPM]

Brittle Workpiece Material

2. Calculation Results

Acoustic Acceleration

0.0 g

Force Reduction vs CNC

0.0%

Linear Surface Speed

0.0 m/min

Exit Chipping Offset

0.0 mm

3. Geometric Visualizer

Tooling & Vector Prepress Engineering Notes

1. Acoustic Micro-Hammering Mechanics: In Rotary Ultrasonic Machining (RUM), high-frequency axial oscillation imparts peak accelerations $a_{\text{max}} = 4 \pi^2 f^2 A$ exceeding $15,000\,g$, propagating micro-cracks beneath diamond abrasive grains to remove brittle material via ductile-mode chipping.

2. Cutting Force Reduction: Due to intermittent tool-workpiece separation (duty cycle ~30–50%), thrust force is reduced by 40–65% compared to conventional core drilling, preventing edge breakout and tool glazing.

3. Exit Hole Chamfer Prepress Toolpaths: To prevent brittle exit breakout (shelling), CAM vector toolpaths must program a $0.20–0.40\text{mm}$ bottom deceleration dwell and circular interpolation spiral entry/exit.