Electrochemical Discharge Machining (ECDM) Glass Calculator

4. Engineering Notes & Physics Specifications

Electrochemical Discharge Machining (ECDM / SACE) Physics: ECDM enables non-contact micro-machining of non-conductive brittle materials like borosilicate glass and fused quartz. When the cathodic DC cell voltage exceeds critical voltage $V_c$, high-density hydrogen gas bubbles coalesce into a continuous insulating vapor sheath around the micro-tool. Spark discharges across this dielectric gas envelope deliver localized thermal shocks ($> 1000^\circ\text{C}$) combined with accelerated chemical etching by concentrated hydroxide ions ($OH^-$).

Radial Overcut & Vector Offset: The effective channel width $W_{channel}$ is: $$W_{channel} = D_{tool} + 2 \cdot \Delta R$$ where radial overcut $\Delta R = h_{film} + S_{discharge}$. Programmed vector toolpaths must apply inward tool radius compensation: $R_{prog} = (W_{target} - 2\Delta R)/2$.