IIT Bombay study explains how ultrasonic-aided drilling boosts precision

Mumbai, Nov 14 (PTI) Researchers at the Indian Institute of Technology Bombay (IIT Bombay) have found that Ultrasonic-Assisted Electrochemical Discharge Machining (UA-ECDM) can significantly reduce debris buildup during micro hole drilling, thereby improving the precision and quality of fabricating brittle materials.

Demand for materials such as glass and ceramics continues to grow due to their increasing use in household products, smartphone screens, and advanced medical and industrial components.

Drilling fine holes in these brittle materials -- often as thin as a strand of hair -- requires exceptional precision to avoid cracks, making innovation in machining techniques crucial.

Recent studies have shown that UA-ECDM, which combines tiny electric sparks with ultrasonic vibrations, delivers highly effective precision drilling.

However, the reason behind this enhanced efficiency had remained unclear.

A new study by Anurag Shanu and Prof Pradeep Dixit from IIT Bombay fills this knowledge gap.

"Earlier studies focused mainly on experimental results, such as machining depth, but did not explain the mechanism behind the performance improvement through ultrasonic vibration. By analysing electrolyte flow and debris dynamics, we explained the fundamental mechanism and the role of vibration amplitude in boosting debris removal efficiency," said Prof Dixit, Associate Professor in the Department of Mechanical Engineering at IIT Bombay.

Electrochemical discharge machining (ECDM) works by generating controlled electrical discharges in an electrolyte solution to remove material. These discharges act like tiny lightning bolts that vaporise micro-portions of glass. But as holes deepen, debris accumulation restricts the flow of fresh electrolyte, reducing machining efficiency.

The IIT Bombay study explains why UA-ECDM performs better and shows how optimising vibration amplitude can further enhance results. The technique is valuable wherever deep and precise micro features - such as blind or through-holes and micro-channels - are required in nonconducting materials like soda-lime glass, borosilicate glass, fused silica, polymer composites, and alumina.

The research also tackles major manufacturing challenges by enabling the simultaneous drilling of deeper, multiple holes while reducing tool wear.

Although tools used for machining are currently made using wire electric discharge machining (wire-EDM), a process that limits the creation of ultra-fine features, the study notes that even with improved UA-ECDM capabilities, the minimum achievable hole size may still depend on tool-tip dimensions. PTI SM KRK