Enhancing Precision in Drilling: Insights from IIT Bombay’s Ultrasonic Study

Mumbai, Researchers at the Indian Institute of Technology Bombay have discovered that Ultrasonic-Assisted Electrochemical Discharge Machining (UA-ECDM) can significantly reduce debris accumulation during micro hole drilling. This advancement notably improves the precision and quality of fabricating brittle materials.

As demand for materials like glass and ceramics grows, their applications in household products, smartphone screens, and advanced medical devices increase. Drilling fine holes in these brittle materials, often as thin as a hair strand, necessitates exceptional precision to prevent cracks, underscoring the importance of innovation in machining techniques.

Recent studies indicate that UA-ECDM, which integrates tiny electric sparks with ultrasonic vibrations, achieves high precision drilling. However, the reasons behind this enhanced efficiency had remained unclear until now.

A new study led by Anurag Shanu and Professor Pradeep Dixit from IIT Bombay addresses this gap in knowledge. Professor Dixit stated, "Earlier studies mainly focused on experimental results, such as machining depth, without explaining the mechanism behind performance improvements through ultrasonic vibration. By analyzing electrolyte flow and debris dynamics, we identified the fundamental mechanisms and the impact of vibration amplitude on debris removal efficiency."

Electrochemical discharge machining works by generating controlled electrical discharges in an electrolyte solution to remove material. These discharges vaporize micro-portions of glass, but as the holes deepen, debris can restrict the flow of fresh electrolyte, diminishing machining efficiency.

The IIT Bombay study clarifies why UA-ECDM is more effective and demonstrates how optimizing vibration amplitude can further improve results. This technique is crucial for creating deep and precise micro features, such as blind or through-holes and micro-channels, in non-conductive materials including soda-lime glass, borosilicate glass, fused silica, polymer composites, and alumina.

Moreover, the research addresses significant manufacturing challenges by enabling the simultaneous drilling of deeper, multiple holes while reducing tool wear. Although current machining tools are created using wire electric discharge machining, which limits the production of ultra-fine features, the study indicates that the minimum achievable hole size may still depend on tool-tip dimensions even with improved UA-ECDM capabilities.