Experimental Investigation on the Performance of Grinding Assisted Electrochemical Discharge Drilling of Glass

At a Glance

Metadata	Details
Publication Date	2016-01-01
Journal	MATEC Web of Conferences
Authors	V. G. Ladeesh, R. Manu
Institutions	National Institute of Technology Calicut
Citations	4
Analysis	Full AI Review Included

Technical Documentation & Analysis: Grinding Assisted Electrochemical Discharge Drilling (G-ECDD)

Source Paper: Ladeesh V G, Manu R, Experimental Investigation on the Performance of Grinding Assisted Electrochemical Discharge Drilling of Glass (MATEC Web of Conferences 51, 003001, 2016).

Executive Summary

This analysis focuses on the material requirements and process optimization for Grinding Assisted Electrochemical Discharge Drilling (G-ECDD), a hybrid technique utilizing diamond tooling for machining brittle materials like glass and advanced ceramics.

Application: Efficient and economical production of micro and macro holes in non-conductive brittle materials (e.g., glass, Al₂O₃).
Mechanism: Material removal is achieved through a synergistic combination of thermal melting (electric discharge), mechanical grinding (diamond grits), and chemical etching.
Key Process Drivers: Duty cycle and voltage were identified as the most significant factors influencing Material Removed (MR).
Optimal Performance: Highest MR (0.1032g) was achieved using high voltage (105V), high duty cycle (0.7), low cycle time (0.00065s), and high electrolyte concentration (3.5M KOH).
Tool Life Challenge: Significant tool wear was observed at the end face of the diamond core drill, particularly at high frequencies (>5kHz) and high voltage (110V).
Material Solution: The research explicitly recommends increasing the thickness of the diamond coating layer at the end face to mitigate wear and significantly extend tool life, a direct requirement met by 6CCVD’s custom MPCVD capabilities.

Technical Specifications

The following hard data points were extracted from the experimental setup and results:

Parameter	Value	Unit	Context
Workpiece Material	Sodalime Glass	N/A	Brittle, non-conductive material
Electrolyte	Potassium Hydroxide (KOH)	N/A	Concentration range 2M to 4M
Electrolyte Temperature	40	°C	Maintained for consistent reaction kinetics
Voltage (A) Range	90 to 110	V	Pulsed DC supply
Duty Cycle (B) Range	0.4 to 0.8	N/A	Most significant factor for MR
Cycle Time (C) Range	0.0002 to 0.002	s	Corresponds to sparking frequency (500 Hz to 5 kHz)
Max Material Removed (MR)	0.1032	g	Achieved at 105V, 0.7 DC, 0.00065s, 3.5M
Optimal Tool Wear Reduction	80V, 500Hz	V, Hz	Low voltage and low frequency minimize wear
Tool Wear Location	End face	N/A	Wear at the end face is predominant
Machined Hole Diameter	6	mm	Example hole size demonstrated
Model Fit (R²)	89.78	%	Coefficient of multiple determination for MR model

Key Methodologies

The G-ECDD process relies on precise control of electrical, chemical, and mechanical inputs, requiring specialized diamond tooling.

Experimental Setup: Experiments were conducted using a modified CNC Router (Newclear TR 203) equipped with a customized pulsed DC power supply capable of varying duty cycle and frequency.
Tooling System: A spring-fed tool arrangement was designed and fabricated to ensure smooth, balanced feed, preventing the mechanical grinding action of the diamond grits from predominating over the electrochemical discharge.
Tool Material: A rotating diamond core drill (diamond coated/impregnated) was used as the cathode, with a steel plate serving as the anode.
Process Parameters: Four primary factors were systematically investigated using Central Composite Rotatable Design (CCRD): Voltage, Duty Cycle, Cycle Time, and Electrolyte Concentration.
Material Removal Mechanism: Pulsed DC voltage generates hydrogen bubbles at the cathode, forming a gas film at a critical voltage. This leads to high current density, ionization, and electric arc strikes, causing thermal melting, which is then removed by the rotating diamond grits.
Measurement: Material Removed (MR) and Tool Wear were determined gravimetrically by measuring the weight difference of the workpiece and the tool, respectively, before and after a 2-minute machining duration.

6CCVD Solutions & Capabilities

The research highlights a critical need for high-quality, custom-engineered diamond tooling, specifically focusing on maximizing the thickness and integrity of the diamond layer at high-wear zones. 6CCVD is uniquely positioned to supply the advanced MPCVD diamond materials required to replicate and extend this high-performance G-ECDD research.

Applicable Materials

To achieve the high wear resistance and structural integrity required for G-ECDD tools, 6CCVD recommends the following materials:

High-Purity Polycrystalline Diamond (PCD): Ideal for the core drill structure due to its exceptional hardness, thermal stability, and ability to be fabricated into large, robust wafers (up to 125mm). PCD provides the necessary mechanical strength for the grinding component of the hybrid process.
Thick Single Crystal Diamond (SCD) Layers: For applications requiring extremely high thermal conductivity or specific crystallographic orientation, 6CCVD can provide SCD material up to 500µm thick, suitable for use as a coating or insert material in the high-wear end face zone.
Boron-Doped Diamond (BDD): While not used in this specific study, BDD is available for future G-ECDD research involving conductive workpieces or where enhanced electrochemical stability is required.

Customization Potential

The paper’s conclusion—that increasing the thickness of the diamond coating layer at the end face is essential for tool life—is a direct match for 6CCVD’s core capabilities.

Research Requirement	6CCVD Custom Solution	Technical Specification
Thick Diamond Layer	Custom thickness control for high-wear zones.	SCD/PCD thickness up to 500µm.
Core Drill Fabrication	Supply of large-area PCD wafers for tool blanks.	Plates/wafers up to 125mm (PCD).
Custom Geometry	Precision laser cutting and shaping services.	Custom dimensions and geometries for core drill tips.
Metalization (Future Work)	Internal metalization services for bonding/mounting.	Au, Pt, Pd, Ti, W, Cu metalization available.
Surface Finish	Ultra-low roughness for optimal material interaction.	Polishing capability: Ra < 5nm (Inch-size PCD).

Engineering Support

6CCVD’s in-house team of PhD material scientists specializes in optimizing diamond properties for extreme applications.

Process Optimization: We offer consultation on selecting the optimal diamond grain size and morphology (PCD) to balance the mechanical grinding action with the electrical discharge requirements of G-ECDD.
Wear Mitigation: Our experts can assist researchers in designing diamond tool inserts or coatings that maximize thickness and adhesion specifically at the high-stress end face, directly addressing the tool wear problem identified in this study.
Global Logistics: We ensure reliable, global shipping (DDU default, DDP available) of custom diamond materials to support international research efforts.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

\nGrinding assisted electrochemical discharge drilling (G-ECDD) is a novel technique for producing micro and macro holes in brittle materials including advanced ceramics and glass, both efficiently and economically. G-ECDD involves the use of a rotating diamond core drill as the tool in a normal electrochemical discharge machine setup. The material removal happens by a combination of thermal melting due to electric discharges, followed by grinding action of diamond grits and chemical etching action. In this study, the effect of process parameters like voltage, duty cycle, cycle time and electrolyte concentration on material removed (MR) was investigated systematically using response surface methodology. Analysis of variance was performed to identify the significant factors and their percentage contribution. The most significant factor was found to be duty cycle followed by voltage, cycle time and concentration. A quadratic mathematical model was developed to predict MR. Tool wear was found for different frequencies and voltages. Higher tool wear was observed for high frequency above 5kHz pulsed DC supply at high voltage of 110V. Tool wear at the end face of the tool was found to be a significant problem affecting the tool life.\n

Tech Support

Original Source

DOI: https://doi.org/10.1051/matecconf/20165103001