Physics of loose abrasive microgrinding.

Area of Science:

• Materials Science
• Mechanical Engineering
• Surface Chemistry

Background:

• Microgrinding utilizes micron and submicron abrasives.
• Understanding the brittle-to-ductile transition is crucial for precision manufacturing.
• Loose abrasive grinding processes are sensitive to process parameters.

Purpose of the Study:

• To investigate the physics of loose abrasive microgrinding.
• To determine the influence of slurry chemistry on the brittle-to-ductile transition.
• To quantify surface stress changes during ductile mode grinding.

Main Methods:

• Experimentation with diamond abrasives (3.0-0.75 microm) on ULE and Zerodur substrates.
• Systematic variation of slurry chemistries (water, n-alcohols, various solvents).
• Analysis of material removal modes (brittle vs. ductile) and surface stress (Twyman Effect).

Main Results:

• Ductile mode grinding achieved with smaller abrasives.
• Slurry chemistry dictates the brittle-to-ductile transition point for specific abrasive sizes.
• The observed slurry dependency is primarily attributed to the Rebinder effect.
• Ductile mode grinding significantly increases surface stress (factor of 4 in Twyman Effect on ULE).

Conclusions:

• Slurry chemistry is a critical, controllable factor in loose abrasive microgrinding.
• The Rebinder effect governs the slurry-induced transition between brittle and ductile material removal.
• Significant surface stress is an inherent consequence of ductile mode microgrinding, requiring further investigation.