Abstract: Ultrafine diamond abrasive tools have been made by sol-gel technique. Shear dispersing is proposed to resolve the uneven distribution of abrasives in the gel bond. Multiple drying control chemical additives are used to improve the property of the bond matrix. And coupling agent is added to enhance the pullout strength of the abrasives from the bond. The results show that ultrafine diamond abrasives distributed uniformly in the gel bond after the shear dispersion. The modified matrix of the tool with compound additives is successfully restrained from shrinkage and prevented from dehydration failure. And the holding force of the abrasives in the matrix is effectively enlarged by chemical bond after adding the coupling agent, avoiding the loss of the abrasives. When lapping and polishing two kinds of typical hard and brittle substrates with this gel-bonded ultrafine diamond tool, an ultra-smooth and scratch-free surface with nanoscale even sub-nanoscale precision can be obtained.

Key words: gel bond, lapping and polishing, substrate, ultrafine diamond