Production of alumina micro abrasives coated with nano-silica for bonding improvements to zirconia

• Main Authors: Zhang Wei, Ahmad Farooq, Wu Wangping, Kong Dejun
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2018-01-01
• Series: Journal of Experimental Nanoscience
• Subjects: Alumina abrasive; coating; resin bond strength; silicon nanoparticles
• Online Access: http://dx.doi.org/10.1080/17458080.2018.1502478

Tribochemical silica coating is a common practice to achieve suitable adhesion with intended synthetic substrates or natural tissues, and the key to this technology is the preparation of alumina abrasive coated by nano-silica (AACNS). In this paper, a novel physical method of producing silicon nanoparticles (SiNPs) that is the base to AACNS is put forward in this paper. The source of the silica coating is from SiNPs that are produced from spark erosion in deionised water, with an average size distribution between 30 and 50 nm as indicated by SEM analysis. Under optimised mixing conditions, 2 g of purified SiNPs were mixed with 20 g of alumina µ-particles (with an approximate diameter of 100 µm), in the presence of ethanol and stirred thoroughly to form a slurry. The slurry is the then co-fired in an oxidation furnace, initially heated to 120 °C for 20 minutes to evaporate the ethanol, and then re-uploaded again after compaction in a temperature of 1100 °C for 2 hours, after which AACNS are obtained. Afterwards, shear bond strength tests are applied on zirconia ceramic bars, whose surface is modified by AACNS. The result shows that average bond strength is about 12 MPa. This method also could be applied to prepare other kinds of abrasive coated by different nanoparticles for improving the bonding strength between coatings and substrates by the method of tribochemical.