| Abstract |
| Ceramic abrasives are used widely as grinding materials because of their good wear resistance. In particular, alumina abrasives have other excellent mechanical properties, such as toughness, hardness, and durability. Nevertheless, relatively few studies have been carried out domestically in comparison with research in this field that has been conducted abroad. In this study, a fine-grained alumina abrasive that had a dense microstructure with a needle-type second phase, SrAl12O19,was successfully fabricated by impregnating a solution in corporating Sr and Y cations into a porous alumina gel prepared from boehmite sol. The final phase and microstructure as well as the porosity and density of the sintered alumina were dependent on the mixing ratio of Sr and Y nitrates, the concentration of the solution, the sintering temperature, and the heating rate. With a mixing ratio of 1:1 wt% of Sr and Y and above a 10 wt% concentration, a dense and homogeneous microstructure was achieved with needle-type grains with sizes of 1.0-2.0 μm. A denser microstructure with fine grains and improved hardness were obtained by an ultra-fast sintering process at relatively low sintering temperature of about 1400 ℃. (Received April 30, 2013) |
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| Key Words |
| Ceramics, Sintering, Microstructure, Hardness test, Sol-gel method |
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