Preparation Of Ceramic Slider With Big Dimension And High Precision

Alumina ceramic is now widely used for its high strength, high wear-resistance,high temperature resistance and chemical resistance. The recent development of thealumina forming, sintering and granulation were reviewed. Preliminary tests on theceramic connection were taken, and the cure time in a high temperature was studied.A size degradation technology for alumina produced domestically was proposed. Theeffect of binder content, binder kind and the solid loading on the granulation wasstudied. A new technology of granulation with the slurry prepared by gel-casting wasproposed. The forming and sintering property of the powders was tested.The cure time in a high temperature first reduced，then jumped to a muchbigger number and at last decreased again.Ahorizontal stirring mill was used for the size degradation of Al2O3powder. Witha round speed of2000r/min, mass ratio of Al2O3∶H2O=1∶1, PEG2000content of4wt%of the alumina, and a running time of2h, we got finer alumina powder, with anarrow range of particle size, and d(0.5) of0.192um.The results of granulation showed that the particles had not got regular shapewith PVA as binder, and a lot of apple-shaped particles were found. And this had notbeen improved with more PVA. Particles with regularsphere shape were got withPEG as binder, and the shape and the size of the particles can be improved by theincreasing of the solid loading.Granulation with slurry prepared by gel-casting had got very regular sphericalparticles. And what is more, when the solid loading was increased to50vol%, we gotmore regular particles which had a smooth surface.The packing density and the liquidity of the powders were measured, and theresult showed that the gel-casting granulation powder has the highest packing densityand the best liquidity. And the sintering of the powders showed that size degradationhas an obvious effect on the sintering temperature of alumina.