Preparation And Properties For Al₂tio₅-aln-al Composite Material

Aluminium titanate's melting point is 1860℃, thermal expansion coefficient is less than 2.0×10-6/℃, has excellent thermal shock resistant, resistant of molten steel and clinker erosion, but it has lower mechanical robustness. Aluminium nitride's thermal conductivity is 320W/(m·K), thermal expansion coefficient is 4.6×10-6/℃. Aluminium has good thermal conductivity 237W/(m·K), and the characteristic of high temperature plasticity. Importing aluminium nitride and aluminium into aluminium titanate is expected to improve aluminium titanate's mechanical robustness and thermal shock resistant.Aluminium titanate, aluminium and aluminium nitride were used as the raw material, after molded by pressing the samples sintered at 1200℃×2h, 1300℃×2h and 1400℃×2h to prepare aluminium titanate-aluminium nitride-aluminium composite material. Effect of the addition of aluminium, grain size of aluminium titanate, sintering temperature and complex methods to sintering performance, fine texture, phase composition, thermal expansibility and thermal shock resistant was studied.The research indicated: the samples which added 20wt.% aluminium, its modulus of rupture is higher 34.65% than the parallel sample without aluminium, and its remained thermal shock resistant is higher than other aluminium contents composite materials, but it has high thermal expansion coefficient which from 25℃to 1100℃is 5.49×10-6/℃; the composite material sintered at 1400℃has excellent modulus of rupture and remained thermal shock resistant, and its thermal expansion rate is lower than the samples sintered at 1200℃and 1300℃; when the grain size of aluminium titanate is less than 48μm, sample's inner particles are able to accumulate closely, composite material has compact structure, and its modulus of rupture and remained thermal resistant are better than other grain size samples; AT-AlN composite material which thermal expansion coefficient from 25℃to 1100℃is 3.81×10-6/℃, its modulus of resistant and remained thermal resistant are better than the parallel sample without aluminium.