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Zirconium diboride (ZrB2) is difficult to prepare as high-density ceramics, which limits its application. To obtain high-density ZrB2 ceramics for improving its high-temperature properties, ZrB2 particles were coated with Al2O3--Y2O3 particles to prepare 20% YAG--ZrB2 ceramics with SPS. The optimum sintering condition is a temperature of 1700°C, a pressure of 20 MPa, and a holding time of 4 min. The relative density of prepared 20% YAG--ZrB2 multi-phase ceramics is 97.2% under optimization sintering technology, which indicate that high density YAG--ZrB2 multi-phase ceramics are successfully prepared. [ABSTRACT FROM AUTHOR]

Zirconium diboride is widely applied to high-temperature materials, but it is easily oxidized at high temperature. To increase the oxidation resistance of zirconium diboride at high temperature, the A1(OH)3–Y(OH)3 is coated on the ZrB2 surface to prepare A1(OH)3–Y(OH)3/ZrB2 composite particles. In this paper, the effect of coating content on the properties of A1(OH)3–Y(OH)3/ZrB2 composite particles is investigated. It is analyzed that the particle size and particle size distribution of A1(OH)3–Y(OH)3/ZrB2 composite particles is increased with the coating content. The dispersion of ZrB2 particles is largely increased with the coating content of 0%–20%; the dispersion of ZrB2 particles is similar when the coating content is from 20% to 30%. The oxidation resistance ratio of the ZrB2 particles with 30% coating content is the best than that of other conditions—it is about three times more than that of the original ZrB2 particles. [ABSTRACT FROM AUTHOR]

In order to decrease the oxidization and improve the strength of ZrB2 at high temperature, the surface of ZrB2 was coated with Al(OH)3 and Y(OH)3 to synthesize Al(OH)3-Y(OH)3-ZrB2 composite particles. Through TEM, EPMA and SEM analysis, when pH was about 9, Al(OH)3-Y(OH)3-ZrB2 composite particles were successfully synthesized by co-precipitation methods. The coating layer was about 25nm, which has compaction and conformability. Dispersibility of coated ZrB2 with Al(OH)3 and Y(OH)3 particles were very good. Synthesis of Al(OH)3-Y(OH)3-ZrB2 composite powder will lay the foundation for preparing high-performance YAG/ZrB2 and Al2O 3-YAG/ZrB2 multiphase ceramic materials. [ABSTRACT FROM AUTHOR]