La2Zr2O7 （LZ） is a promising thermal barrier coating material for the high temperature applications. The fracture toughness and microhardness of nanocrystalline LZ （n-LZ）, microcrystalline LZ （m-LZ） and LZ-5mol%...La2Zr2O7 （LZ） is a promising thermal barrier coating material for the high temperature applications. The fracture toughness and microhardness of nanocrystalline LZ （n-LZ）, microcrystalline LZ （m-LZ） and LZ-5mol%8YSZ （LZ-5-8YSZ） composite （8YSZ for zirconia stabilized by 8 mol% ytrria） were studied. The n-LZ had a thermal expansion coefficient of （9.6±0.4）×10 -6 K -1 （200～1000℃） and fracture toughness of （1.98±0.07） MPa·m 1/2 which are obviously higher than those of the m-LZ （ （9.1±0.4）×10 -6 K -1 and （1.40±0.23） MPa·m 1/2, respectively）, indicating that nanofication was an efficient way to increase the toughness and thermal expansion coefficient of LZ. The composite LZ-5-8YSZ had a higher fracture toughness （（1.88±0.30） MPa·m 1/2） than LZ, which was close to that of 8YSZ densified by superhigh pressure （SHP）.展开更多
文摘La2Zr2O7 （LZ） is a promising thermal barrier coating material for the high temperature applications. The fracture toughness and microhardness of nanocrystalline LZ （n-LZ）, microcrystalline LZ （m-LZ） and LZ-5mol%8YSZ （LZ-5-8YSZ） composite （8YSZ for zirconia stabilized by 8 mol% ytrria） were studied. The n-LZ had a thermal expansion coefficient of （9.6±0.4）×10 -6 K -1 （200～1000℃） and fracture toughness of （1.98±0.07） MPa·m 1/2 which are obviously higher than those of the m-LZ （ （9.1±0.4）×10 -6 K -1 and （1.40±0.23） MPa·m 1/2, respectively）, indicating that nanofication was an efficient way to increase the toughness and thermal expansion coefficient of LZ. The composite LZ-5-8YSZ had a higher fracture toughness （（1.88±0.30） MPa·m 1/2） than LZ, which was close to that of 8YSZ densified by superhigh pressure （SHP）.
