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4695 |
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Tuesday, May 10, 2016, Room 3C + 3D 10:50 AM Ceramic Coatings I |
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Synthesis and thermophysical properties of Gd2Zr2O7/SrZrO3 composite as a thermal barrier coating material |
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Wen Ma* / School of Materials Science and Engineering, Inner Mongolia University of Technology, China Lili Cai / Inner Mongolia University of Technology, China Hongying Dong/ Inner Mongolia University of Technology, China Yu Bai/ Inner Mongolia University of Technology, China Yichuan Yin/ Inner Mongolia University of Technology, China Xinhui Li/ Inner Mongolia University of Technology, China |
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The (GdxSr1-x)ZrO3+0.5x composite (x=0.3, G3S7; x=0.5, G5S5; x=0.7, G7S3) powders and bulk materials were in-situ synthesized by co-precipitation method and sintered by both pressureless sintering (PS) and spark plasma sintering (SPS), respectively. The phase stability of the composite powders and bulk materials were evaluated. The mechanical and thermophysical properties of the composite bulk materials were also investigated. The composite powders and bulk materials showed good phase stability from room temperature to 1400oC and after heat-treatment at 1450oC for a long period, respectively. The bulk G5S5 had the highest microhardness of 15.2±2.2 GPa compared with the bulk G7S3 (14.1±1.9 GPa) and G3S7 (12.5±1.6 GPa). The bulk G5S5 also had the highest Youngs modulus of 266.5±13.9 GPa in comparison with the bulk G7S3 (261.5±13.8 GPa) and G3S7 (256.3±7.8 GPa). The bulk G3S7 has the highest fracture toughness of 1.96±0.11 MPa·m1/2, followed by the bulk G7S3 (1.63±0.07 MPa·m1/2) and G5S5 (1.60±0.09 MPa·m1/2). The CTEs of the bulk G3S7, G5S5 and G7S3 were 9.1-10.8×10-6, 9.1-10.8×10-6 and 9.3-10.8×10-6 K-1 in a temperature range of 200-1350oC, respectively. The CTEs of the bulk G7S3 has no obvious abnormal change during measuring, indicating the phase transitions of SrZrO3 were suppressed. The thermal conductivity of the bulk G7S3 was ~1.1 W·m-1·K-1 at 1000oC. Thus, the bulk G7S3 is considered as a promising thermal barrier coating material. |