Thermal shock and thermal fatigue resistance of Al2O3/(W,Ti)C/TiN/Mo/Ni multidimensional graded ceramics |
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| Authors: | Xiuying Ni Jun Zhao Feng Gong Gang Li |
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| Affiliation: | 1. School of Transportation, Ludong University, Yantai, China;2. Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE, School of Mechanical Engineering, Shandong University, Jinan, China |
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| Abstract: | Al2O3/(W, Ti)C/TiN/Mo/Ni multidimensional graded ceramics and homogeneous reference ceramic were prepared by two step hot press sintering. The thermal shock and thermal fatigue resistance of the multidimensional graded ceramics were tested using the water quenching method. Scanning electron microscopy (SEM) and optical microscope were used to investigate microscopic failure mechanism of ceramics. The results showed that the retained flexural strength of two-dimensional and one-dimensional graded ceramics was almost same, but higher than that of the homogeneous ceramic. The crack growth (?c) of homogeneous ceramic increased rapidly, while that of two-dimensional graded ceramics is the lowest. Hence, thermal fatigue resistance of the two-dimensional graded ceramics was highest. The residual compressive stress in the first layer induced by the optimal graded structure played an important role. In addition, the increasing toughness on the crack propagation path by adding different amounts of metals was also a contributing factor. |
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| Keywords: | multidimensional graded ceramics thermal fatigue thermal shock water quenching |
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