Cracking mechanism in laser directed energy deposition of melt growth alumina/aluminum titanate ceramics |
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Authors: | Yunfei Huang Dongjiang Wu Xuexin Yu Guangyi Ma Jun Han Hong Wang Fangyong Niu |
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Affiliation: | 1. Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, Dalian, Liaoning, P. R. China;2. Department of Spine Surgery, Dalian Municipal Central Hospital Affiliated of Dalian Medical University, Dalian, P. R. China |
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Abstract: | Thanks to its advantages of high efficiency and near-net shaping, laser directed energy deposition (LDED) is rapidly becoming a remarkable preparation technology for high-purity ceramics. However, the cracking problem in shaping process is always a great challenge for LDED to achieve industrial application. For this purpose, alumina/aluminum titanate melt-growth ceramics (A/AT MGCs) were prepared using LDED system, and the corresponding finite element thermal analysis model was developed. The solidification behavior and cracking mechanism of A/AT MGCs were investigated based on the thermal analysis model, and the influence of process parameters on the cracking characteristics was revealed with experiments. Results show that the crack morphology and distribution are controlled by microstructure and temperature gradient together. The scanning speed of 100–150 mm/min, with better microstructure and lower temperature gradient, is a preferred process window. This study provides theoretical guidance and technical support for the cracking suppression during LDED shaping of ceramics. |
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Keywords: | additive manufacturing alumina/aluminum titanate ceramics cracking laser directed energy deposition |
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