Microstructure refinement-homogenization and flexural strength improvement of Al2O3 ceramics fabricated by DLP-stereolithography integrated with chemical precipitation coating process

• Published in: Journal of advanced ceramics Vol. 10; no. 4; pp. 790 - 808
• Main Authors: Nie, Guanglin, Li, Yehua, Sheng, Pengfei, Zuo, Fei, Wu, Haolin, Liu, Leiren, Deng, Xin, Bao, Yiwang, Wu, Shanghua
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.08.2021; Springer Nature B.V; School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,China%State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China
• Subjects: Al2O3 ceramic; Aluminum oxide; Ceramic coatings; Ceramic powders; Ceramics; Characterization and Evaluation of Materials; Chemical precipitation; Chemistry and Materials Science; Component reliability; Composites; Flexural strength; Glass; Grain size; Heat sinks; Homogenization; Lithography; Materials Science; Microstructure; Morphology; Nanotechnology; Natural Materials; reliability; Research Article; stereolithography; Structural Materials; Thermal conductivity; Three dimensional printing; Weibull modulus; Yttrium oxide; ceramic; flexural strength; microstructure; stereolithography; reliability; Al; thermal conductivity; O; Al2O3 ceramic
• ISSN: 2226-4108; 2227-8508
• DOI: 10.1007/s40145-021-0473-2

In this study, the chemical precipitation coating (CP) process was creatively integrated with DLP-stereolithography based 3D printing for refining and homogenizing the microstructure of 3D printed Al 2 O 3 ceramic. Based on this novel approach, Al 2 O 3 powder was coated with a homogeneous layer of amorphous Y 2 O 3 , with the coated Al 2 O 3 powder found to make the microstructure of 3D printed Al 2 O 3 ceramic more uniform and refined, as compared with the conventional mechanical mixing (MM) of Al 2 O 3 and Y 2 O 3 powders. The grain size of Al 2 O 3 in Sample CP is 64.44% and 51.43% lower than those in the monolithic Al 2 O 3 ceramic and Sample MM, respectively. Sample CP has the highest flexural strength of 455.37±32.17 MPa, which is 14.85% and 25.45% higher than those of Samples MM and AL, respectively; also Sample CP has the highest Weibull modulus of 16.88 among the three kinds of samples. Moreover, the fine grained Sample CP has a close thermal conductivity to the coarse grained Sample MM because of the changes in morphology of Y 3 Al 5 O 12 phase from semi-connected (Sample MM) to isolated (Sample CP). Finally, specially designed fin-type Al 2 O 3 ceramic heat sinks were successfully fabricated via the novel integrated process, which has been proven to be an effective method for fabricating complex-shaped Al 2 O 3 ceramic components with enhanced flexural strength and reliability.