Densification and Phase Transformation in Multi-Layered Graded Si3N4–TiN Components Produced by Field-Assisted Sintering

Autor: Dong-Tao Lin, Li-Juan Yuan, Peng-Jie Zhang, Fei Zuo, Kevin Plucknett, Salvatore Grasso, Hong-Jian Wang, Hua-Tay Lin
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Materials, Vol 12, Iss 18, p 2900 (2019)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma12182900
Popis: The structural and/or functional design of multiphase ceramics, along with their processing, are timely research topics in the area of field-assisted sintering techniques, such as spark plasma sintering, especially for systems containing both electrically insulating and conductive phases. In the present study, spark plasma sintering of Si3N4−TiN composites was investigated by changing the TiN particle size and electrical current waveform. Their combined effects on both the densification behavior and α-to-β phase conversion of the Si3N4 matrix was studied and compared by means of a thermodynamic approach and dilatometric measurements. Through the control of TiN phase characteristics and heating mode, double-layered Si3N4-based components were also prepared using a one-step spark plasma sintering process, which was compared with conventional hot-pressing. It was shown that the size of the conductive TiN phase has a significant influence on the particle rearrangement, with the formation of a liquid phase, and the solution−diffusion−precipitation process, through the field-induced local heating and electrowetting mechanisms. Moreover, the contribution of current pulsing to the densification and α-to-β conversion of the layered Si3N4-based components was mostly dependent upon the particle size distribution and content of the TiN phase, indicating that the electric-field effect is dependent upon current path.
Databáze: Directory of Open Access Journals
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