In situ fabrication of continuously graded Si3N4 ceramics via DC field-assisted hot pressing. (May 2022)

• Record Type: Journal Article
• Authors: Xu, Jingkun; Liu, Zetan; Zhang, Jie; Li, Fei; Qin, Xiaowei; He, Shan; Xie, Zhipeng
• Is Part Of: Scripta materialia. Number 213(2022)
• Publication Date: 2022-05
• Subjects: Liquid-phase sintering -- Field-assisted sintering technique -- Peltier effect -- Functionally graded materials -- Hardness; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2022.114600
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The effects of various DC electric fields (0–167 V/cm) on liquid-phase hot pressing of Si3 N4 ceramics were investigated. The application of a DC field promoted the α→β phase transformation of Si3 N4 near the cathode while inhibiting it near the anode. As a result, the Si3 N4 ceramics with continuously graded microstructures and mechanical properties were in situ fabricated from a homogeneous raw powder. Although the DC field-driven migration of Mg 2+ and Y 3+ ions was recorded, the graded phase transformation phenomenon was linked to the Peltier effect, which led to additional heating at the cathode and cooling at the anode. Graphical abtract: Image, graphical abstract