Preparation and properties of ZTA ceramics using blast furnace slag as sintering additives. (6th March 2019)

• Record Type: Journal Article
• Authors: Ma, Decao; Chen, Haitao; Cheng, Xiangqian; Gao, Kai; Wang, Lei; Zhang, Liwei; Wang, Hailong; Zhang, Rui; Lu, Hongxia
• Is Part Of: Materials research express. Volume 6:Number 6(2019)
• Publication Date: 2019-03-06
• Subjects: ZTA ceramics -- gehlenite crystal phase -- mechanical properties -- microstructure -- blast furnace slag(BFS); Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab07da
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: ZTA ceramics with Blast furnace slag (BFS) powders as sintering additives were prepared by pressureless sintering. Chemical composition, physical characteristic, thermal characteristic and microstructure of BFS powders and ZTA ceramics were studied by x-ray Fluorescence Spectrometry (XRF), x-ray diffraction (XRD), differential scanning calorimetry (DSC), laser particle size analyzer and Scanning Electron Microscope (SEM), respectively. The results show that the main constitution of BFS powders is glass phase (SiO2, CaO, and MgO), which is traditional sintering additive for ceramics. Besides, gehlenite crystal phase can be obtained when BFS powders are calcined at 850∼950 °C. When ZTA samples with 5 wt% BFS were sintered at 1550 °C for 2 h and soaked for 1 h at 950 °C during the cooling process, its relative density reached to 97%, bending strength is 375 MPa, which is much higher than that of mono-phase ZTA, and fracture toughness is 3.97 MPa·m 1/2 . The results of XRD and SEM demonstrate that the micro crystal phase of gehlenite exists at the grain boundaries, which can improve the mechanical properties of ZTA ceramics. The addition of BFS powders can not only reduce the sintering temperature, but also improve the strength of the ceramics.