Piezoelectric properties of (Na1−xKx)NbO3‐based lead‐free piezoelectric ceramics and their application in knocking sensor. Issue 12 (12th August 2017)

• Record Type: Journal Article
• Authors: Kim, Dae‐Hyeon; Lee, Tae‐Gon; Cho, Sung‐Hoon; Lee, Ku‐Tak; Kang, Chong‐Yun; Lee, Won‐Kyoung; Lee, Chung‐Kook; Nahm, Sahn
• Is Part Of: Journal of the American Ceramic Society. Volume 100:Issue 12(2017)
• Page Start: 5367
• Page End: 5373
• Publication Date: 2017-08-12
• Subjects: lead‐free ceramics -- piezoelectric materials/properties -- sensors; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.15107
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: Piezoelectric knocking sensors with a dense microstructure were fabricated at 960°C for 2 hours using various CuO‐added (Na0.5 K0.5 )NbO3 (NKN)‐based piezoelectric ceramics. The practical sensitivity ( S P ) of the knocking sensor, which is the ability to detect the knocking of a car engine, was influenced by the g 33 × k p value of the piezoelectric ceramics, indicating that the g 33 × k p can be considered a figure of merit of the piezoelectric ceramics used in the knocking sensor. The knocking sensor synthesized using the CuO‐added 0.95(Na0.5 K0.5 )(Nb0.95 Sb0.05 )O3 –0.05CaTiO3 (CNKNS–CT) ceramic, which showed a g 33 of 25.7 Vm/N and k p of 0.46, exhibited a high S P of 119 mV/g at the resonance frequency. The S P of the commercial knocking sensor, which was synthesized using the Pb(Zr, Ti)O3 (PZT)‐based ceramic, was 112 mV/g at the resonance frequency. Hence, the knocking sensor fabricated using the CNKNS–CT piezoelectric ceramic can be used to replace the commercial PZT‐based knocking sensor.