【摘 要】
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A type of W/Cr co-doped Bi4Ti3O12 (ab.BTWC) ceramics were synthesized utilizing the traditional solid-state reaction process,end its thermal shock resistance (T
【机 构】
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MOE Key Laboratory of Deep Earth Science and Engineering,College of Architecture and Environment,Sic
论文部分内容阅读
A type of W/Cr co-doped Bi4Ti3O12 (ab.BTWC) ceramics were synthesized utilizing the traditional solid-state reaction process,end its thermal shock resistance (TSR) as well as the crack growth behavior was systemati-cally investigated by water quenching technology.It can be found by the succeeded fractographic analysis that many edge thermal cracks began to appear in the samples subjected to thermal shock with △T =400 ℃.Ac-cording to an integrated TSR model,the critical thermal-shock temperature difference △Tcwas calculated to be 356 ℃.Moreover,it can be noticed that the indenter induced crack growth behaviors under thermal shock loads presented three stages,i.e.no growth,large growth,and moderate growth,along with △T increasing from 0 ℃ to 700 ℃.Finally,the asymmetry of P-E hysteresis loops was observed and understood by the orientated polarization of defect dipoles after the sample was thermally shocked,while the water-quenching process above the Curie temperature of the ceramics could lead to a random orientation of the defect dipoles.This research can not only evaluate the service conditions of Bi4Ti3O12 high-temperature piezoceramics,but also understand the failure mechanism of bismuth layer structured ferroelectric ceramics in the case of thermal shock.
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